Nairobi fly (Paederus) dermatitis in South Sudan: a case report

A 28-year-old nursing student working in Juba, South Sudan, suddenly developed a rash over her mid-right clavicle. Beginning as a 10-cm-diameter erythematous patch with an irregular border, within 24 hours it had developed an increasingly gray, necrotic center, appearing similar to a burn. The patient was seen by 2 local physicians without a diagnosis being made. Ultimately, it was diagnosed as being caused by the toxic hemolymph, pederin, from the Nairobi fly (Paederus). The rash usually affects body parts not covered by clothing; healing time ranges from 7 to 28 days, usually with permanent skin discoloration. Preventive measures include typical antivector precautions, including bed nets, long-sleeve clothing, and avoiding fluorescent lights. If the beetles are found on the skin, brushing them off, rather than crushing them, avoids producing dermatitis. Treatment includes rapidly washing the affected area, applying cold, wet compresses, and possibly treating with antibiotics, steroids, and antihistamines.