House Dust Mite Sublingual Immunotherapy Prevents Some Asthma Exacerbations

House dust mites are the most important allergic trigger for asthma and perennial allergic rhinitis. Subcutaneous immunotherapy improves allergic rhinitis and allergic asthma and has a disease-modifying effect but comes with multiple injections and risk for systemic allergic reactions. Dust mite sublingual immunotherapy (SLIT) consists of a tablet or liquid administered daily and held under the tongue; it improves symptoms of allergic rhinitis and often results in lower required doses of inhaled corticosteroid (ICS) in asthmatic patients, but it has not been shown to prevent asthma exacerbations.

In an industry-funded European trial, 834 dust mite–allergic patients with uncontrolled asthma despite ICS treatment were randomized to lower or hi…