Seabather's eruption

Background

Normal dermal anatomy.

• Cnidaria larvae get trapped, release toxin
• Nematocysts of the larval forms of sea anemones: Edwardsiella lineata
• Thimble jellyfish: Linuche unguiculata
• Not be confused with cercarial dermatitis, which is caused by freshwater schistosomes or coastal water clam diggers

Clinical Features

Excoriated papules in areas covered by swimsuit. Box shows Linuche unguiculata, the thimble jellyfish, whose larvae and adult forms caused this dermatitis.

• Rash generally under the garments worn by bathers and swimmers (where the organisms are trapped after the person leaves the water)
  • Versus Cercarial dermatitis, which is occurs on the exposed skin outside of close-fitting garments

Differential Diagnosis

Marine toxins, envenomations, and bites

• Toxins
  • Ciguatera
  • Scombroid
  • Tetrodotoxin (e.g. pufferfish)
  • Shellfish poisoning
    • Amnesic shellfish poisoning
    • Diarrheal shellfish poisoning
    • Neurotoxic shellfish poisoning
    • Paralytic shellfish poisoning
• Stingers
  • Stingray injury
• Venomous fish
  • Cone shell
  • Lionfish
  • Sea urchins
  • Crown-of-Thorns Starfish
  • Stonefish
  • Other: Catfish, zebrafish, scorpion fish
• Nematocysts
  • Coral reef
  • Fire coral
  • Jellyfish (Cnidaria)
    • Box jellyfish
      • Irukandji syndrome
    • Sea wasp
  • Portuguese man-of-war
  • Sea anemones
  • Seabather's eruption
• Phylum porifera (sponges)
• Bites
  • Alligator and crocodile attacks
  • Octopus bite
  • Shark bite
• Infections
  • Vibrio species in saltwater
  • Aeromonas species in freshwater

Travel-related skin conditions

• Papules
  • Insect bites
  • Scabies
  • Seabather's eruption
  • Cercarial dermatitis (Swimmer's Itch)
• Macular
  • Chikungunya
• Sub Q Swelling and Nodules
  • Myiasis
  • Tungiasis
  • Loa loa
  • African Trypanosomiasis
  • Onchocerciasis
• Ulcers
  • Tropical pyoderma
  • Leishmaniasis
  • Mycobacterium marinum
  • Buruli ulcer
  • Dracunculiasis (Guinea Worm disease)
• Linear and Migratory Lesions
  • Cutaneous larvae migrans
  • Photodermatitis

See also domestic U.S. ectoparasites

Evaluation

• Typically a clinical diagnosis

Management

• Thoroughly wash and dry bathing clothes.
• Consider oral diphenhydramine for pruritis.

Disposition

• Discharge home
• Return precautions for signs of bacterial superinfection of the lesions.

See Also

• Parasitic Diseases
• Travel Medicine