Cystic Fibrosis in Young Adults: An Overlooked Diagnosis, with Emphasis on Pulmonary Function and Radiological Patterns

Abstract

The adult or latent form of cystic fibrosis is not as uncommon as previously considered. This report presents and reviews five cases in which the disease was diagnosed after the age of 15 years. Respiratory symptoms, sinusitis, elevated sweat electrolytes, clubbing of the digits, impaired pulmonary function, and characteristic x-ray findings are the outstanding features of the disease. Pulmonary function studies in adult cystic fibrosis show combinations of obstructive and restrictive ventilatory impairment, elevated residual volume, impairment of ventilation perfusion relationships, and normal resting diffusing capacity. Chest x-ray films show predominantly upper-lobe involvement with patchy, linear, or nodular infiltrations perifocal emphysema, localized atelectasis; bronchograms show localized bronchiectatic changes. Awareness of this entity, early diagnosis and physiologic therapy are essential in the prevention of progressive pulmonary disability.