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Increased Bronchial Hypersensitivity after Early and Late Bronchial Reactions Provoked by Allergen Inhalation
Author(s) -
Machado L.
Publication year - 1985
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.1985.tb00886.x
Subject(s) - methacholine , provocation test , medicine , asthma , inhalation , allergen , airway obstruction , allergy , airway , immunology , anesthesia , respiratory disease , lung , pathology , alternative medicine
The non‐specific bronchial reactivity following bronchial allergen challenge was studied in 40 patients with allergic bronchial asthma, particularly in subjects without definite late reactions 6 h after the provocations (reduction in peak expiratory flow or forced expiratory volume in 1 s of less than 15% of the control value at this time). Among a group of 21 patients submitted to bronchial provocation tests, 13 carried out maximal exercise tests 6 h and 1 week after the allergen challenge. In another group of 19 patients, the bronchial hyperreactivity to methacholine was assessed before and 6 h and 1 week after challenge. Two patients with a dual response (early + late) reacted with bronchial obstruction to the exercise. Exercise tests performed after 1 week did not provoke asthma in any patient. In the methacholine group a marked increase in responsiveness to methacholine 6 h after the provocation was observed in those patients with a dual response who were tested and in those with equivocal late reactions and even in three patients with an isolated immediate reaction. The increased responsiveness was still present in many patients 1 week after challenge. The airway caliber did not influence the degree of responsiveness to methacholine. Nor did the degree of responsiveness have any influence on the patterns of reactions observed after allergen exposure. It was concluded that in some individuals exposure to the relevant allergen predisposes them to exercise‐inducible bronchial obstruction. Further, it was confirmed that nonspecific bronchial reactivity can be increased not only in patients with late responses ‐ both definite and equivocal ‐ but also in some patients with immediate reactions alone. It is suggested that only allergens provoking late reactions or an increase in the non‐specific reactivity should be considered clinically relevant.