Table 4.

Asthma comorbidities in childhood.

Comorbid Conditions	Potential mechanism contributing to worsen asthma
Obesity	Mechanical effects on lung functions; pro-inflammatory state contributing to airway inflammation; corticosteroid resistance
Gastroesophageal reflux	Direct contamination of the lower airway; esophago-bronchial reflex; reduced efficiency of the lower esophageal sphincter due to altered configuration of the diaphragm during respiratory disease
Food allergy	Unclear (consider anaphylaxis at rest and on exercise in the differential diagnosis)
Rhinosinusitis	Shared complex inflammatory mechanisms between upper and lower airways, according to the “United Airways Disease” concept
Upper Airway Obstruction/Sleep Disordered Breathing	Obesity-associated (common); increased neutrophilic inflammation of the airways
Dysfunctional Breathing	Unclear (also consider vocal cord dysfunction and other hyperventilation syndromes in the differential diagnosis)