A27-09 Allergen Testing and Spirometry in Nigerian Children With Asthma

Abstract

Abstract Rationale Childhood bronchial asthma is a major cause of morbidity and mortality in developing countries. Allergen testing and spirometry provide vital information for diagnosing and managing asthma in children. However, in developing countries, there is limited availability of allergen test kits and spirometry. In centers where these are available, accessibility is also limited as a result of exorbitant costs. As a result, children with clinically diagnosed asthma may require management without allergen testing and spirometry in spite of the importance of these investigations. This study set out to identify the association between positive allergen test, Forced Expiratory Volume in 1 Second (FEV1), Forced Vital Capacity (FVC) and FEV1/FVC ratio on spirometry. Methods This was a pilot study carried out over a 12-month period. Sixty (60) children with clinically diagnosed asthma were recruited. Anthropometry, skin prick test and spirometry were conducted on all the subjects. The skin prick test was conducted using a 9-allergen extract kit comprising mold species (Cladosporium herbarium, Alternaria alternata, Aspergillus fumigatus and Bloma tropicalis), Dust mite (Dermatophagoides pteronyssinus), Cat dander, Dog dander, Grass and German cockroach. Allergen sensitization was defined as wheal diameter of ≥ 3mm measured after 20 minutes of testing. Spirometry was conducted using the manual EasyOne ™ spirometer. FEV1 and FVC of < 80% of the predicted value were classified as abnormal. FEV1/ FVC ratio of < 75% of the predicted value was classified as airway obstruction. Results There was a total of sixty (60) children during the study period. There were more males than females (61.7% v 38.3%). The mean age of respondents was 9.2± 2.4 years. Positive skin prick testing to Bloma tropicalis was recorded in more than half (53.3%) of the respondents followed by Grass with 51.7%. The allergen with the lowest positive reaction was Dermatophagoides pteronyssinus. Polysensitization was observed in more than two-thirds (68.3%) of subjects. The ratio of FEV1 to FVC revealed an obstructive pattern in 28.3% of study participants. Participants who had positive reaction to Aspergillus fumigatus had lower FVC and FEV1 values (p = 0.032 and 0.015 respectively), while those who reacted to Dog dander had lower FVC values (p = 0.033). Conclusion This study brings to the fore the effect of allergen sensitization on the airway of children with bronchial asthma. It also emphasizes the importance of allergen testing and spirometry which should be provided at subsidized costs in developing countries to improve the management of childhood bronchial asthma. This abstract is funded by: None