Sex Differences in Paediatric and Adult Asthma

Asthma is the most common chronic condition in Western countries. Affecting 1 in 7 children and 1 in 12 adults, asthma is responsible for >350,000 avoidable deaths every year. While most children who develop symptoms of asthma are <5 years of age, the disease is frequently misdiagnosed or not suspected in infants and toddlers. In addition, the prevalence of asthma is different in males and females throughout their lifespan. While boys are more likely to develop asthma than girls, this pattern is reversed after puberty. This indicates that sex-specific factors, such as fluctuations in hormone levels, play a role in the disease’s pathogenesis. In this review, the authors discuss recent advances in diagnostic tools for asthma in both adults and children, as well as the influences of BMI, environmental exposures, socioeconomic factors, and sex hormones in the disease’s pathogenesis. The review will show that both experimental and epidemiological evidence suggest that circulating sex hormone levels are important contributors to asthma symptoms in post-pubertal females, while their role in males and children has not been yet established. In addition, the mechanisms associated with these hormonal influences on airway inflammation and hyper-reactivity have not been yet elucidated. The authors conclude that different factors affect asthma rates and severity in children and adults, and that more research needs to be conducted to identify the specific contributions of sex hormones. These will allow the development of more personalised asthma treatment strategies for men and women at different stages of life.