Beretta (2011) Swimming pool-induced asthma

A 13-year-old elite swimmer presented with wheezing after indoor swimming training. On the basis of her clinical history and the tests performed, exercise-induced asthma and mold-induced asthma were ruled out and a diagnosis of chlorine-induced asthma was made.


J Investig Allergol Clin Immunol 2011; Vol. 21(3): 240-241
2011 Esmon Publicidad
Swimming PoolInduced Asthma
S Beretta, T Vivaldo, M Morelli, P Carlucci, GV Zuccotti
Department of Pediatrics, L. Sacco Hospital, University of Milan, Milan, Italy
A 13-year-old elite swimmer presented with wheezing after indoor swimming training. On the basis of her clinical history and th e tests
performed, exercise-induced asthma and mold-induced asthma were ruled out and a di\agnosis of chlorine-induced asthma was made.
Key words: Chlorine. Asthma. Children.
Chlorination, the most commonly used method for ensuring
water hygiene in swimming pools, has potentially harmful
effects on the respiratory tract and could play a role in the rising
numbers of children and adolescents with asthma. We report
the case of an adolescent girl with chlorine-induced asthma.
Case Description
A 13-year-old white girl attended the emergency room with
dyspnea, wheezing, paresthesia, and chest pain after 2 hours of
indoor swimming training. The patient denied fever and u-like
symptoms. She had a history of hay fever without asthma, but
no history of heart disease. She had been training in indoor
swimming pools as a competitive swimmer 3 times a week
since the age of 6, and was a nonsmoker. Physical examination
revealed mild respiratory distress, and chest examination
revealed tachypnea and mild diffuse wheezing. The results of
cardiac, neurological, and musculoskeletal examinations were
normal. Arterial blood pressure was 11560 mmHg, peripheral
oxygen saturation breathing room air was 95%, and arterial
blood gas evaluation revealed a pH of 7.44, P
CO2 of 35 mmHg,
and P
O2 of 80 mmHg. The results of blood tests were negative.
Una nadadora de lite de 13 aos de edad re ri sibilancias tras un entrenamiento de natacin en una piscina cubierta. Basndo se en sus
antecedentes y en las pruebas realizadas, se descart el asma inducida por el ejercicio fsico y por moho y\ se diagnostic asma inducida
por cloro.
Palabras clave: Cloro. Asma. Nios.
Bronchoconstriction diminished after inhalation of 400
g of
salbutamol. The patient was discharged with a presumptive
diagnosis of hyperventilation syndrome, exercise-induced
asthma, andor mold-induced asthma. We prescribed 400
of salbutamol 20 minutes before every training session. Despite prophylactic treatment with salbutamol, the patient
presented a few days later with dyspnea and wheezing that,
once again, had occurred during her training session at an
indoor pool. We decided to perform routine skin prick tests with
inhalant allergens, as well as basic and exercise spirometry
in the outpatient department. These tests were performed
under normal conditions and did not reveal obstructive
pulmonary disease. The skin prick tests con rmed her known
grass and tree pollen allergy and ruled out sensitization to
epithelia, house dust mite, and, especially, mold, which could
be present in indoor swimming pools and responsible for
bronchoconstriction. Evidence from her clinical history and the
tests performed enabled us to rule out exercise-induced asthma
and mold-induced asthma; therefore, we assumed that her
bronchoconstriction was chlorine-induced. We recommended
training in a nonchlorinated swimming pool. At her follow-up
evaluation, 2 months after she had switched to a nonchlorinated
swimming pool, the patient did not report any wheezing during
her training sessions.

J Investig Allergol Clin Immunol 2011; Vol. 21(3): 240-241 2011 Esmon Publicidad
S Beretta, et al
Swimming is often recommended to children as a sport with
a low potential for exercise-induced asthma, since the humid
environment of the swimming pool is considered to protect
against exercise-induced bronchoconstriction 1,2. However,
in the last few years, the effects of chronic lung exposure to
chlorine and its byproducts have aroused increasing interest.
Chlorination, the most commonly used method for ensuring
water hygiene in swimming pools, is potentially harmful to the
respiratory tract. Irritant gases and aerosols contaminating the
air of indoor swimming pools, chlorination products present in
pool water, or even aerosols and vapors oating at the surface
of outdoor pools can affect the pulmonary epithelium and
increase asthma risk in children and adolescents 3,4. The
immediate effects of chlorine gas toxicity include in ammation
of the conjunctiva, nose, pharynx, larynx, trachea, and bronchi.
Irritation of airway mucosa leads to local edema secondary to
active arterial and capillary hyperemia and congestion, without
mast cell degranulation 5. Continued exposure seems to
produce effects further into the respiratory system, to the extent
that the structure and integrity of bronchioles and alveoli may
be lost. These changes manifest as a loss of respiratory function
due to obstruction 6. The pool chlorine hypothesis has been
postulated, that is, increasing exposure to the harmful by-
products of chlorination might contribute to the rising numbers
of children with asthma 7,8. Different studies have con rmed
the detrimental effects of pool chlorine on the respiratory tract
9-11, and attending chlorinated pools during childhood can
increase the risk of atopic diseases (asthma, allergic rhinitis,
and hay fever) 7,12,13. Few studies con rm or challenge the
pool chlorine hypothesis, and there is only 1 report that children
living in a home cleaned with chlorine bleach had a lower
prevalence of asthma 14. Nevertheless, we must remember
that children are in direct contact with the chlorinated products
(eg, gases, aerosols, water). A study involving adolescent elite
swimmers in Scotland assessed the combined effect of chlorine
and exercise on the airways, but did not reveal involvement of
surrogate markers of in ammation 15.
Although noninvasive and speci c tests to characterize the
irritating effects of chlorine on the airways are not available,
our patient bene ted enormously from avoiding a chlorinated
swimming pool.
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Y, Tanaka H, Tanaka M, Shindo M. Effects of swimming training
on aerobic capacity and exercise induced bronchoconstriction
in children with bronchial asthma. Thorax. 1999;54:196-201.
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Bernard E, Boulet LP, Ernst P. The determinance of prevalence
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chlorinated swimming pool attendance on the respiratory
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13. Helenius I, Rytil P, Metso T, Haahtela T, Venge P, Tikkanen HO.
Respiratory symptoms, bronchial responsiveness, and cellular
characteristics of induced sputum in elite swimmers. Allergy.
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chlorine bleach and the risks of allergic and respiratory diseases
in children. Pediatr Allergy Immunol. 2006;18:27-35.
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Manuscript received July 6, 2010; accepted for
publication September 22, 2010.
Dr Silvia Beretta
Clinica Pediatrica, Universit degli Studi di Milano
L. Sacco Hospital
Via GB Grassi 74
20157 Milano, Italy

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