Background: The malmignatte Latrodectus mactans tredecimguttatus, commonly known as a black widow spider, can be found in the Mediterranean region. Its bite is a cause of a rarely seen syndrome called latrodectism.
Case report: During a visit to Corsica, a 13-year-old boy developed abrupt severe abdominal pain and spasmodic muscular contractions, headache and vomiting. The patient was restless and experienced hallucinations including distressing visions of death. His high blood pressure (154/100 mmHg) returned to normal within 3 days. Clinical examination revealed dyspnea and facial edema associated with blepharoconjunctivitis and hyperreflexia, together with a scattered erythema and pruritus. These changes took place within minutes, after a probable black widow spider bite. The abdominal and neuropsychiatric symptoms disappeared after 5 days. Treatment with calcium gluconate, paracetamol, phloroglucinol and hydroxyzine had no effect, but diazepam decreased the acuteness of the symptoms. Anti-venom serum was not used.
Conclusion: Diagnosis of latrodectism must be based on clinical and epidemiological data. Erroneously diagnosing surgical acute abdomen, renal colic, meningitis, tetanus or opioid withdrawal would entail incorrect treatment.