Persistent cough in an adolescent

Jessica, a 14-year-old girl with a history of asthma, went to her pediatrician's office because of a persistent cough. She had been coughing for at least 3 months with occasional cough-free periods of less than a few days. The cough was nonproductive and was not accompanied by fever, rhinorrhea, or facial or chest pain. Jessica and her mother observed that the cough increased with exercise and typically was not present during sleep. She has used two metered-dose inhalers--albuterol and cromolyn--without any change in the cough pattern. For the past 5 years, Jessica has had mild asthma responsive to albuterol. She enjoys running on the cross-country team, soccer, and dancing. She is an average student and denies any change in academic performance. She has never been hospitalized or had an emergency department visit for asthma or pneumonia. There has been no recent travel or exposure to a person with a chronic productive cough, tobacco smoke, or a live-in pet. Jessica lives with her mother and younger sister in a 10-year-old, carpeted apartment without any evidence of mold or recent renovation. In the process of taking the history, the pediatrician noticed that Jessica coughed intermittently, with two or three coughs during each episode. At times, the cough was harsh; at other times, it was a quiet cough, as if she were clearing her throat. She was cooperative, without overt anxiety or respiratory distress. After a complete physical examination with normal findings, the pediatrician interviewed Jessica and her mother alone. Jessica's parents had been divorced for the past 6 years. She lived with her mother but visited her father, and his new family with two young children, every weekend. She spoke about this arrangement comfortably and said that she loved her father and mother but didn't like the tension she experienced at her father's home. "I don't like adults arguing when kids are around." When asked why she thought the cough persisted so long, she commented in a neutral tone, "I don't know. It's never been like this before." Jessica's pediatrician prescribed an inhaled steroid with the albuterol. When the cough did not respond after 1 week, he ordered a chest radiograph (normal) and a tuberculin skin test (purified protein derivative-negative), and he added montelukast (a leukotriene inhibitor) and monitored airway resistance with a peak flow meter. The cough persisted, and the peak flow recording showed normal airway resistance. At this time, Jessica's pediatrician suspected a conversion reaction and contemplated the next best therapeutic strategy.