Although ethnicity may influence response to treatment of patients with asthma, this approach is controversial. The objective of this study was to determine if ethnicity influences the response to IM steroid use (eliminating adherence as an issue).
Children with severe therapy-resistant asthma who had previously undergone a detailed assessment (including a nurse-led hospital and home visit in which potentially modifiable factors had been identified and addressed) were admitted for further evaluation; this evaluation included assessment of steroid response. Children were classified as white, black, Asian, or mixed white/black. Steroid responsiveness was defined according to symptoms (Asthma Control Test), inflammation (sputum eosinophil count and exhaled nitric oxide), and spirometry (FEV1); these variables were measured before and 4 weeks after IM triamcinolone use. Data were collected regarding exacerbations. Fractional exhaled nitric oxide (Feno) response was defined as a decrease to < 24 parts per billion (ppb).
Seventy-nine subjects were identified (white, n = 54 [68%]; black, n = 16 [20%]; Asian, n = 5 [6%]; and mixed white/black, n = 4 [5%]). After administration of triamcinolone, there was a significant drop in median Feno in white children (46.8 to 23.1 ppb; P < .001) but not in black children (52.2 to 34.5 ppb; P = .58). More black children than white children (86.7%) were Feno nonresponders (86.7% vs 45.3%; P < .05), and more black children had exacerbations compared with white children (61% vs 17%; P < .05).
Black children with asthma were less likely to report an Feno response and had more exacerbations 4 weeks after administration of triamcinolone than white children. Further research is needed to understand the mechanisms of these differences, but they cannot be due to differences in adherence or access to care.