Seabather's eruption is usually a benign clinical syndrome that resolves spontaneously, although severe symptoms and long-term sequelae have been identified. Recent research has implicated the larvae of a jellyfish, Linuche unguiculata, as the cause of this syndrome; confirmation by serological and experimental studies is pending. Clinical signs and symptoms are consistent with this etiology. Outbreaks occur when jellyfish larvae are transported to shore by ocean currents. Treatment is symptomatic and involves use of antihistamines and steroids.
Tomchik RS, Russell MT, Szmant AM, Black NA. Clinical Perspectives on Seabather's Eruption, Also Known as 'Sea Lice'. JAMA. 1993;269(13):1669-1672. doi:10.1001/jama.1993.03500130083037