While an allergy to chlorine does not exist, the chemical is a natural irritant and can exacerbate existing dermatological conditions, according to the American College of Allergy, Asthma & Immunology. Hives seemingly caused by chlorine exposure are actually irritant dermatitis due to chemical sensitivity.
Because chlorine dries out the skin, exposure to the chemical can irritate existing dermatitis, says the American College of Allergy, Asthma & Immunology. Chlorine can also irritate and sensitize the respiratory tract. An underlying case of asthma, exercise-induced bronchoconstriction or bronchospasm might be responsible for certain reactions seemingly linked to chlorine exposure. Normally those with a skin sensitivity treat the condition by using clean water to wash away any existing chlorine on the body, although a physician may prescribe a corticosteroid cream.