Prevention of Seabather’s eruption
- Listen to local beach reports and observe posted beach messages in affected areas.
- Avoid ocean activities in areas where cases have been reported, especially during the peak season, April through July.
- Avoid wearing t-shirts while swimming. Women should consider wearing 2-piece bathing suits.These measures decrease the surface area over which larvae can be trapped. (Of course, swimmers should use potent sunscreens and carefully limit sun exposure to avoid sunburns when more skin is exposed to the sun. Some evidence suggests that the use of a sunscreen may actually protect skin from penetration by the nematocysts.)8
- Wetsuits with restrictive cuffs may be of benefit when surfing or diving.
- When swimming in areas where recent cases have occurred, change swimwear quickly after exiting the water. Do not shower with fresh water while still wearing the suit, because this may cause nematocysts trapped inside to discharge.Wash swimwear with detergent and heat-dry before wearing again. Air-dried nematocysts may still be able to fire.4,8
Diagnosis: Seabather’s eruption
Seabather’s eruption is a pruritic dermatitis that occurs predominantly on areas covered by a bathing suit or shirt after swimming in saltwater. Cases have been reported in Florida, Bermuda, the Caribbean, and as far north as Long Island, New York.
Larvae of members of the phylum Cnidaria are believed to be the cause of this dermatitis.1,2 Cnidaria include hydrozoans (fire coral and Portuguese man-of-war), scyphozoans (true jellyfish), and anthozoans (sea anemones). The condition is sometimes called sea lice, although the organisms have no relationship to lice.
All Cnidaria have microscopic envenomation capsules called nematocysts. Each capsule contains a folded, eversible tubule containing a variety of toxins. Skin contact or chemical stimulation of the triggering apparatus leads to a build-up of hydrostatic force, resulting in eversion of the tubule. Toxins pass across the tubule membrane and are deposited into the skin.