SEABATHERS ERUPTION - CLINICAL, HISTOLOGIC, AND IMMUNOLOGICAL FEATURES

Background: Seabather's eruption (SE) is a highly pruritic eruption un der swimwear that occurs after bathing in the ocean. Its cause has bee n unknown. Few data have been collected since the classic description by Sams in 1949. Objective: Our purpose was to describe the clinical a nd histopathologic findings in SE and to confirm the cause. Methods: P atients with a pruritic eruption that developed after swimming were se en within 1 week of onset. Skin biopsy specimens and sera were obtaine d in selected cases. Water samples taken from areas of active SE outbr eaks were examined for a causative organism. Sera were tested by enzym e-linked immunosorbent assay for reactivity to this organism. Results: In southeast Florida, during a 4-month period, 70 patients with SE we re seen. Inflammatory papules and pruritus were noted within hours of exposure. Eruptions were maximal in areas covered by a bathing suit. C hildren were more likely than adults to have systemic symptoms. The av erage duration of the eruption and pruritus was 12.5 days, with re cur rences in 4.3% of patients. Histopathologic examination revealed a sup erficial and deep perivascular and interstitial infiltrate consisting of lymphocytes, neutrophils, and eosinophils. Water samples contained many cnidarian larvae, later grown to maturity and identified as Linuc he unguiculata (thimble jellyfish). Enzyme-linked immunosorbent assay demonstrated in patients' sera high IgG levels specific for L. unguicu lata. Conclusion: SE is a severely pruritic marine dermatosis that res olve spontaneously within 2 weeks. Therapy is symptomatic but often in effective. Sera from affected persons showed specific reactivity to L. unguiculata.