Clinic: Spiders

General

With spider bites, identification of the culprit is particularly difficult.

If the spider is not brought in for identification, then identification on the basis of the patient's description is highly questionable. If the spider is available for identification, it is possible in most cases to achieve a conclusive result if identification is performed by an expert.

Clinical data from the literature cannot be related to a conclusively identified species in many cases. The clinical information available comes from bites caused by various spider species, and it may be that the individual specimens were reliably identified, identified according to unclear criteria or not identified at all. Indirect criteria, such as a course of envenoming considered typical for a particular species of spider, and geographical criteria are often used to aid in identification.

The range of differential diagnoses is wide:

• Primary bacterial, fungal and parasitic cutaneous infections
• Vascular occlusive or venous disease
• Pyoderma gangrenosum
• Necrotizing fasciitis
• Neoplastic ulcers
• and many others

Isbister et al (2005a) addressed the problem of “skin ulcers of uncertain aetiology presenting as suspected spider bites” which is the majority of patients clinician must deal with. 

“Approach to the investigation and diagnosis of necrotic skin ulcers of uncertain etiology presenting as suspected spider bites*

* Modified from Isbister and Whyte (2004).

 A Establish whether or not there is a history of spider bite 

• Clear history of spider bite (better if spider is caught)
• Refer to information on definite spider bites
• No history of spider bite
• Investigation should focus on the clinical findings: ulcer or skin lesion
• Provisional diagnosis of a suspected spider bite is not helpful

B Clinical history and examination

• Important considerations
• Features suggestive of infection, malignant processes, or vasculitis
• Underlying disease processes: diabetes, vascular disease
• Environmental exposure: soil, chemical, infective
• Prescription medications
• History of minor trauma
• Specific historical information about the ulcer can assist in differentiating some conditions
• Painful or painless
• Duration and time of progression
• Preceding lesion

C Investigations

• Skin biopsy
• Microbiology: contact microbiology laboratory prior tocollecting specimens so that appropriate material and transport conditions are used for fungi,
• Histopathology
• Laboratory Investigations: may be important for underlying conditions (autoimmune conditions, vasculitis), including, but not be limited to
  • Biochemistry (including liver and renal function tests
  • Complete blood count and coagulation studies
  • Autoimmune screening tests, cryoglobulins
• Imaging
  • Chest radiograph
  • Colonoscopy
  • Vascular function studies of lower limbs

D Treatment

• Local wound management
• Treatment based on definite diagnosis or established pathology
• Investigation and treatment of underlying conditions may be important, (e.g., pyoderma gangrenosum or diabetes mellitus)

E Follow-up and monitoring

• The diagnosis may take weeks or months to be established so patients must have ongoing follow-up.
• Continuing management: coordinated with multiple specialties involved as necessary.”

Examine for venom effects

Local Effects

Bitesite

• Pain,
• Tender local (spreading) swelling,
• Lymphangiopathy and lymphadenopathy,
• Necrotic soft tissue.

Urticating hair contact
-Skin

• Dermatitis (urticaria, papular dermatitis); itching of the skin can persist for several months.

-Eyes

• Keratitis, conjunctivitis, iritis, chorioretinal scarring.

• Urticating hairs which entered the eye (slit lamp).

Haematological effects

Haemolysis 
Anaemia developing rapidly or with a long delay.

Neurological effects

Neuromuscular dysfunction
Muscle fasciculations and spasms, local and generalised.
Abdominal rigidity, simulating acute abdomen.
Autonomic nervous system
-Cholinergic effects
Vomiting; sweating; hypersalivation and hyperlacrimation. Priapism.
Bradycardia, arterial hypotension, shock. 
-Adrenergic effects 
Tachycardia, arterial hypertension, myocardial failure, pulmonary oedema (cardiogenic + ?non-cardiogenic component), cardiac ischaemia, shock, arrhythmias.

Species-specific envenoming pattern
The assessment of the envenoming pattern is based on the data from publication in which the identification of the snakes is clearly specified and in accordance with accepted criteria. 

Common features of medically important spider envenoming

Important to distiguish between spider envenoming with

²NEUROTOXIC ARANEISM 

Neurological effects (autonomic and somatic nervous systems)

Experimental and clinical observations suggest that the major systemic effects of envenoming are caused by endogenous catecholamines and acetylcholine, which are released in response to Atrax sp. and Hadronyche sp., Latrodectus sp., Phoneutria sp. venom (possibly also to the venom of other species, e.g.  Steatoda sp.). As these are transmitters of the sympathetic, parasympathetic and somatic nervous systems, the resulting clinical symptoms of envenoming are dealt with in the section "Neurological effects".

with cardiovascular and pulmonary effects secondary to autonomic nervous system effects.

¹NECROTIC LOXOSCELISM (Loxosceles sp.)

subdivided into

Cutaneous loxoscelism

and

Cutaneous-haemolytic loxoscelism 

^A  Atrax sp. and Hadronyche sp.

Local effects

(Severe) local pain, local erythema otherwise minimal local envenoming (Sutherland and Tibballs 2001).

Neurological effects (autonomic and somatic nervous systems)

NEUROTOXIC ARANEISM
A substantial proportion of the envenoming symptoms caused by Atrax sp. and Hadronyche sp. are explained by the fact that these venoms affect the autonomic nervous system and neuromuscular conduction (Sutherland and Tibbals 2001). The envenoming syndromes caused Atrax sp. and Hadronyche sp. bites are indistinguishable (Miller et al. 2000). Both parts of the autonomic nervous system and the somatic nervous system are stimulated. This results in cholinergic effects (vomiting, profuse sweating, hypersalivation), adrenergic effects (arterial hypertension, tachycardia, cardiac arrhythmias) and effects on the skeletal musculature (fasciculations, spasms).
At the early stage of envenoming, perioral numbness, tongue spasms. Nausea, vomiting, abdominal pain, sweating, hypersalivation and hyperlacrimation, dyspnoea. Muscle fasciculations and spasms, local and generalised. Confusion, coma. Arterial hypertension, pulmonary oedema. These signs and symptoms can develop within a period of 10 min. Thus, the necessity of an efficient first aid method (see below) (Fisher et al. 1980; Harrington et al. 1999; Hartman and Sutherland 1984; Isbister et al 2005b; Miller et al 2000; Sutherland and Tibballs 2001).
“Patients are highly unlikely to develop envenoming after 2 hours, but, until this is confirmed by prospective studies, it is important to observe patients with suspected funnel-web spider bites for 4 hours” (Isbister et al 2005b).

For treatment: see section 'CLINICAL MANAGEMENT' below.

^B  Latrodectus sp.

Local effects

Local burning pain during the bite (may be absent and thus the bite may go unobserved). The pain may spread in the direction of the regional lymph nodes within minutes (5–15 min). Local erythema, oedema, hypaesthesia (Maretic 1978, 1983; Rauber 1983–84). So-called "target lesions" (circle of reddened skin surrounding a pale centre) with a diameter of 2–6 cm can develop within 1–2 h and disappear again after 8–12(–24) h (Vance et al. 1986).
Severe in more half of patients, pain lasting > 24h, unable to sleep in a third of patients because of pain (Isbister and Gray 2003a).

Neurological effects (autonomic and somatic nervous systems)

NEUROTOXIC ARANEISM
The time between the bite and the onset of systemic signs and symptoms of envenoming was 15–60 min (Latrodectus indistinctus) (Müller 1993).
Abdominal (accompanied by abdominal rigidity, simulating acute abdomen - L. indistinctis, L. mactans) and back pain is frequent.
Autonomous nervous system effects include nausea, vomiting, sweating, tachycardia, hypertension. Irritability and agitation.
“Facies latrodectismica” (L. mactans = ?L. tredecimguttatus) (Maretic 1983).
If untreated signs and symptoms may persist for days (Maretic 1978, 1983, Rauber 1983–84)
Isbister and Fan (2011) summarize the clinical effects of widow spiders from different regions of the world: L hasselti, L. mactans, L. curacaviensis, L. indistinctis, L. geometricus, L. mactans, L. tredecimguttatus. The positive identification varies between 100% and not specified (see comment above).

For treatment: see section 'CLINICAL MANAGEMENT' below.

^C  Loxosceles sp.

Local effects

NECROTIC LOXOSCELISM (Cutaneous loxoscelism) 
Mild envenoming with mild local effects (majority of cases)
Often no pain initially (thus bites often go unnoticed). If only a small amount of venom is injected, mild pain, erythema and oedema possible within 8 h; possibly development of insignificant necrosis (Berger 1973).

Severe envenoming with necrosis (very rare) and time course of the development of the lesion
“The bite may be painless initially, but there is progressive local discomfort over the next 2-24 hours. Stinging or burning pain develops with local erythema, itching and indurated swelling. Between 12-72 hours post-bite, a painful, tender ischaemic lesion appears, the ‘red-white-and-blue’ sign, its outer ring coloured red (vasodilatation), white (vasoconstriction) and central blue (pre-necrotic cyanosis) with serous or haemorrhagic vesicles, or blisters. It may spread gravitationally. Over the next 3-7 days, a black necrotic eschar develops in 60% of cases, which sloughs in a few weeks, sometimes leaving a deep necrotic ulcer.” (Warrell 2023; see also Sams et al 2001a; Table IV Typical evolution of Loxosceles lesion)).
Obvious necrosis within 24–48 h, often with irregular borders (Efrati 1969; Wasserman and Anderson 1983–84).
Time course of healing
Time to healing 5 to > 17 weeks (mean 5.6 weeks); for severity grad 1 (mild oedema, punctum, no necrosis) mean 8 days, severity grade 2 (erythema, mild oedema, bulla, necrosis ≤ 1cm²) mean 22 days, severity grade 3 (extensive erythema, oedema, bulla, ulcer / skin necrosis > 1cm²) mean 74 days (Sams et al. 2001b).

NECROTIC LOXOSCELISM (Cutaneous-haemolytic loxoscelism)
additionally to abive described cutaneous effects:

Haematological effects

Presentation of patients with systemic envenoming is with fever, malaise, vomiting, headache, rash and jaundice (Isbister and Fan 2011; Malaque et al. 2011).
Haemolysis
Haemolysis appears to occur rapidly or with a long delay after the bite (24–72 h) (de Souza et al. 2008; DiPaola et al. 2022; Futrell 1992; Laxton et al. 2024; Lucas 1988; Wasserman and Anderson 1983–84; Rosen et al. 2012). Acute renal failure (AKI) is less frequent and is associated with poor outcomes (Isbister and Fan 2011). AKI is infrequent and only occurred in cases manifesting massive haemolysis (de Souza et al. 2008; Malaque et al. 2011).
Laboratory parameters should be assessed over a period of 3 days after the bite, as haemolysis in particular may develop after a long delay: Haemoglobin, haematocrit, LDH, haptoglobin, clotting status, including platelets, haemoglobinuria.
Clotting effects
Although disseminated intravascular coagulation is usually listed as part of systemic loxoscelism, evidence to support it is scarce. In severe cases, mild thrombocytopenia occurs and a doubling of the clotting times which does not meet the criteria for disseminated intravascular coagulation (Isbister and Fan 2011).

Muscular effects

Muscular injury is reported for loxoscelism but in these cases there is only a small rise in creatine kinase to the low thousands U/L, which is unlikely to be clinically significant or contribute to the acute renal injury (de Souza et al. 2008).

For treatment: see section 'CLINICAL MANAGEMENT' below. 

^D  Phoneutria sp.

Local effects

Local pain, local oedema; referred regional pain (Bucaretchi et al. 2000, 2008).

Neurological effects (autonomic and somatic nervous systems)

NEUROTOXIC ARANEISM  

Phoneutria sp. venom also causes the release of neurotransmitters, primarily acetylcholine and noradrenaline. However, the neurological effects of the venom do not seem to be very pronounced in cases of human envenoming (Lucas 1988).
Vomiting, sweating, drowsiness or agitation, arterial hypertension, tachycardia are observed; rarely, severe hypertension precipitating pulmonary oedema and shock (Bucaretchi et al. 2000, 2008).

For treatment: see section 'CLINICAL MANAGEMENT' below.

^E  Various other labidognath spiders

Local effects
Chiracanthium sp.
Verified bites by Cheiracanthium spiders from the United States and Australia: none with necrosis. Review of the international literature of verified Chiracanthium sp. bites found only one case of mild necrosis in the European species C. punctorium (Vetter et al. 2006).

Steatoda sp.
Prolonged pain (Isbister and Gray 2003b).
Intense pain, slight swelling, local sweating and horripilation (pilcerection or `gooseflesh') (Steatoda nobilis) (Warrell et al. 1991).

Neurological effects (autonomic and somatic nervous systems)

NEUROTOXIC ARANEISM

Steatoda sp.
"’Steatodism’ is similar to, but less severe than, latrodectism and may cause […] systemic effects. In severe cases the clinical effects are almost indistinguishable from Latrodectus bite.” (Isbister and Gray 2003b). Facial flushing and feverishness for the first few hours after the bite (Steatoda nobilis) (Warrell et al. 1991).

For treatment: see section 'CLINICAL MANAGEMENT' below.

^F  Various other mygalomorph spiders

Theraphosidae sp.; other mygalomorph species 

Urticating hair contact

Dermatitis (urticaria, papular dermatitis); itching of the skin can persist for several months (Cooke et al. 1973, Radcliffe 1977).
Keratitis, conjunctivitis, iritis, chorioretinal scarring (Chang et al. 1991, Hered et al. 1988, Stulting et al. 1983).

Bites

Local signs and symptoms variable; mostly mild (Poecilotheria fasciata, Euathlus vagans, Rhechosticta saltator, Psalmopoeus cambridgei (Schmidt 1989), bit also intense to severe (Pterinochilus murinus, Lampropelma nigerrimum) (Ahmed et al. 2009); and moderate to severe on Theraphosidae bites (Isbister et al. 2003b).

Lampropelma nigerrimum
Agnoizing, generalised visible muscle cramps developed over 48 h, increasing intensity, involving all muscle groups, each spasm lasting 30 s to 3-5 min., and persisted to day 4 after the bite and decreased thereafter to disappear by day 7. Serum Creatine kinase: 10x upper normal value (Ahmed et al. 2009).
Pterinochilus murinus
Agonizing, generalised muscle cramps which developed 24 h after the bite (Ahmed et al. 2009).
Poecilotheria regalis
Persistent local cramps in the affected hand (Ahmed et al. 2009).
Eumenophorus, Selenocosmia and Stromatopelma and other genera of Old-World tarantulas
Case reports mentioned similar muscle cramps (Ahmed et al. 2009).

For treatment: see section 'CLINICAL MANAGEMENT' below. 

Publications reporting broadly on spider envenoming

Isbister et al. (2005a), Isbister and Fan (2011), Isbister and White (2004) Nentwig et al. (2017), Vetter and Isbister (2008)

Europe
Gnädinger et al. (2013), Nentwig et al (2013) 

Species-specific publications: see ‘References’ at the end of the file.

Clinical management

See also Clinical Management: spiders

for advice on post-First Aid measures, diagnosis (clinical, laboratory) and treatment (supportive, antivenom).

First AID

Pressure-immobilization is recommended only for bites by Australian funnel web spiders (Warrell 2023).
Atrax sp. and Hadronyche sp.
If an extremity is affected, a compression bandage is applied and the extremity is immobilised (Sutherland and Duncan 1980, Sutherland and Tibballs 2001)

Pressure-immobilisation-technique 
Early removal of compression bandage results in rapid clinical deterioration (Miller et al. 2000).
It is imperative to apply pressure-immobilization as early as possible, ideally within 10 minutes after the bite. The bandage must remain in place until the envenomation syndrome has completely resolved. The first aid knowledge of the population is dangerously deficient (Miller et al. 2000).

Local treatment

Pain control 
Tetanus prophylaxis
Standard wound care
Systemic antibiotics: standard indications
WHO (2010)

Latrodectus sp.
Antivenom should be administered in most cases for pain relief alone (Isbister and Gray 2003).
The use of antivenom significantly shortened the duration of symptoms in severe envenomation (Clark et al. 1992). The use of calcium gluconate to relief painful muscle spasms is not based on sufficient evidence (Warrell 2023).

Loxosceles sp.
Very conflicting positions on treatment. There are no controlled clinical studies on the various recommended forms of treatment.
Most Loxosceles bites heal by themselves with routine wound care, elevation of the affected extremity, local cooling to reduce local inflammatory reactions, dressing changes, antibiotic treatment if required (Futrell 1992).
Early surgical excision is avoided; early surgical excision creates more problems than it solves (Futrell 1992)
There is no sound evidence for the use of dapsone, antihistamines, corticosteroids, hyperbaric oxygen, and antibiotics, such as tetracycline and metronidazole, for necrotic loxoscelism. Surgical debridement for necrotic lesions is not recommended (Swanson et al. 2005; Warrell 2023).

Various mygalomorph spiders
Theraphosidae
Eye: topical corticosteroids, initially 10 times a day, then slow dose reduction over 3 months. Improvement of the inflammatory reaction within 48 h; resorption of the urticating hairs within 10 months (Chang et al. 1991).
 

Systemic supportive treatment

A general understanding of emergency medicine is required, or can be found in emergency medicine guidelines, e.g.ABCDE approach, WHO-ICRC Basic Emergency Care.

• Comprehensive ABCDE approach

• ICRC Basic Emergency Care: approach to the acutely ill and injured (SAMPLE  and ABCDE approach: first module)

Obey Spider-specific features

see 'Species-specific envenoming pattern' above.

Key issues

Atrax sp. and Hadronyche sp.
Respiratory insufficiency, pulmonary oedema
Oxygen; endotracheal intubation and artificial respiration. Caution is required if using diuretics to treat the pulmonary oedema if there is concurrent hypovolaemia (Fisher et al. 1980, Sutherland and Tibbals 2001).
Hypovolaemia
Careful treatment if there is concurrent pulmonary oedema. The pulmonary oedema is probably non-cardiogenic and attributable to increased pulmonary capillary permeability (Fisher et al. 1980, Sutherland and Tibbals 2001).
Latrodectus sp.
Life-threatening autonomous effects occur and resulted in reported deaths.
Phoneutria sp.
Life-threatening effects as in Latrodectus sp.. Envenoming, however, in most cases milder.

Neurotoxic envenoming
There is no sound evidence for the use of intravenous calcium gluconat, β-blockers, and atropine for neurotoxic envenoming (Warrell 2023).
Contra-indicated medications and medications to avoid
Opiates and other centrally sedating medications, such as benzodiazepine, are not only largely ineffective, but also dangerous. They can lead to respiratory depression in patients with pre-existing damage (Müller 1993).
There is no sound evidence for the use of intravenous calcium gluconat, β-blockers, and atropine for neurotoxic envenoming (Warrell 2023).

Loxosceles sp. 
Severe local envenoming with necrosis  - NECROTIC LOXOSCELISM (Cutaneous loxoscelism) 
Since decades controversially discussed, both incidence and treatment. See Ispister et al. (2005a) discussing "Spider bites: addressing mythology and poor evidence".
More recently severe local envenoming with necrosis is rgarded as very rare and certain treatments (e.g. dapsone) are regared as lacking a solid evidence base. Many differential diagnoses have been falsely attributed to Loxosceles bites.
Severe anaemia following haemolysis (rare) with AKI (very rare)
Laboratory parameters should be assessed over a period of 3 days after the bite, as haemolysis in particular may develop after a long delay: Haemoglobin, haematocrit, LDH, haptoglobin, clotting status, including platelets, haemoglobinuria.

Specific treatment (antivenoms)

ANTIVENOMS

Indication and selection of antivenom needs to be based on the evidence available in the respective region where the envenoming occurs.

Overview

• Isbister et al (2003a)

Experiences with antivenoms

Atrax sp. and Hadronyche sp.

Funnel-web spider antivenom (CSL, Parkville, Australia).
Indications
Systemic envenoming (Sutherland and Tibbals 2001):

• Muscle fasciculations in the region of the affected extremity or distant from the site of the bite, then usually initially the lips and tongue, hypersalivation and hyperlacrimation, piloerection, tachycardia,

• Arterial hypertension (in the late stage of envenoming arterial hypotension), dyspnoea, disorientation, impaired consciousness.

Administration of antivenom in cases of systemic envenoming (for criteria, see above)
It is important that antivenom doses are repeated until the desired clinical effect is achieved. Monitoring and treatment of complicated cases of envenoming in an intensive care unit (Dieckmann et al. 1989, Sutherland 1992, Miller et al. 2000).

Efficacy

• Hartman and Sutherland (1984)
  9 Atrax sp. bites in patients between 3 and 82 years (identification: A. robustus 6/9, A. formidabilis 2/9 ((=Hadronyche formidabilis)), A. bermagui ((?species unkown)) 1/9). Open, uncontrolled, prospective study for evaluation of the efficacy of Funnel-web spider antivenom and adverse reactions to it. Antivenom dose according to the study protocol: 2 vials as the minimum initial dose in cases of mild envenoming. Repetition of this dose if there is no improvement 15 min after the initial dose. Twice this dose in cases of severe envenoming; antivenom is administered i.v. Premedication with an antihistamine with as low a sedative effect as possible and 100 mg of hydrocortisone sodium succinate.
  Study results
  In all 9 patients there was improvement of the signs and symptoms of envenoming within a period of hours. The patients were able to leave hospital after between 1 and 3 days. The authors argue that without antivenom administration in this group of patients fatalities would have been expected, as well as a hospitalisation period of 2–3 weeks. No adverse reactions were observed that could be conclusively attributed to the antivenom treatment.

• Dieckmann et al. (1989) 
  3 Hadronyche sp. bites (identification: H. versuta 1/3, H. infensa 1/3, H. cerberea 1/3). In all 3 patients there was obvious improvement of the signs and symptoms of envenoming coinciding with the administration of antivenom. The authors note the necessity of repeated administration of antivenom.
• Sutherland (1992)
  3 Funnel-web spider bites (identification: A. robustus 1/3, H. cerberea 1/3, Atrax sp. 1/3). In all 3 patients there was obvious improvement of the signs and symptoms of envenoming coinciding with the administration of antivenom. The authors note the necessity of repeated administration of antivenom.
• Miller et al. (2000) 
  5 cases of Hadronyche sp. bites. Identification: morphological (male H. cerberea 2/5, male H. formidabilis 1/5), male H. infensa 1/5,male Hadronyche sp. 1/5). Systemic signs of envenoming, in particular early pulmonary oedema, respond rapidly to antivenom. Antivenom requirements may be greater than for Atrax sp. envenoming.

Assessment of the value of antivenom in the treatment of Atrax sp. and Hadronyche sp. envenoming

• Antivenom has decidedly transformed the treatment of Atrax sp. and Hadronyche sp. envenoming. According to the available study and case reports, antivenom dramatically reduces case fatality and mortality. The rate of adverse reactions appears to be very low.
• see also (Isbister et al. 2003a, Isbister and Fan 2011, Ryan et al. 2017).

Latrodectus sp.

1. Spider antivenom (SAIMR, Johannesburg, South Africa)

• Müller (1993)
  Dose
  1 vial of 5 ml i.m. (29/30); within 12 h after the bite 20/30, between 12 and 24 h after the bite 3/30, after 3–5 days 3/30, no time given 3/30; 2 vials administered 2/30.
  Efficacy
  All patients improved within 6–12 h after antivenom administration. In 19/30 the symptoms of envenoming disappeared completely within 6 h, in 7 the effect was dramatic, with clear improvement within 30–60 min. 4 patients were symptomatic until they were given antivenom between 3 and 5 days after the bite.
  Adverse reactions
  No allergic reactions 29/29.
• La Grange (1990) 
  One patient still had the classic signs of Latrodectus envenoming 36 h after the bite, as well as pulmonary oedema. She received antivenom 48 h after the bite. She started to improve within 2 h.

2. Red-back spider antivenom (CSL, Parkville, Australia) an others

• Sutherland (1992) 
  256 cases in which Red-back spider antivenom was used and which are sufficiently well documented.
  Dose
  1 vial 217/256, 2 vials 33/256, 3 vials 5/256, 4 vials 1/256.
  Efficacy
  Good results, even when antivenom was administered up to 120 h after the bite.
  Adverse reactions
  Immediate hypersensitivity 2/256, delayed reactions (serum sickness)3/256.
  
• Isbister and Gray (2003a) 
  68 Latrodectus hasselti bites. Identification: Spider immediately collected and expertly identified. Hospitalized patients: 23/68 with antivenom treatment (i.m.) in 6/23. No significant difference in pain relif and duration of systemic effects between the treated and non-treated group.
• Stanford et al. (2007)
  Fab2 antivenom.

Application

• Ellis et al. (2005)
  “Red-back spider antivenom was initially effective by both i.m. and i.v. routes. The study generates the hypothesis that at 24 h, significantly more patients are pain-free with i.v. administration.”

• Isbister et al. (2008)
• „The difference between IV and IM routes of administration of widow spider antivenom is, at best, small and does not justify routinely choosing one route over the other. Furthermore, antivenom may provide no benefit over placebo”.

3. Antivenom Latrodectus (Black Widow) Equine Immune F(ab')₂  (USA)

• Dart et al. (2019)
  The Efficacy of Antivenin Latrodectus (Black Widow) Equine Immune F(ab')₂ Versus Placebo in the Treatment of Latrodectism: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial.
• ClinicalTrials.gov. Black Widow Spider Antivenin for Patients With Systemic Latrodectism. (BWSP3) https://clinicaltrials.gov/study/NCT00657540
  Phase III, multi-center, double-blind, randomized controlled study (ongoing).

Assessment of the value of antivenom in the treatment of Latrodectus sp. envenoming

• The currently available results on the effectiveness of Latrodectus antivenoms provide contradictory results. (Isbister et al. 2003a, Isbister and Fan 2011, Ryan et al. 2017).

• New develoments need to be followed-up.

Loxosceles sp.

Loxosceles laeta antivenom

Available in South America.

Assessment of the value of antivenom in the treatment of Loxosceles sp. envenoming

• Antivenom treatment has little significance due to the purely practical reason that most patients do not consult a doctor until >24 hours after the bite. According to experimental investigations, antivenom no longer has an effect on the necrotising process at this point in time (Futrell 1992, Lucas 1988).
• “Of all the evaluated interventions, antivenom showed the greatest therapeutic potential, but there are no adequately performed clinical experiments that may assure the efficacy of the different treatments in loxoscelic bites or lead to a greater consensus of which would be the ideal therapy for the treatment of loxoscelism.” (Pauli et al. 2006).
• see also (Isbister et al. 2003a, Isbister and Fan 2011, Ryan et al. 2017).
• New develoments need to be followed-up.

References

Reviews

• Isbister GK, White J, Currie BJ, Bush SP, Vetter RS, Warrell DA. Spider bites: addressing mythology and poor evidence. Am J Trop Med Hyg. 2005a Apr;72(4):361-4; author reply 364-7. PMID: 15827269.
• Isbister GK, Fan HW. Spider bite. Lancet. 2011 Dec 10;378(9808):2039-2047. Epub 2011 Jul 15. PMID: 21762981. https://doi.org/10.1016/s0140-6736(10)62230-1
• Isbister GK, White J. Clinical consequences of spider bites: recent advances in our understanding. Toxicon. 2004 Apr;43(5):477-92. PMID: 15066408. https://doi.org/10.1016/j.toxicon.2004.02.002
• Nentwig W, Pantini P, Vetter RS. Distribution and medical aspects of Loxosceles rufescens, one of the most invasive spiders of the world (Araneae: Sicariidae). Toxicon. 2017 Jun 15;132:19-28. Epub 2017 Apr 10. PMID: 28408204. https://doi.org/10.1016/j.toxicon.2017.04.007
• Vetter RS, Isbister GK. Medical aspects of spider bites. Annu Rev Entomol. 2008;53:409-29. PMID: 17877450. https://doi.org/10.1146/annurev.ento.53.103106.093503

Europe

• Gnädinger M, Nentwig W, Fuchs J, Ceschi A. Swiss prospective study on spider bites. Swiss Med Wkly. 2013 Sep 4;143:w13877. PMID: 24019004. https://doi.org/10.4414/smw.2013.13877
  Nentwig W, Gnädinger M, Fuchs J, Ceschi A. A two year study of verified spider bites in Switzerland and a review of the European spider bite literature. Toxicon. 2013 Oct;73:104-10. Epub 2013 Jul 18. PMID: 23872119. https://doi.org/10.1016/j.toxicon.2013.07.010

Original publications

• Ahmed N, Pinkham M, Warrell DA. Symptom in search of a toxin: muscle spasms following bites by Old World tarantula spiders (Lampropelma nigerrimum, Pterinochilus murinus, Poecilotheria regalis) with review. QJM. 2009 Dec;102(12):851-7. Epub 2009 Sep 23. Erratum in: QJM. 2010 Mar;103(3):203-4. PMID: 19776152. https://doi.org/10.1093/qjmed/hcp128
• Berger RS. The unremarkable brown recluse spider bite. JAMA. 1973 Aug 27;225(9):1109-11. PMID: 4740608.
• Bucaretchi F, Deus Reinaldo CR, Hyslop S, Madureira PR, De Capitani EM, Vieira RJ. A clinico-epidemiological study of bites by spiders of the genus Phoneutria. Rev Inst Med Trop Sao Paulo. 2000 Jan-Feb;42(1):17-21. PMID: 10742722.
• Bucaretchi F, Mello SM, Vieira RJ, Mamoni RL, Blotta MH, Antunes E, Hyslop S. Systemic envenomation caused by the wandering spider Phoneutria nigriventer, with quantification of circulating venom. Clin Toxicol (Phila). 2008 Nov;46(9):885-9. PMID: 18788004. https://doi.org/10.1080/15563650802258524
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• ClinicalTrials.gov. Black Widow Spider Antivenin for Patients With Systemic Latrodectism. (BWSP3) https://clinicaltrials.gov/study/NCT00657540
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• Government of South Australia. SA Health (2018) https://www.sahealth.sa.gov.au/wps/wcm/connect/public+content/sa+health+internet/clinical+resources/clinical+programs+and+practice+guidelines/infection+and+injury+management/toxins/snakebite+and+spider+bite+management
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• Hered RW, Spaulding AG, Sanitato JJ, Wander AH. Ophthalmia nodosa caused by tarantula hairs. Ophthalmology. 1988 Feb;95(2):166-9. PMID: 3262847. https://doi.org/10.1016/s0161-6420(88)33191-x
• Isbister GK, Gray MR. Latrodectism: a prospective cohort study of bites by formally identified redback spiders. Med J Aust. 2003a Jul 21;179(2):88-91. PMID: 12864719. https://doi.org/10.5694/j.1326-5377.2003.tb05442.x
• Isbister GK, Gray MR. Effects of envenoming by comb-footed spiders of the genera Steatoda and Achaearanea (family Theridiidae: Araneae) in Australia. J Toxicol Clin Toxicol. 2003b;41(6):809-19. PMID: 14677791. https://doi.org/10.1081/clt-120025346
• Isbister GK, White J. Clinical consequences of spider bites: recent advances in our understanding. Toxicon. 2004 Apr;43(5):477-92. PMID: 15066408. https://doi.org/10.1016/j.toxicon.2004.02.002
• Isbister GK, Whyte IM. Suspected white-tail spider bite and necrotic ulcers. Intern Med J. 2004 Jan-Feb;34(1-2):38-44. PMID: 14748912. https://doi.org/10.1111/j.1444-0903.2004.00506.x
• Isbister GK, Fan HW. Spider bite. Lancet. 2011 Dec 10;378(9808):2039-2047. Epub 2011 Jul 15. PMID: 21762981. https://doi.org/10.1016/s0140-6736(10)62230-1
• Isbister GK, Graudins A, White J, Warrell D. Antivenom treatment in arachnidism. J Toxicol Clin Toxicol. 2003 a ;41(3):291-300. PMID: 12807312. https://doi.org/10.1081/clt-120021114
• Isbister GK, Seymour JE, Gray MR, Raven RJ. Bites by spiders of the family Theraphosidae in humans and canines. Toxicon. 2003b Mar;41(4):519-24. PMID: 12657322. https://doi.org/10.1016/s0041-0101(02)00395-1
• Isbister GK, White J, Currie BJ, Bush SP, Vetter RS, Warrell DA. Spider bites: addressing mythology and poor evidence. Am J Trop Med Hyg. 2005a Apr;72(4):361-4; author reply 364-7. PMID: 15827269.
• Isbister GK, Gray MR, Balit CR, Raven RJ, Stokes BJ, Porges K, Tankel AS, Turner E, White J, Fisher MM. Funnel-web spider bite: a systematic review of recorded clinical cases. Med J Aust. 2005b Apr 18;182(8):407-11. PMID: 15850438. https://doi.org/10.5694/j.1326-5377.2005.tb06760.x
• Isbister GK, Brown SG, Miller M, Tankel A, Macdonald E, Stokes B, Ellis R, Nagree Y, Wilkes GJ, James R, Short A, Holdgate A. A randomised controlled trial of intramuscular vs. intravenous antivenom for latrodectism--the RAVE study. QJM. 2008 Jul;101(7):557-65. Epub 2008 Apr 8. PMID: 18400776. https://doi.org/10.1093/qjmed/hcn048
• La Grange MA. Pulmonary oedema from a widow spider bite. S Afr Med J. 1990 Jan 20;77(2):110. PMID: 2296727.
• Laxton SJ, Whetstone D. Loxosceles reclusa Envenomation Causing Acute Hemolytic Anemia: A Case Report on Loxoscelism. Cureus. 2024 Jul 12;16(7):e64413. PMID: 39130847; PMCID: PMC11317074. https://doi.org/10.7759/cureus.64413 (presumed)
• Lucas S. Spiders in Brazil. Toxicon. 1988;26(9):759-72. PMID: 3059583. https://doi.org/10.1016/0041-0101(88)90317-0
• Malaque CM, Santoro ML, Cardoso JL, Conde MR, Novaes CT, Risk JY, França FO, de Medeiros CR, Fan HW. Clinical picture and laboratorial evaluation in human loxoscelism. Toxicon. 2011 Dec 1;58(8):664-71. Epub 2011 Oct 2. PMID: 21986355. https://doi.org/10.1016/j.toxicon.2011.09.011
• Maretic, Z. (1978) Epidemiology of envenomation, symptomatology, pathology and treatment (genus Latrodectus). In Bettini, S.: Arthropod venoms. Springer, Berlin: 185-212
• Maretić Z. Latrodectism: variations in clinical manifestations provoked by Latrodectus species of spiders. Toxicon. 1983;21(4):457-66. PMID: 6353667. https://doi.org/10.1016/0041-0101(83)90123-x
• Miller MK, Whyte IM, White J, Keir PM. Clinical features and management of Hadronyche envenomation in man. Toxicon. 2000 Mar;38(3):409-27. PMID: 10669029. https://doi.org/10.1016/s0041-0101(99)00171-3
• Müller GJ. Black and brown widow spider bites in South Africa. A series of 45 cases. S Afr Med J. 1993 Jun;83(6):399-405. PMID: 8211456
• Nentwig W, Pantini P, Vetter RS. Distribution and medical aspects of Loxosceles rufescens, one of the most invasive spiders of the world (Araneae: Sicariidae). Toxicon. 2017 Jun 15;132:19-28. Epub 2017 Apr 10. PMID: 28408204. https://doi.org/10.1016/j.toxicon.2017.04.007
• Nentwig W, Gnädinger M, Fuchs J, Ceschi A. A two year study of verified spider bites in Switzerland and a review of the European spider bite literature. Toxicon. 2013 Oct;73:104-10. Epub 2013 Jul 18. PMID: 23872119. https://doi.org/10.1016/j.toxicon.2013.07.010
• Pauli I, Puka J, Gubert IC, Minozzo JC. The efficacy of antivenom in loxoscelism treatment. Toxicon. 2006 Aug;48(2):123-37. Epub 2006 Jun 30. PMID: 16808942. https://doi.org/10.1016/j.toxicon.2006.05.005
• Ratcliffe BC. A case of tarantula-induced papular dermatitis. J Med Entomol. 1977 Jun 20;13(6):745-7. PMID: 886567. https://doi.org/10.1093/jmedent/13.6.745
• Rauber A. Black widow spider bites. J Toxicol Clin Toxicol. 1983-1984;21(4-5):473-85. PMID: 6381753. https://doi.org/10.3109/15563658308990435
• Rosen JL, Dumitru JK, Langley EW, Meade Olivier CA. Emergency department death from systemic loxoscelism. Ann Emerg Med. 2012 Oct;60(4):439-41. Epub 2012 Feb 2. PMID: 22305333. https://doi.org/10.1016/j.annemergmed.2011.12.011
• Ryan NM, Buckley NA, Graudins A. Treatments for Latrodectism-A Systematic Review on Their Clinical Effectiveness. Toxins (Basel). 2017 Apr 21;9(4):148. PMID: 28430165; PMCID: PMC5408222. https://doi.org/10.3390/toxins9040148
• Sams HH, Dunnick CA, Smith ML, King LE Jr. Necrotic arachnidism. J Am Acad Dermatol. 2001a Apr;44(4):561-73; quiz 573-6. PMID: 11260528. https://doi.org/10.1067/mjd.2001.112385
• Sams HH, Hearth SB, Long LL, Wilson DC, Sanders DH, King LE Jr. Nineteen documented cases of Loxosceles reclusa envenomation. J Am Acad Dermatol. 2001b Apr;44(4):603-8. PMID: 11260533. https://doi.org/10.1067/mjd.2001.112380
• Stanford CF, Bush SP, Clark RF, et al A new Fab2 antivenom for widow spider envenomation (Latrodectism). Clin Toxicol 2007; 45: 619.
• Stulting RD, Hooper RJ, Cavanagh HD. Ocular injury caused by tarantula hairs. Am J Ophthalmol. 1983 Jul;96(1):118-9. PMID: 6869472. https://doi.org/10.1016/0002-9394(83)90475-0
• Sutherland SK. Antivenom use in Australia. Premedication, adverse reactions and the use of venom detection kits. Med J Aust. 1992 Dec 7-21;157(11-12):734-9. PMID: 1360618.
• Sutherland SK, Duncan AW. New first-aid measures for envenomation: with special reference to bites by the Sydney funnel-web spider (Atrax robustus). Med J Aust. 1980 Apr 19;1(8):378-9. PMID: 6771503.
• Sutherland SK, Tibballs J. Australian Animal Toxins. The Creatures, their Toxins and Care of the Poisoned Patient. 2nd ed. Melbourne: Oxford University Press; 2001. ISBN 0-19-550643-X
• Swanson DL, Vetter RS. Bites of brown recluse spiders and suspected necrotic arachnidism. N Engl J Med. 2005 Feb 17;352(7):700-7. PMID: 15716564. https://doi.org/10.1056/nejmra041184
• Vance M, Curry S, Gerkin R, et al. The "target lesion:" A pathognomonic sign of black widow spider (Latrodectus spp) envenomation. Vet Hum Toxicol 1986; 28: 485-486.
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• Vetter RS, Isbister GK, Bush SP, Boutin LJ. Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis? Am J Trop Med Hyg. 2006 Jun;74(6):1043-8. PMID: 16760517.
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• Wasserman GS, Anderson PC. Loxoscelism and necrotic arachnidism. J Toxicol Clin Toxicol. 1983-1984;21(4-5):451-72. PMID: 6381752. https://doi.org/10.3109/15563658308990434

Regional advice / guidelines

Australia

• Snakebite and Spiderbite. Government of South Australia. SA Health (2018)

Species-specific evidence

With spider bites, identification of the spider that caused the bite is particularly difficult.

If the spider is not brought in for identification, then identification on the basis of the patient's description is highly questionable. If the spidetr is available for identification, it is possible in most cases to achieve a conclusive result if identification is performed by an expert. Clinical data from the literature cannot be related to a conclusively identified species in many cases. The clinical information available comes from bites caused by various spider species, and it may be that the individual specimens were reliably identified, identified according to unclear criteria or not identified at all. Indirect criteria, such as a course of envenoming considered typical for a particular species of spider, and geographical criteria are often used to aid in identification.

The published studies mirror the limitations, however, still provide a valuable picture of spiders envenoming in the various parts of the world.

Atrax sp. and Hadronyche sp.

Australia

Review

• Isbister et al. (2005)

Cases reports

• Diekmann et al. (1989) 
  3 Hadronyche sp. bites. Identification: H. versuta 1/3, H. infensa 1/3, H. cerberea 1/3.

• Fisher et al. (1980) 
  2 Atrax sp. bites. Identification: A. robustus 2/2.

• Harrington et al. (1999) 
  5 cases of Hadronyche sp. bites. Identification: morphological (H. infensa; 3/5 male, 2/5 female).

• Hartman and Sutherland (1984)
  9 Atrax sp. bites. Identification: A. robustus 6/9, A. formidabilis (= Hadronyche formidabilis) 2/9, A. bermagui (?species unkown) 1/9.

• Miller et al. (2000) 
  5 cases of Hadronyche sp. bites. Identification: morphological (male H. cerberea 2/5, male H. formidabilis 1/5), male H. infensa 1/5, male Hadronyche sp. 1/5).

• Sutherland (1992)
  3 Funnel-web spider bites. Identification: A. robustus 1/3, H. cerberea 1/3, Atrax sp. 1/3.

Latrodectus sp.

Australia

Latrodectus hasselti

• Ellis et al. (2005)

• Isbister and Gray (2002) 
  56 Latrodectus hasselti bites (prospective cohort study of 750 definite spider bites with expert spider identification: 44/750 significant effects, including 37/56 Latrodectus hasselti bites). Identification: Spider collected and expertly identified.

• Isbister and Gray (2003a)
  Prospective study
  68 people with definite redback spider bites in which the spider was immediately collected and expertly identified.

• Isbister et al. (2008) 
  Randomised controlled trial of intramuscular vs. intravenous antivenom for latrodectism--the RAVE study.

• Sunterland and Trinca (1978) 
  2,144 spider bites. Method: questionnaire that was included with antivenom vials and sent in by treating doctors. Identification: attributed to L. hasselti; 20% of the cases were insufficiently documented. Over 95% of patients received antivenom. This was observed to alter the course of envenoming.

• Wiener (1961) 
  167 spider bites. Method: questionnaire given to doctors. Identification: attributed to L. hasselti.

South Africa

Latrodectus indistinctus / Latrodectus geometricus

• La Grange (1990) 
  1 case. Identification: spider brought in, L. indistinctus.

• Rayner (1987) 
  1 case. Identification: spider brought in (L. indistinctus).

• Müller (1993) 
  45 spider bites. Identification: L. indistinctus brought in and identified 6/30; indirect: typical signs and symptoms of Latrodectus envenoming that were severe enough to indicate administration of antivenom, plus improvement of the symptoms 6–12 h after antivenom administration. L. geometricus brought in and identified 10/15; satisfactory description by the patient 5/15.

USA

Latrodectus sp.

• Clark et al. (1992) 
  163 Latrodectus sp. bites (retrospective chart review). Inclusion criteria: either a positive black widow spider identification or a visible envenomation site ("target lesion"). Depending on the clinical presentation, patients were categorized as grade 1, 2, or 3 in severity.

Loxosceles sp.

Brazil

• de Souza et al. (2007)1 Loxosceles sp. bite; Identificatiom: The patient brought the spider with him, which was identified as Loxosceles species.

Brazil

Loxosceles gaucho

• Cordoso et al. (1990) 
  2 L. gaucho bites. Identification: detection of venom antigen (ELISA) from tissue fluid in the region of the bite.

Chile

Loxosceles laeta

• Schenone et al. (1989) 
  216 spider bites. Identification: spider brought in and identified as L. laeta (10%); 60% of patients saw a spider as a possible cause, 40% did not see the cause of the bite and the cause was inferred from the course of envenoming. Retrospective study.

USA

Loxosceles reclusa

• DiPaola et al. (2022)

• Hart et al. (2025)

•  Laxton and Whetstone (2024)

• McDade et al. (2010)

• Sams et al. (2001a)  

• Sams et al. (2001b)
  19 L. reclusa bites. Identification: spiders brought in by the patients and conclusively identified and clinically characteristic lesion, and typical clinical course.

•  Rosen et al. (2012)

•  Stoecker et al. (2006)

•  link Spider Research | Department of Entomology (USA)

Review

Loxosceles rufescens

Nentwig et al. (2017)

Israel

Loxosceles rufescens

• Efrati (1969) 
  1 L. rufescens bite. Identification: the spider was brought in by the patient and conclusively identified.

France

Loxosceles rufescens

• Rubinstein et al. (2016) 
  1 case; “The spider retrieved by the patient’s family, identified as Loxosceles rufescens male”.

Phoneutria sp.

Brazil

Phoneutria sp.

• Bucaretchi et al. (2000) 
  421 patients; retrospective hospital record study; Identification: “In all cases, the offending spider was identified as belonging to the genus Phoneutria.”

Phoneutria nigriventer

• Bucaretchi et al. (2008) 
  1 bite; Identification: morphological

Phoneutria sp.

• Coelho and Gonçalves (1993) 
  68 Phoneutria sp. bites. Identification: spiders brought in and identified. Average time between the bite and arriving at the hospital 1.5 h.

Various labidognath spiders

Lycosidae sp.

Brazil

• Ribeiro et al. (1990) 
  515 Lycosa bites. Identification: spiders were brought in and identified.

• Cambell et al. (1987)
  2 Lycosa bites. Identification: spiders were brought in and identified.

Clubionidae

Chiracanthium sp.

Australia / USA

Case reports and review of the international literature

• Vetter et al. (2006)
  20 cases Australia / US; 39 cases (international literature); Identification: “verified bites”.

Chiracantthium japonicum

Japan

• Ori (1975) 
  5 Chiracanthium japonicum bites. Identification: spiders were brought in and identified.

Chiracanthium mildei, Chiracanthium inclusum

USA

• Krinsky (1987)
  1 Chiracanthium mildei bite. Identification: spider was brought in and identified.

• Minton (1972) 
  1 Chiracanthium mildei bite. Identification: spider was brought in and identified.

• Furman and Reeves (1957)
  1 Chiracanthium inclusum bite. Identification: spider was identified.

• Gorham and Rheney (1968)1 Chiracanthium inclusum bite. Identification: spider was brought in and identified.

Chiracanthium punctorium

Europe

• Willamowski and Benter (2017) 
  1 bite. Identification: morphological.

• Habermehl and Mebs (1979) 8 C. punctorium bites.

• Maretic (1975) 
  21 C. punctorium bites.

• Papini (2012) 
  1 C. punctorium bite. Identification: morphological

Araneidae sp.

Europe

• Maretić and Milina  (1976) 
  1 Aranea sexpunctata bite. Identification: the partly squashed spider could be conclusively identified. Local pain. In this isolated case symptoms of envenoming similar to those caused by a Latrodectus bite were described.

Salticidae sp.

USA

• Russell (1970) 
  1 Phidippus formosus (= P. johnsoni) bite. Identification: identification of the spider from a photograph.  

Sparassidae sp.

Australia

Isbister and Hirst (2003) 

Steatoda sp.

Australia

• Isbister and Gray (2003b) 
  23 bites; Identification: morphological

UK

• Warell et al. (1991) 
  1 case: Identification: morphological.

Various mygalomorph spiders (Bird spiders and bird spider-like species)

Bites

• Ahmed et al (2009) 
  3 bites. Identification: Lampropelma nigerrimum, Pterinochilus murinus, Poecilotheria regalis.

•  Cooke et al. (1972)

Urticating hair contact

• Chang et al (1991) 
  Theraphosidae  

Theraphosidae bites and urticating hair contact

Bites

• Isbister et al. (2003b)
  9 Theraphosidae bites (Phlogielus sp. 6/9, Selenocosmia sp. 3/9); 7 bites in dogs. Identification: morphological.

• Schmidt (1989) 
  7 bites. Identification: Poecilotheria fasciata 3/7, Pterinochilus sp. 1/7, Euathlus vagans 1/7, Rhechosticta saltator 1/7, Psalmopoeus cambridgei 1/7.

Urticating hair contact

• Hered et al. (1988)
  Theraphosidae urticating hair contact. Identification: Brachypelma smithi.
• Racliffe (1977)
  Theraphosidae urticating hair contact.

• Stulting et al. (1983)
  Theraphosidae urticating hair contact (eyes).

References

• Ahmed N, Pinkham M, Warrell DA. Symptom in search of a toxin: muscle spasms following bites by Old World tarantula spiders (Lampropelma nigerrimum, Pterinochilus murinus, Poecilotheria regalis) with review. QJM. 2009 Dec;102(12):851-7. Erratum in: QJM. 2010 Mar;103(3):203-4. PMID: 19776152. https://doi.org/10.1093/qjmed/hcp128
• Bucaretchi F, Deus Reinaldo CR, Hyslop S, Madureira PR, De Capitani EM, Vieira RJ. A clinico-epidemiological study of bites by spiders of the genus Phoneutria. Rev Inst Med Trop Sao Paulo. 2000 Jan-Feb;42(1):17-21. PMID: 10742722.
• Bucaretchi F, Mello SM, Vieira RJ, Mamoni RL, Blotta MH, Antunes E, Hyslop S. Systemic envenomation caused by the wandering spider Phoneutria nigriventer, with quantification of circulating venom. Clin Toxicol (Phila). 2008 Nov;46(9):885-9. PMID: 18788004. https://doi.org/10.1080/15563650802258524
• Campbell DS, Rees RS, King LE. Wolf spider bites. Cutis. 1987 Feb;39(2):113-4. PMID: 3829717.
• Cardoso JL, Wen FH, França FO, Warrell DA, Theakston RD. Detection by enzyme immunoassay of Loxosceles gaucho venom in necrotic skin lesions caused by spider bites in Brazil. Trans R Soc Trop Med Hyg. 1990 Jul-Aug;84(4):608-9. PMID: 2091365. https://doi.org/10.1016/0035-9203(90)90058-m
• Chang PC, Soong HK, Barnett JM. Corneal penetration by tarantula hairs. Br J Ophthalmol. 1991 Apr;75(4):253-4. PMCID: PMC1042338. https://doi.org/10.1136/bjo.75.4.253-b
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• Spider Research | Department of Entomology (USA)
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