We performed a basal spirometry and skin prick tests (SPTs) to a battery of common inhalants that included mites, molds, cat and dog dander, cockroach, and pollens of grasses, weeds and trees.
Forced basal spirometry was normal with a FVC of 3.66 l (116%), a FEV1 of 2.82 l (103%), and a FEV1/FVC of 77%. FEV1 was not modified by inhaled salbutamol. SPTs to inhalants were negative.
The patient was instructed to monitor the peak expiratory flow rate (PEF) until the next visit to the clinic, and some laboratory and X-ray studies were perfomed.
Sinus and chest X-ray were normal.
Whole blood count revealed no abnormalities except blood eosinophilia (1903/mm3).
Biochemical blood determinations were normal, as well as urine test.
Parasites in feces (3 samples) were negative.
Total IgE was 764 kUA/l. Immunoglobulin G, A and M were normal.
Alfa-1 antitrysin was normal.
Specific IgE (CAP) to cat dander, dog dander and cockroach were negative.
The PEF monitoring during 12 days revealed the presence of variations greater than 20% within the same day, in spite of been treated with budesonide 320 µg and formoterol 9 µg twice a day.
During the second visit we performed a methacholine bronchial challenge test to quantify the degree of non specific bronchial hyperreactivity. The PC20 methacholine was 2.50 mg/ml.