Cystic fibrosis survival rates. The influences of allergy and Pseudomonas aeruginosa.

Allergy and chronic Pseudomonas aeruginosa (PA) infection are two factors that possibly affect the clinical severity of cystic fibrosis pulmonary disease, although the role of allergy is controversial. We have examined the effects of these factors on actuarial survival rates in 117 children with cystic fibrosis who were skin tested in 1974 and classified as allergic (A+) or nonallergic (A-) by their reactions to 12 prick tests with common environmental allergens. Patients were also classified according to whether or not they had chronic pulmonary infection with PA in 1974 (PA-positive or PA-negative). Survival rates in A+ patients were not significantly different from those in the A- group (percent survival to age 16 years, 67% vs 80%), whereas the PA+ group had significantly worse survival rates than the PA- group (percent survival to age 16 years, 53% vs 84%). There was no significant interaction between allergic skin reactions and either age at onset of chronic PA infection or subsequent duration of survival.