Every year more than one reader writes us about painful days on Little Cayman or misery in the Florida Keys. The problem called Sea Bather's Eruption is a nasty rash under their wetsuit or skins, leading to an itch so severe it's almost enough to drive them crazy. The season? March to August.
For decades, an old wives' tale warned Bahamians against ocean swimming between Mother's Day and Father's Day because of the nasties. Yet it wasn't until 1992 that marine biologists at the University of Miami determined that the cause was not "sea lice" but stinging cells called nematocysts, most of which come from the larva of thimble jellyfish.
The organism, which looks like a speck of finely-ground pepper, floats near the surface and gets "netted" by wetsuits, skins, and bathing suits. Friction between the apparel and the skin caused by pulling off a wetsuit, simply sitting down, or even rinsing with fresh water with your suit still on can trigger the nematocysts to fire.
It may take up to twentyfour hours to feel the first prickling sensation, which can be followed by intense itching, nausea, vomiting, diarrhea, headache, muscle spasms, a sense of malaise, and trouble sleeping.
To treat, apply an antihistamine, such diphenhydramine hydrochloride, followed by 0.5% hydrocortisone cream. DAN suggests beginning with a rinse of vinegar or rubbing alcohol and notes that calamine lotion may be soothing.
Unfortunately, the only way you'll know that the larva are present is by observing an eruption in someone else.. To make sure that first-erupting swimmer isn't you, We recommend you slip out of your swimming apparel as soon as possible, then shower off loose larvae. If you must wear your suit again, try to wash it out with detergent and heat dry it. Airdried nematocysts still have the ability to fire.
There are some practical tips from experts on how to avoid a sea lice assault
Use a water-resistant topical sunscreen. There is some evidence they may help prevent sea lice irritation
Avoid wearing T-shirts while swimming in the ocean
The smaller the bathing suit, the less likely the sea lice problems. Less fabric means less likelihood of trapping the larvae. Smooth material may also trap fewer larvae than open-weave material
Bathing suits should be removed immediately after ocean swimming
Do not rinse off while wearing a contaminated suit -- rinse yourself off after removing it
Bathing suits should be washed with hot water and detergent and dried in a hot drier
In the case of a severe reaction you should dispose of the bathing suit
Those with severe reactions should avoid ocean swimming when there are any reports of sea lice in the area
TREATMENT:
Treatment of this dermatitis currently includes the administration of an antihistamine, such diphenhydramine, for the itching and the application of an over-the-counter 0.5% hydrocortisone cream to the rash areas. Persons suffering from exteneruptions, with or without urticaria, or with recurrences of symptoms may benefit from the administration of epinepherine as well as oral or intramuscular steroids. A prescription for 1.0% corticosteroid cream can also be given.
Comfort measures include bathing in a colloidal oatmeal preparation and applying calamine lotion. The latter may be good for children, who benefit from its visual placebo effect. Diphenhydramine and calamine (Caladryl) lotion should not be applied when an oral antihistamine is being used to avoid toxic effects, especially in children. Caution is also in order, to make sure that steroid creams, in combination with oral steroids, are not overused. This may occur when large body surfaces are involved.
As noted, children with seabather's eruption tend to exhibit febrile reactions more frequently than adults, probably because of their immune response. Parents should be observant and treat the symptoms. An additional recommendation for children is to clip their fingernails short, to avoid scratching of lesions.
Good personal hygiene, especially in the perineal area, will help patients of any age to avoid secondary bacterial infections. Should a secondary infection occur, as evidenced by purulent lesions that are not resolving, follow-up care with a dermatologist is recommended.
Any rash needs a thorough evaluation to rule out possible communicable causes. The key to the diagnosis of seabather's eruption is a history of ocean exposure followed by the development of a dermatitis within 24 hours of exposure. Multiple persons within one household are typically affected. Persons with the rash of seabather's eruption are not considered contagious.
PREVENTION:
Outbreaks of seabather's eruption occur intermittently between March and August, but they appear to peak during early April through early July. There have been many days when no infestations have occurred. Beach goers need to listen to local beach reports and observe daily posted beach messages in affected areas. The following recommendations may also help in minimizing the number of stings:
Each beach goer needs to assess his or her individual risk of an immune response. Persons with a history of a severe reaction should confine their beach activities to land, or use pool facilities instead, during outbreaks.
Swimmers should avoid wearing T-shirts while in the ocean. Use of a topical sunscreen and limiting sun exposure protects against solar injury. There is some evidence that use of a topical sunscreen or suntan lotion may actually protect skin from penetration by the nematocysts.
Women should consider two-piece instead of one-piece bathing suits, to reduce the surface area of swimwear that could trap larvae. It is possible that smooth, tight weave bathing suits may trap fewer larvae than suits with an open-weave fabric.
After ocean exposure, swimmers need to change out of their bathing suits as soon as possible after exiting from the water. Most lesions have occurred from contact with contaminated swimwear. Removal of possibly contaminated swimwear, followed by a shower to rinse off loose larvae, should limit the number of stings. If showers are in a public area, it is suggested that people bring a second suit to the beach; after removing the first, possibly contaminated suit, they can don the second suit and then shower. Showering with fresh water while still wearing a contaminated bathing suit could cause discharge of nematocysts trapped in the fabric of the suit.
Bathing suits should be thoroughly washed with detergent and heat-dried after use. Some have experienced a recurrence of symptoms when wearing suits that had only been air-dried. Air-dried nematocysts still have the potential to fire. A person who has had a severe reaction may be wise to discard the infested suit.
Swim only where there are lifeguards and ask about the conditions of the water.
And this is probably more than what you want to know. lol
