Histamine inhalation test is a type of bronchial drug provocation test. By nebulizing and inhaling the biologically active medium histamine, the bronchial smooth muscle is directly stimulated to contract, and at the same time, cholinergic nerve endings are also stimulated, reflexively causing smooth muscle contraction and leading to bronchospasm. Then, the degree of bronchial stenosis is determined by pulmonary function indicators to measure its reactivity.

(1) For the diagnosis of diseases with increased airway reactivity, a positive result of this test indicates the diagnosis of bronchial asthma, while a negative result rules out asthma.

(2) Evaluate the efficacy of bronchodilator drugs.

(3) Chronic bronchitis and emphysema have a certain degree of increased airway reactivity.

(4) Allergic rhinitis, with airway reactivity between normal and asthma.

Abnormal results: Bronchial asthma, chronic bronchitis, emphysema, allergic rhinitis

The population to be examined:

(1) Asthma patients without typical symptoms or those suspected of having asthma who need to be diagnosed through tests.

(2) During the treatment of asthma, it is necessary to measure airway reactivity to guide the medication users.

(3) In scientific research on the pathogenesis of asthma, cases where airway reactivity needs to be measured.