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Emergency Flowchart

Signs and symptoms1   Emergency medical treatment   Region   Possible culprit   Antivenom
         
 

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.

Neuromuscular dysfunction
Muscle fasciculations and spasms, local and generalised (Atrax sp. and Hadronyche sp.).
Abdominal rigidity, simulating acute abdomen (L. indistinctis, L. mactans).

     

Species-specific envenoming patterns and clinical management

in

'Clinical entries: Spiders' 

   Southeast Australia   Atrax sp.
Hadronyche sp.
 

'Antivenom'2

in

'Clinical entries: Spiders' 
  Worldwide   Latrodectus sp.
 
  South America  

 Phoneutria sp.

  
  Europe  

Various other lapidognath spiders

    
         

Necrotic loxoscelism
Severe local pain and local swelling within 2–8 h after the bite;
local cyanosis within 12–24 h;
blister formation, possibly haemorrhagic;
necrosis within 24–48 h

Cutaneous-haemolytic loxoscelism
Haematological effects 
Presentation of patients with systemic envenoming is with fever, malaise, vomiting, headache, rash and jaundice 
Haemolysis
Haemolysis appears to occur rapidly or with a long delay after the bite (24–72 h to 2–3 days) 

  

Species-specific envenoming patterns and clinical management

in

'Clinical entries: Spiders' 

Skin kesion
Infiltration with local anaesthetic (xylocaine 1%, max. 0.5 ml, without the addition of a vasoconstrictor), nerve block

  

North, Central and South America; Africa to the Mediterranean

  

Loxosceles sp.

  


'Antivenom'3 
in
'Clinical entries: Spiders' 

         
Contact with urticating hairs
Eyes
Keratitis, conjunctivitis, iritis, chorioretinal scarring
Skin
Dermatitis (urticaria, papular dermatitis); itching of the skin can persist for several months		  

Species-specific envenoming patterns and clinical management

in

'Clinical entries: Spiders' 

   America  

Various mygalomorph spiders

    
         
Bite 
(Severe) pain, redness, swelling.		  

Symptomatic local treatment

If indicated
Infiltration with local anaesthetic (xylocaine 1%, max. 0.5 ml, without the addition of a vasoconstrictor), nerve block

   Worldwide   All spiders  
1 See also the Clinical flowchart as a guide to the dynamics of envenoming.
2

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.

 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.
3

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.