For many people, summer fun includes swimming -- in pools, lakes and other natural bodies of water. Unfortunately, sometimes skin bumps and other rash-like symptoms appear after recreational water exposure. These rashes are usually caused by a sensitivity to chemicals in the water, or due to a reaction from an waterborne infectious agent. While these skin bumps tend to resolve in time, see your doctor if they persist, if your symptoms are severe, or if you suspect your symptoms were caused by an allergy.
If your skin bumps appear after spending time in chlorine-treated water, such as a swimming pool or hot tub, you could have a sensitivity to chlorine. This symptoms are not an allergic reaction, but caused by irritation or contact dermatitis. This chlorine sensitivity may also cause redness, irritation, hives, and scales or crust on the skin. If you also have asthma or another airway disease, this chlorine sensitivity may also cause lung symptoms, such as coughing, breathing problems, wheezing, cold symptoms or even a tight feeling in the chest. Rinsing the skin with clear, nonchlorinated water and using topical corticosteroid or antihistamine cream often helps clear up and manage symptoms.
Swimmer's itch, also called cercarial dermatitis, causes red, raised skin bumps and sometimes blisters after swimming or wading in contaminated water. These symptoms, which can occur within minutes to days of water contact, are the result of an allergic reaction to the microscopic larvae of schistosoma flukes, after they burrow under the skin. These waterborne parasites can be found in lakes, ponds and ocean water, and are more likely to infest waters during the summer months. Since these parasites cannot develop inside a human, they die shortly after finding their way under the skin -- and symptoms tend to resolve after a week. Exposure to water contaminated by other infectious agents such as cyanobacteria, or blue-green algae, can also cause a skin rash. Treatment involves comfort measures such as bathing, cool compress, and corticosteroid or antihistamine cream.
Exposure to cold water, or cold temperatures, may cause itchy, red welts in people with cold urticaria, or cold hives. Not the same as goosebumps, a temporary skin reaction, cold urticaria leads to more severe symptoms which can last for a few hours. The exact cause is poorly understood, but this rare condition is most often triggered by water or air temperatures less than 39 degrees Fahrenheit. Treatment is geared at preventing skin exposure to cold, or your doctor may prescribe antihistamines in advance of planned exposure. Rarely, this condition can cause anaphylaxis, a life-threatening consequence of allergy.
Seek the advice of your doctor if you experience bumps on the skin after swimming. While most often these symptoms are not serious and resolve on their own, your doctor can provide advice on how to prevent and treat future occurrences. In addition, if you suspect you experienced an allergic reaction, your doctor can advise you on how to prepare for future exposures, which may lead to more serious symptoms. If you have severe symptoms, including difficulty breathing or tightness in your chest, seek immediate medical attention.
Reviewed by Kay Peck, MPH RD
- Centers for Disease Control and Prevention: Swimmer's Itch FAQs
- American College of Allergy, Asthma and Immunology: Chlorine "Allergy"
- Clinical Reviews in Allergy and Immunology: Cercarial Dermatitis, A Neglected Allergic Disease
- National Institutes of Health: Genetic and Rare Diseases Information Center: Cold Urticaria
- Washington State Department of Health: Recreational Water Illnesses