Beware of Recreational Water Illnesses

Make a splash without getting sick this summer.

From the WebMD Archives

First Jaws kept millions of Americans out of the water, and now some experts fear that the rapid increase of recreational water illnesses (RWI) may do the same thing. And they caution that with the soaring rates of childhood obesity, anything that prevents kids from getting regular exercise -- including swimming -- may do more harm than good.

RWI refers to any illness or infection caused by organisms that contaminate water in pools, lakes, hot tubs, and oceans, resulting in diarrhea, skin rashes, swimmer's ear, and other conditions. And they are on the rise. The rate has more than doubled in the past 10 years, according to data from the CDC.

"No one who swims is safe from RWIs," says Alan Greene, MD, an assistant clinical professor of pediatrics at Stanford University in Stanford, Calif., and author of several books including From First Kicks to First Steps.

In the summer of 1975, Jaws had beachgoers heeding the advice of the movie's tagline, "Don't go in the water." But unlike great white sharks that may lurk below the ocean's surface, simple prevention methods as well as quick treatment can help keep RWIs at bay -- where they belong, Greene says. "Not swallowing water and drying your ears can reduce the great majority of RWIs," he says.

As with most things, the best defense is a good offense.

Know Thy Enemy

Infection-producing germs that can lurk in water include Pseudomonas aeruginosa, which causes swimmer's ear (an infection of the outer ear canal, known medically as otitis externa) and skin rash (dermatitis). Others include cryptosporidium, Giardia lamblia, shigella, and E. coli, which can cause diarrhea. Each year, 10,000 RWI cases of diarrhea and 6.2 million cases of swimmer's ear occur, according to the CDC. "You can catch respiratory illnesses and colds but by far, skin rashes, swimmer's ear, and gastrointestinal bugs are the most common," he says.

Diarrhea may occur when contaminated water is swallowed and driven into the mouth or nose, Greene explains. It may not begin immediately after a swim; sometimes it comes on one to two weeks later.


"Swimmer's ear is easier to get," he says. "Excessive water in the ear canal breaks down the protective barriers in the ear and allows bacteria to get into the ear," he explains.

It is marked by one to two days of progressive ear pain that is worsened by chewing or when the ear is being pulled. Itching, pus, and discharge often follow.

Swimmer's itch, also called cercarial dermatitis, is marked by tingling, burning, or itching of the skin, small reddish pimples, and/or small blisters that appear within minutes to days after swimming in contaminated water. This skin rash is primarily caused by exposure to parasites or their larvae in fresh and salt water. According to the CDC, hot tub rash, or dermatitis, is an infection of the skin in which the skin may become itchy and progress to a bumpy, red rash that may become tender. There may also be pus-filled blisters that are usually found surrounding hair follicles. The rash is usually caused by the bacteria Pseudomonas aeruginosa. It usually occurs within a few days of swimming in poorly maintained hot tubs or spas, but it can also be spread by swimming in a contaminated pool or lake.

An Ounce of Prevention...

Many people say that adding chlorine to a pool can kill all potentially disease-causing germs, and that's true -- to a degree. Chlorine in properly disinfected pools kills most germs that can cause RWIs in less than an hour, but it takes longer to kill some germs, such as cryptosporidium, which can survive for days in even a properly disinfected pool.

"The best way to prevent diarrhea is not to swallow water," Greene says. Also, don't swim when you have diarrhea because you can spread germs in the water and make other people sick. Take a shower before swimming and wash your hands after using the toilet or changing diapers because germs on your body end up in the water.

By contrast, risk factors for swimmer's ear may include swimming/diving; perspiration; high humidity; mechanical trauma such as removal of wax, use of cotton dabs, and fingernails; hearing aids or headphones; drying soap or shampoo; and a history eczema and psoriasis, Greene says.


The best ways to prevent it? Tilt and tug, says Greene. Put another way: "dry ears thoroughly by tilting your head to the side and tugging the ear lobe to let the water out after swimming," he explains.

Crissy Perham, a three-time Olympic medalist in swimming and now a high school coach, adds that "drying your ears out, getting ear plugs, or wearing swim caps pulled over your ears helps prevent swimmer's ear."

As a coach, "not a week goes by that I don't have one to two kids who are out of the water due to swimmer's ear, and sometimes we don't have a full squad at a meet," she says.

Showering before and after taking a dip in lakes, ponds, and oceans can help with prevention of skin rashes.

If Prevention Isn't Enough

If you have diarrhea one to two weeks after swimming, drink plenty of fluids to prevent dehydration. Antidiarrheal medicine may help, but talk to your doctor before taking it.

As for swimmer's ear, new treatment guidelines published in April 2006 suggest that antibiotic ear drops are the treatment of choice for swimmer's ear, yet up to 40% of kids with swimmer's ear get oral antibiotics instead.

But, Greene says, "they don't work, and when you give them, you give 100 to 1,000 times higher a dose then you do with the drops, and [oral antibiotics] get everywhere in the body, so you get side effects and increased bacterial resistance. There is absolutely no reason for a healthy, normal child to get oral antibiotics as first-line therapy for swimmer's ear."

Some eardrops are now available in once-a-day formulations, he says. For pain, oral medication (such as Tylenol or Motrin) can be given immediately.

Most cases of swimmer's itch do not require medical attention, but not scratching and using anti-itch cream can help. Hot tub rashes usually clear up in a few days without medical treatment.

WebMD Feature Reviewed by Louise Chang, MD on June 06, 2007


Published April 10, 2006.

SOURCES: Alan Greene, MD, assistant clinical professor of pediatrics, Stanford University, Stanford, Calif.; author, From First Kicks to First Steps. Crissy Perham, three-time Olympic medalist, high school coach. CDC web site: "Healthy Swimming."
© 2006 WebMD, Inc. All rights reserved.


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