Limited information is available about clinical outcomes and microbiology of community-acquired pneumonia in asthma.

We prospectively studied 4079 CAP patients over a 12-years period and found 139 (3.4%) asthmatic patients.

Asthmatics showed younger age (57 ± 19 vs. 66 ± 19 years), less males (32% vs. 68%) and less active smokers (15% vs. 25%). Moreover, they had used more frequently inhaled corticosteroids (ICs, 53% vs. 17%, p < 0.001) and antibiotics (32% vs. 24%, p = 0.041). In comparison with non asthma-CAP, asthmatics showed at admission more pleuritic pain and dyspnoea but less severe pneumonia (PSI, CURB-65, PaO₂/F_IO₂ ratio; p < 0.05). No differences were observed in CAP microbiology, being Streptococcus pneumoniae the most frequent isolate. Clinical outcomes in asthmatic patients were similar to the general population (mortality, mechanical ventilation, etc.) but with a shorter median length of stay (6 [3; 9] vs. 7 [4; 10] days, p = 0.023). The chronic use of ICs did not influence clinical presentation and outcomes among asthmatic patients.

Asthmatics were younger and showed similar clinical presentation. Consistently with PSI, asthmatics showed similar outcomes than the general population. The microbial aetiology of CAP in asthma did not differ from the general population and antibiotic therapy should follow current guidelines.