Persistent facial edema due to spider bite: a case of edematous cutaneous loxoscelism.

Background: The bite of spiders of the Loxosceles genus causes loxoscelism. It can occur in cutaneous-necrotic, cutaneous-visceral, or predominantly edematous cutaneous loxoscelism forms. This last form is a rare variant characterized by edema without necrosis with a frequency of 5% of all cases of loxoscelism.

Clinical case: A 6-year-old girl presented edema in the eyelid that progressively increased and spread to the entire face. The relative reported that this event occurred after a spider bite. Physical examination revealed a bite-type lesion on the lower left eyelid, generalized edema throughout the face, and dysphonia. The tests showed elevated creatinine and bilirubin; the rest were normal. Initially, she received corticosteroids, antihistamines, and adrenaline. Due to the persistence of edema, we administrated anti-loxosceles serum and continued with corticosteroids and antibiotics. After 48 hours, edema decreased, and on the seventh day, it was almost entirely resolved, so the patient was discharged without complications.

Conclusions: Predominantly edematous cutaneous loxoscelism is a rare variant. It can mimic other diseases like cellulitis or anaphylaxis in the emergency room. Supportive treatment is essential to avoid complications in children.