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Seabather's Eruption

  • Author: Clarence William Brown, Jr, MD, FAAD; Chief Editor: William D James, MD  more...
Updated: Mar 10, 2016


Seabather's eruption was first described in 1949 as a pruritic papular eruption occurring in bathers off the eastern coast of Florida. Seabather's eruption is a highly pruritic, papular eruption that occurs underneath the swimsuit after extended exposure to seawater. Seabather's eruption results from a hypersensitivity to the larval form of the thimble jellyfish, Linuche unguiculata.[1] Most cases occur from March to August, but the incidence peaks in May and June.

See Deadly Sea Envenomations, a Critical Images slideshow, to help make an accurate diagnosis.

See also the Medscape article Cutaneous Manifestations Following Exposures to Marine Life.



Seabather's eruption is a cutaneous hypersensitivity reaction to contact with the larval form (planulae) of the thimble jellyfish, L unguiculata. The eruption typically occurs underneath the bathing garments, which are believed to trap the jellyfish larvae against the skin. Whether the discharge of venom by the trapped larvae plays an important role in the pathogenesis of the eruption remains uncertain. Factors that promote the discharge of venom by the larvae include wearing of bathing suits for prolonged periods following swimming, exposure to fresh water through showering, and mechanical stimulation.




United States

The incidence of seabather's eruption is seasonal; the highest incidence occurs from May through August. This coincides with the warm gulf streams running along the Atlantic coastline of Florida and the corresponding spawn of thimble jellyfish larvae, which results in the high seasonal concentration of Linuche planulae. In 1997, Kumar et al[2] reported the occurrence of seabather's eruption in Palm Beach saltwater swimmers in May to be 16%.


Seabather's eruption has been reported in Mexico and the Caribbean and along the coast of Brasil.[3, 4]  The true prevalence of seabather's eruption along other international coastlines remains unknown.


Seabather's eruption occurs independent of race.


Seabather's eruption has been noted with equal frequency in both sexes.


No correlation between age and risk for developing seabather's eruption has been noted. The severity of symptoms, particularly the frequency of fever, is greater in children than in adults.

Contributor Information and Disclosures

Clarence William Brown, Jr, MD, FAAD Chief Executive Officer, University Dermatology

Clarence William Brown, Jr, MD, FAAD is a member of the following medical societies: American Medical Association, Chicago Medical Society, Illinois State Medical Society, Chicago Dermatological Society, Illinois Dermatological Society, American Academy of Dermatology, American College of Mohs Surgery

Disclosure: Nothing to disclose.

Specialty Editor Board

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Association of Military Dermatologists, Texas Dermatological Society

Disclosure: Nothing to disclose.

Jeffrey P Callen, MD Professor of Medicine (Dermatology), Chief, Division of Dermatology, University of Louisville School of Medicine

Jeffrey P Callen, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Physicians, American College of Rheumatology

Disclosure: Received income in an amount equal to or greater than $250 from: XOMA; Biogen/IDEC; Novartis; Janssen Biotech, Abbvie, CSL pharma<br/>Received honoraria from UpToDate for author/editor; Received honoraria from JAMA Dermatology for associate editor and intermittent author; Received royalty from Elsevier for book author/editor; Received dividends from trust accounts, but I do not control these accounts, and have directed our managers to divest pharmaceutical stocks as is fiscally prudent from Stock holdings in various trust accounts include some pharmaceutical companies and device makers for i inherited these trust accounts; for: Celgene; Pfizer; 3M; Johnson and Johnson; Merck; Abbott Laboratories; AbbVie; Procter and Gamble; Amgen.

Chief Editor

William D James, MD Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine

William D James, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Carrie L Kovarik, MD Assistant Professor of Dermatology, Dermatopathology, and Infectious Diseases, University of Pennsylvania School of Medicine

Carrie L Kovarik, MD is a member of the following medical societies: Alpha Omega Alpha

Disclosure: Nothing to disclose.

  1. Segura Puertas L, Burnett JW, Heimer de la Cotera E. The medusa stage of the coronate scyphomedusa Linuche unguiculata ('thimble jellyfish') can cause seabather's eruption. Dermatology. 1999. 198(2):171-2. [Medline].

  2. Kumar S, Hlady WG, Malecki JM. Risk factors for seabather's eruption: a prospective cohort study. Public Health Rep. 1997 Jan-Feb. 112(1):59-62. [Medline].

  3. Rossetto AL, Da Silveira FL, Morandini AC, Haddad V, Resgalla C. Seabather's Eruption: Report of Fourteen Cases. An Acad Bras Cience. March 2015. 87(1):431-6. [Medline].

  4. Rossetto AL, Proença LA. Seabather's eruption: report of case in northeast region of Brazil. An Bras Dermatol. 2012 May-Jun. 87 (3):472-4. [Medline].

  5. Freudenthal AR, Joseph PR. Seabather's eruption. N Engl J Med. 1993 Aug 19. 329(8):542-4. [Medline].

  6. Wong DE, Meinking TL, Rosen LB, Taplin D, Hogan DJ, Burnett JW. Seabather's eruption. Clinical, histologic, and immunologic features. J Am Acad Dermatol. 1994 Mar. 30(3):399-406. [Medline].

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