Sensitisation to mites in a group of patients with asthma in Yaounde, Cameroon: a cross-sectional study

OBJECTIVES Sensitisation of asthmatic patients to mites in sub-Saharan Africa has been less described. The aim of this study was to assess the prevalence and determinants of sensitisation to mites in asthmatic adolescents and adults in Yaounde, Cameroon. DESIGN This was a cross-sectional study. Logistic regression models were employed to investigate the determinants of sensitisation to mites. SETTING This study was carried out at the Jamot Hospital and CEDIMER private centre, in Yaounde, capital city of Cameroon. PARTICIPANTS All asthmatic patients received in consultations from January 2012 to June 2013 and in whom prick-skin tests for perennial aeroallergens were performed were included. OUTCOME MEASURES Prevalence of sensitisation to mites and associated factors. RESULTS In total, 201 patients (132 being women, 65.7%), with a median age of 36 (25th-75th centiles: 20-54) years were included, with 135 (67.2%) having a positive skin test for mites. Sensitisation to Dermatophagoïdes pteronyssinus, Dermatophagoides farinae and Blomia tropicalis was found in 53.2%, 49.8% and 47.8% of the patients, respectively. Intermittent rhinitis (16.3% vs 7.6%) and persistent rhinitis (43.0% vs 22.7%) were more frequent in sensitised patients than in the non-sensitised ones (p<0.010). Independent allergological determinants of sensitisation to mites were sensitisation to Alternaria alternata (adjusted OR 14.98 (95% CIs 1.96 to 114.4)) and sensitisation to Blattella germanica (3.48 (1.34 to 9.00)). CONCLUSIONS Sensitisation to mites was found in about two-thirds of asthmatic patients in this setting, with a frequent multiple sensitisations to A alternata and Blattella germanica. Systematically investigating asthmatic patients for mites' sensitisation and determinants will help optimising the care in this setting by combining the aetiological treatment for the allergy with symptomatic treatment for asthma, in order to modify the natural course of the disease.