Hygienic habits are a risk factor for adult-onset asthma

Multiple etiologies have been shown to contribute to asthma development, with excessive hygiene and microbial deprivation being one of the strongest risk factors for asthma onset in pediatric populations. The present study evaluated the contribution of hygienic habits in the development of adult-onset asthma. Twenty three adult-onset asthma patients (age of onset ranged from 21 to 71 years old) and 36 controls were asked to respond to a questionnaire concerning their frequency of shower taking and hand washing. Nine of the 23 (39.1%) asthmatic patients reported taking showers twice per day, compared to 2 controls (5.6%; χ 2 = 15.4, p=0.017). In addition, sixteen (69.6%) of the asthmatic patients reported very frequent hand washing (≥ 7 times per day), whereas only 6 (16.7%) controls reported less frequent (2 – 6 times per day) hand washing habits. These data confirm that excessive hygienic habits are associated with the development of adult-onset asthma.