Introduction: Histamine directly interacts with airways smooth muscles to initiate contraction. This occurs even at low concentrations among individuals predisposed to increased airway inflammation and asthma.
Methods: A digital vitalograph, nebulizer, histamine, and pulse oximeter were used in this research. A total of one hundred and sixty subjects were selected and categorized into two groups; Group 1 (Test subject) and Group 2 (Control), each group contained eighty (80) subjects. Group 1 comprised occupationally exposed vulcanizers and Group 2 comprised selected students from the University of Calabar as control. Both groups comprised young male subjects of equal age (20-40 years), devoid of pre-existing respiratory disorders or on any medication(s). Demographic parameters were used to obtain sufficient information for overall analysis. Lung parameters (FVC, FEV1, PEFR, and FEV1%) were evaluated using a Vitalograph Spirometer.
Results: Basal measurement showed that Group 1 had a moderate decrease in lung volumes (FVC, FEV1, PEFR, and FEV1%) of 65 subjects (representing 81.25%) and a mild decrease in 15 subjects (18.75%); all the subjects in Group 2 showed a mild decrease in lung volumes. Inhalation of histamine mist of different concentrations showed that Group 1 had a severe decrease in lung volumes of 70 subjects (87.5%) and a mild decrease in 10 subjects (12.5%). All Subjects in Group 2 showed a mild decrease in lung volumes.
Conclusion: Histamine provocative test helps to evaluate asthma signs and symptoms. Airways Hyper reactiv-ity is associated with inflammation as a consequence of airway hyperreflexia. It is evidenced that associated pollutants and their chronic inhalation by the vulcanizers have a retrogressive impact on their airways which manifests with hyper response an indication for asthma signs.