Inhalation bronchoprovocation in children

Airway hyperresponsiveness (AHR) is a characteristic feature of asthma. The measurement of AHR in children can be useful to clarify the diagnosis of asthma, classify the severity of asthma, study the mechanisms of asthma, study drug effects, and perform epidemiologic surveys. There are a number of techniques that have been used in children to objectively measure AHR, including both pharmacologic and nonpharmacologic challenges. Methacholine and histamine are the most sensitive tests, and are probably best to diagnose asthma in the patient with suggestive historic clues. The nonpharmacologic challenges are more specific, however, and may be more appropriate for drug studies. Overall, the choice of challenge depends on the question one is attempting to answer.