Diagnosis & Treatment
At particular risk are: children, elderly people, patients with pre-existing conditions, such as coronary heart disease, arterial hypertension, lung disease, kidney disease, allergies (sensitisation) and patients taking particular drugs, such as beta-blockers.
Is it likely that a clinically relevant injection of venom has taken place?
- time of the bite,
- local pain,
- nausea, vomiting.
- state of consciousness (restlessness, sleepiness, coma).
- blood pressure/pulse,
- breathing (respiratory rate).
- local swelling,
- local redness,
- eyes (contact with urticating hairs): conjunctivitis, keratitis, iritis, chorioretinitis.
- increased bronchial secretion,
- abdominal pain, board-like abdominal rigidity (differential diagnosis acute abdomen)
- bradycardia/tachycardia/cardiac arrhythmia,
- arterial hypotension/hypertension,
- clinical signs of pulmonary oedema,
- clinical signs of shock,
- generalised muscle pain and cramps,
- muscle weakness.
Record and measure:
- blood sugar.
Exclusion of a clinically relevant systemic reaction
Monitoring for signs and symptoms of systemic envenoming (see above) for 12–24 h.
Who requires antivenom?
Patients with signs of systemic envenoming (see above "Is it likely that a clinically relevant injection of venom has taken place?" and Comments below).
How are antivenoms administered and complications caused by antivenoms treated?
Symptomatic emergency medical treatment and antivenom treatment are complementary strategies.
The aim of antivenom treatment is neutralisation of the venom.
The success of antivenom treatment depends on the quality of the antivenom, the specific properties of those venom components relevant to envenoming and the time point at which antivenom is administered.
Assessment of the importance of antivenom in the treatment of spider bites:
Spiders that cause neurological effects (neurotoxic araneism: Atrax sp., Latrodectus sp., Phoneutria sp.): antivenom has been used with success (Sutherland 1992, Dieckman et al. 1989, Hartman and Sutherland 1984, Maretic 1983, Müller 1993, Warrell 2010).
Spiders that cause local effects (necrotic araneism: Loxosceles sp.): for purely practical reasons, antivenom treatment has little significance in this situation, as patients often only seek medical help many hours after the bite. According to experimental investigations antivenom has no influence on the necrotisation process at this time point (Futrell 1992, Lucas 1988, Warrell 2010).
2. Respiratory disturbances
Early endotracheal intubation, suctioning of bronchial secretions and artificial respiration.
3. Cardiovascular disturbances with severe arterial hypertension, hypovolaemia, pulmonary oedema and shock
2. Bite wound, including the surrounding reaction, contact with urticating hairs (eyes)
- Assessment of the wound according to the usual criteria,
- split lamp.
- Cleaning, disinfection and dressing of the wound at regular intervals, immobilisation of the extremity with a splint;
- if necessary, antibiotic treatment;
- treatment of eye injuries.