Cystic fibrosis in blacks in Washington, DC: fifteen years' experience.

Controversies exist regarding the clinical presentation and characteristics of cystic fibrosis (CF) in American blacks. Between 1971 and 1986, 188 patients with CF (165 whites, 20 blacks, and 3 others) seen at Children's Hospital National Medical Center, Washington, DC, were evaluated for age at diagnosis, duration of symptoms prior to diagnosis, clinical presentations, initial sputum culture results, and weight and height at diagnosis. Comparisons between black and white patients revealed no statistically significant differences in average age at diagnosis, average duration of symptoms prior to diagnosis, average sweat electrolyte concentrations, or sputum culture results. A breakdown of presenting symptoms by race showed some points of disparity. About twice as many black patients as white patients (40% v 22%) presented with only pulmonary symptoms, whereas slightly more whites presented with only gastrointestinal symptoms (46% v 35%). Those patients presenting with a combination of symptomatology were equally distributed by race (25% black, 21% white). At diagnosis, age-adjusted weight percentiles were significantly lower for black patients than for white patients (chi 2 = 9.60, P less than or equal to 0.05). Although the authors agree that CF is relatively rare among blacks, a high index of suspicion is essential for early diagnosis.