Increased sensitization to aeroallergens in competitive swimmers.

Chlorine is used to disinfect swimming pools or as a constituent of other disinfection reagents. Pulmonary diseases are occasionally observed after exposure to chlorine. In 14 competitive swimmers and in 14 matched control subjects, we searched for clinically manifest allergies, subclinical sensitization to aeroallergens, imbalance of the cellular immune system, and bronchial hyperresponsiveness. Conjunctival or respiratory symptoms were found in 11 swimmers (2 cases of conjunctivitis, 4 rhinitis, 2 rhinoconjunctivitis, 1 laryngitis, and 2 bronchitis) and in 3 controls. Sensitization to aeroallergens was confirmed in 9 swimmers by skin test and in 11 swimmers by radioallergosorbent test (RAST), compared to findings in 4 and 5 controls, respectively. An altered cellular immune system, (i.e., imbalance in T-cell system, B-cell system, or natural killer cells) was detected in 7 swimmers and only 2 controls. Bronchial hyperresponsiveness to methacholine was seen in 11 swimmers and 5 controls. This higher incidence of allergic diseases and subclinical sensitization to aeroallergens, disorders of the cellular immune system, and bronchial hyperresponsiveness in competitive swimmers compared with control subjects could be due to repeated exposure to chlorine in swimming pools.