Antigen-specific Treatment

Prior to 1900 there was already clear evidence that patients with asthma had eosinophils, Charcot-Leyden crystals and Curschmann’s spirals in their sputum. These findings left little doubt that there was an inflammatory component to this lung disease. Evidence about the role of allergens as a trigger factor for asthma was also reported in the last century, and, in 1921, Kern reported that a large proportion of patients with chronic asthma had positive skin tests to dust from their own house.