Remission of adult onset asthma is rare – a 15 year follow-up study

Background There are few long-term clinical follow-up studies of adult onset asthma.

Aim To study clinical characteristics of adult onset asthma in relation to remission and persistence of the disease in a 15-year follow-up.

Methods A cohort of 309 adults aged 20–60 years with asthma onset during the last 12 months, verified by bronchial variability, was recruited in 1995–99 from the general population in northern Sweden. The cohort was followed-up in 2003 (n=250) and 2012–14 (n=205). Structured interviews and spirometry were performed at recruitment and the follow-ups. Bronchial hyper-reactivity (BHR) and skin prick tests were performed at recruitment, and blood samples collected at the last follow-up. Remission of asthma was defined as no asthma symptoms and no use of asthma medication during the last 12 months.

Results Of eight individuals in remission in 2003, five had relapsed until 2012–14, and in total, n=23 (11%) were in remission while n=182 had persistent asthma in 2012–14. Those in remission had higher mean FEV₁ percent of predicted (pp) at recruitment than those with persistent asthma (94.6 versus 88.3, p=0.034), fewer had severe BHR (27.3% versus 50.9%, p=0.037), and they had less BMI increase (+1.6 versus +3.0, p=0.054). Of those with persistent asthma, 13% had uncontrolled asthma and they had higher levels of blood neutrophils than those with partly or controlled asthma.

Conclusion Higher FEV₁ pp and less severe BHR was associated with remission of adult onset asthma, but still, the proportion in remission in this 15-year follow-up was low.