Seabather's eruption

Symptoms and signs

Symptoms generally arise later after showering. It is unusual to notice the eruptions immediately. Symptoms can last from a few days up to, exceptionally, two weeks.

The reaction is identified by severe itching around small red papules 1mm to 1.5 cm in size on areas of skin that were covered by water-permeable clothing or hair during ocean swimming. Initial swimmer exposure to the free-floating larvae produces no effects, as each organism possesses only a single undeveloped nematocyst which is inactive while suspended in seawater. However, due to their microscopic size and sticky bodies, large concentrations of larvae can become trapped in minute gaps between skin and clothing or hair. Once the swimmer leaves the ocean, the organisms stuck against the skin die, and automatically discharge their nematocysts when crushed, dried out, or exposed to freshwater. This is why symptoms usually do not appear until the swimmer dries, or takes a freshwater shower, without removing the affected clothing.

Treatment

Treatment is symptomatic, with most affected using a topical anti-itch cream (diphenhydramine) and a cortisone solution (hydrocortisone).

Incidence

Seabather's eruption is common throughout the range of Linuche unguiculata in the Caribbean, Florida, Mexico, and Gulf States. Cases were first identified in Brazil in 2001. The closely related Linuche aquila, found anywhere between Malaysia, the Philippines and the east coast of Africa, is also known to cause the condition.

Swimmers in Queensland, Australia, have reported seabather's eruption during the summer months of the year. Swimmers at the east-coast beaches of Auckland and the rest of the Hauraki Gulf in New Zealand can develop seabather's eruption, typically during summer.

References

References

1. (August 1993). "Seabather's eruption". N. Engl. J. Med..
2. (April 1996). "Seabather's eruption--a case of Caribbean itch". [[BMJ]].
3. (1996). "Venomous and Poisonous Marine Animals: A Medical and Biological Handbook". University of New South Wales Press.
4. (April 1993). "Clinical perspectives on seabather's eruption, also known as 'sea lice'". JAMA.
5. (26 October 2023). "Swimmer's itch. DermNet NZ".
6. (November 1995). "Seabather's eruption". South. Med. J..
7. (2001). "Seabather's eruption: report of five cases in southeast region of Brazil". Rev. Inst. Med. Trop. Sao Paulo.
8. [https://www.mdpi.com/1424-2818/13/9/420/pdf?version=1630407475 Diversity] MDPI
9. "Sea lice: What are the tiny ocean irritants?". Australian Broadcasting Corporation.
10. "Fact sheet: Jellyfish stings". Auckland Regional Public Health Service.