Table 1.

Common phenotypes of childhood asthma

Phenotype	Onset	Natural history	Triggers	Biomarker characteristics	Treatment
Atopic	Infancy	chronic	Virus, allergen	Elevated IgE, FENO	Chronic: ICS
Virus-induced wheezing	Infancy	Resolves by school age	Virus	Normal IgE, FENO	Supportive care, bronchodilators
Exercise-induced	School age – adolescence	chronic	Exercise	IgE, eosinophils,110 cysLTs111 may be elevated; FENO typically normal112	Acute: Pretreat with bronchodilator, Chronic: montelukast, cardiopulmonary conditioning
Obesity-related	All ages, but more common in adolescence	May resolve with weight loss	Non-specific	Typically normal IgE, normal FENO	Weight loss; ICS may be less effective among obese; consider LTM

Abbreviations: IgE, Immunoglobulin E; FENO, fractional exhaled nitric oxide; ICS, inhaled corticosteroid; cysLT, cysteinyl leukotrienes (LTC4, LTD4, and LTE4); LTM, leukotriene modifier.