The prevalence of asthma is approximately 5% to 10% in the general population. Of these, approximately 5% to 10% are severe asthmatics who respond poorly to asthmatic drugs, including high-dose inhaled steroids. Severe asthmatics have persistent symptoms, frequent symptom exacerbation, and severe airway obstruction even when taking high-dose inhaled steroids. The medical costs of treating severe asthmatics represent ~50% of the total healthcare costs for asthma. Risk factors for severe asthma are genetic and environmental, including many kinds of aeroallergens, beta-blockers, and anti-inflammatory drugs. Gastroesophageal reflux disease and factors such as denial, anxiety, fear, depression, socioeconomic status, and alcohol consumption can exacerbate asthma. Rhinitis and asthma usually occur together. There is increasing evidence that allergic rhinitis and rhinosinusitis may influence the clinical course of asthma. This review discusses the role of rhinosinusitis in severe asthma.
Asthma/diagnosis/drug therapy/*epidemiology ; Comorbidity ; Humans ; Prognosis ; Rhinitis/diagnosis/drug therapy/*epidemiology ; Risk Factors ; Severity of Illness Index ; Sinusitis/diagnosis/drug therapy/*epidemiology