Systemic Reaction After Centipede Bite in a Child: Diagnostic Challenges Between Toxic and Hypersensitivity Mechanisms.

BACKGROUND Centipede (Scolopendra subspinipes) envenomation typically causes localized pain and swelling and is generally considered a self-limited condition. However, systemic reactions resembling hypersensitivity responses, such as generalized urticaria and respiratory discomfort, have occasionally been reported. Differentiation of toxic venom effects from immunologically mediated reactions remains challenging, particularly in pediatric patients, because standardized diagnostic testing for centipede venom allergy is unavailable. CASE REPORT A previously healthy 4-year-old girl developed generalized urticaria, facial swelling, pallor, and transient respiratory discomfort approximately 10 minutes after sustaining multiple nocturnal centipede bites indoors. Cutaneous manifestations appeared at sites distant from the bite locations, a finding potentially compatible with a systemic reaction rather than a purely localized toxic effect. Vital signs remained stable, and symptoms improved spontaneously without pharmacologic intervention. Hymenoptera-venom-specific IgE testing performed several weeks later showed weak positivity (class 1), although the patient had no prior history of bee or wasp stings. Considering the possibility of recurrent systemic reactions in environments where repeated exposure may occur, an epinephrine auto-injector was prescribed for emergency preparedness. CONCLUSIONS This case highlights diagnostic challenges in distinguishing toxic and allergic mechanisms after arthropod envenomation in children. The persistence of venom-specific IgE beyond the acute phase may suggest susceptibility to venom-related hypersensitivity, rather than a transient response to envenomation. Even when symptoms resolve spontaneously and definitive diagnostic confirmation is unavailable, careful clinical assessment and risk stratification remain essential. Preparedness for possible future anaphylaxis should be considered when systemic symptoms occur after arthropod exposure.