Increased frequency of asymptomatic bronchial hyperresponsiveness in nonasthmatic patients with food allergy.

Subclinical inflammation in gut mucosa has been demonstrated in bronchial asthma suggesting the whole mucosal system is involved in allergic diseases. The presence of subclinical bronchial involvement was assessed by nonspecific bronchial hyperresponsiveness (BHR) in nonasthmatic patients with food allergy (FA). BHR was studied in 35 patients with various manifestations of FA without food-induced asthma. Sixteen had a previous history of asthma and/or rhinitis to aeroallergens (group A), whereas 19 patients (group B) did not. BHR was defined by a provocative dose causing a 20% fall in forced expiratory volume in one second of (PC20) <8 mg.mL(-1) of methacholine. Asymptomatic BHR occurred frequently in nonasthmatic patients with FA (10 of 19, 53%); this did not significantly differ from patients with FA and a previous history of asthma and/or rhinitis to aeroallergens (13 of 16, 81%). PC20 was significantly lower in group A (1.84+/-0.53 mg.mL(-1)) than in group B (3.35+/-0.74 mg.mL(-1); p<0.05). The number of patients with positive skin tests to aeroallergens was similar between groups. Sequential evaluation, performed 1 year after initial evaluation, in 7 nonasthmatic patients (group B) demonstrated a similar level of BHR. The present study demonstrated that BHR is a frequent finding in nonasthmatic patients with food allergy which may be due, at least in part, to a subclinical inflammatory process in the bronchi.