Improvement of cystic fibrosis during treatment with isotretinoin

A 15-year-old boy with a history significant for multiple respiratory infections since birth presented for evaluation of acne vulgaris. He was initially prescribed doxycycline, topical tretinoin, and topical clindamycin solution, with the later addition of a benzoyl peroxide preparation to his regimen. The patient returned 6 months later after having been diagnosed with CF (cystic fibrosis) by sweat testing and genetic testing. His skin condition had not responded adequately to prior therapy, so all acne medications were discontinued. The 84-kg patient was started on 80 mg (0.95 mg/kg/d) of isotretinoin (13-cis-retinoic acid) daily. The patient's dose was decreased to 40 mg/d 2 weeks later following an episode of blood in his stool and epistaxis. At the 1- and 2-month follow-up visits, the patient reported improvement in his acne and mentioned that his lung secretions seemed reduced. His acne cleared after 4 months of therapy, so the isotretinoin was discontinued. The patient and his mother noted that no respiratory infections had occurred during the course of therapy. The patient's acne relapsed nearly 2 years later, so isotretinoin was restarted at 60 mg/d. During the next 7 months while on the drug, he experienced no further episodes of epistaxis or bloody stools and his acne had resolved by the end of therapy. The patient and his mother again reported fewer bronchopulmonary secretions and no infections requiring antibiotics during treatment with isotretinoin. This was unusual because he had experienced numerous respiratory infections requiring antibiotics during the prior 2 years. Since discontinuing the drug, the patient has had intermittent pulmonary infections and exacerbations in the symptomatology of his CF.