Seabather’s Eruption After Sea Exposure: A Case Report

Abstract

Seabather’s eruption is an acute pruritic dermatitis associated with exposure to cnidarians during sea bathing, particularly the thimble jellyfish Linuche unguiculata. Although this condition is frequently reported in tropical and subtropical coastal regions, information remains limited. This report describes the clinical presentation of seabather’s eruption in a 21-year-old woman after sea bathing on the northern coast of São Paulo, Brazil. Shortly after leaving the water, the patient developed an intensely pruritic papular lesion on the right upper limb, followed by additional lesions on the left wrist, the dorsum of the right hand, the right elbow, and the right popliteal fossa. Over the next five days, the papules evolved into erythematous macules, accompanied by a progressive reduction in pruritus. The patient also reported chills on the first day. Diagnosis was considered compatible with seabather’s eruption based on the temporal relationship with marine exposure, the characteristic clinical presentation, and the favorable response to symptomatic treatment. Management included topical dexamethasone and oral desloratadine, with temporary symptom relief. The lesions resolved spontaneously within approximately one week without complications. This case highlights the importance of recognizing seabather’s eruption in coastal regions, allowing appropriate symptomatic management and preventing unnecessary diagnostic procedures or treatments.