Spider Bites, Neurotoxic (Button/Widow Spiders)
Description Diagnostic criteria General and supportive measures Medicine treatment DESCRIPTION The term latrodectism is used to describe the systemic symptoms and signs following envenomation by the bite of the Latrodectus species (button or widow spiders). Most cases are caused by the bite of a black button spider; brown button spider bites are usually milder and characterized by local sym
Description
Diagnostic criteria
General and supportive measures
Medicine treatment
DESCRIPTION
The term latrodectism is used to describe the systemic symptoms and signs following envenomation by the bite of the Latrodectus species (button or widow spiders). Most cases are caused by the bite of a black button spider; brown button spider bites are usually milder and characterized by local symptoms and signs.
DIAGNOSTIC CRITERIA
- Bites are felt immediately as a pinprick sensation, followed by increasing local pain that may spread to include the entire extremity.
- Typical target lesions, i.e. erythematous ring surrounding a pale centre.
- Spasms in large muscle groups, abdominal pain or rigidity, progressing to generalised pain involving the trunk and abdomen have been described.
- Paraesthesia of hands and feet.
- Sweating and anxiety may occur.
- Priapism may occur, especially in children.
GENERAL AND SUPPORTIVE MEASURES
- Supportive care of airway, breathing and circulation.
MEDICINE TREATMENT
Analgesia:
- Paracetamol, oral, 15 mg/kg/dose, 6 hourly as required.
For pain and muscle cramps:
- Calcium gluconate 10%, IV, 0.5 mL/kg by slow intravenous injection.
- Give 0.5–1 mL/minute.
- Monitor ECG and respiration.
For severe envenomation (if systemic symptoms are present):
- Latrodectus spider antivenom, IV infusion, 5–10 mL diluted in sodium chloride 0.9% or dextrose 5%, 50–100 mL administered over 5–10 minutes.
- Obtainable from South African Vaccine Producers (Tel.: +2711 386 6063/2/78 or after hours 071 680 9897 or 082 884 2971). See full details in the package insert.
CAUTION
Never administer antivenom without being prepared to manage acute anaphylaxis.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Paediatrics, 2023 Edition
Chapter 18: Poisoning, 18.2 Envenomation, 18.2.5 Spider Bites, 18.2.5.1 Spider Bites, Neurotoxic (Button/Widow Spiders)