Diagnostic utility of skin prick test in fungal asthma

Background: Allergic bronchopulmonary mycosis (ABPM) is a clinical syndrome associated with immune sensitivity to various fungi. Aspergillus spp. predominates in colonizing the airways of asthmatics. Early and accurate identification of fungus in such cases can prevent worsening of asthma. Also, can help in retarding the progression of ABPM. Objectives of this study were to evaluate different fungal allergens associated with clinically diagnosed Asthma patients by Skin Prick testing (SPT), to study total IgE in asthmatic patients by serological testing and to characterize the fungal isolate associated with SPT+ cases by conventional mycological culture. Methods: A prospective study of known asthma cases was done. Their sensitivity to fungal allergens was tested by SPT. The total IgE levels were measured by ELISA. Sputum collected from SPT+ cases were subjected for fungal identification. Results: Out of 175 patients, 25 (14.2%) showed positive reaction against fungal antigens in which fungal growth was seen in 21 (84%) sputum specimens. Aspergillus fumigatus was isolated from 16 (76%) specimens followed by Candida albicans in 3 (14%) and Penicillium spp in 2 (9.5%) cases. Out of 25 SPT+ asthmatics, 21 patients with fungal growth had total IgE levels >600 IU/ml and 4 patients with negative culture had IgE levels 400-500 IU/ml. Conclusions: A significant prevalence of fungal asthma is seen among asthmatics. Thus, it is essential to screen asthma patients for fungal allergy. SPT seems to be a good screening test. SPT is easy to perform, less time consuming and inexpensive however needs to be performed under pulmonologist’s supervision.