Atopic dermatitis and bronchial asthma are genetically dependent diseases, connected with an over-synthesis of IgE antibodies, in which a chronic inflammation is characteristic for their pathogenesis. The coincidence of bronchial hyperresponsiveness and symptoms of atopic dermatitis suggests to investigate the degree of bronchial reactions in atopic dermatitis or asthma patients. The main goal of this analysis was to compare the pulmonary functional tests and the bronchial histamine induced reactiveness in 71 patients. The investigation included 27 atopic dermatitis patients, 12 asthma-prurigo patients and 32 bronchial asthma patients. All of them were tested with "Pneumoscreen" (Jaeger), in order to define: VC, FEV1, FEF50, and Raw. The bronchial reactiveness with 1% histamine solution, was tested on "Bronchoscreen" (Jaeger). In atopic dermatitis and asthma-prurigo patients, no obstructive ventilation impairment was found. The bronchial hyper-reactiveness to histamine was found in 11.1% of atopic dermatitis patients, 16.7% of asthma-prurigo patients and 78.1% of bronchial asthma patients. The coexistence of bronchial asthma and atopic dermatitis increases the degree of bronchial reactiveness.