Characterization of the asthmatic population of St. Vincent and the Grenadines: asthma severity levels and atopic sensitization.

Background. The developing country of St. Vincent and the Grenadines (SVG) reported a 4.5-fold increase in wheezing incidence between 1986 and 2002. It is unknown whether aeroallergens play a significant role in asthma in SVG. Objective. The objective of the study is to investigate the importance of aeroallergens and the association between age and persistence of asthma into adulthood. Methods. Subjects were recruited from the National Asthma Clinic. Asthma was diagnosed in 525 participants and severity levels assigned according to the National Heart, Lung, and Blood Institute guidelines. Participants were separated into three age groups [<= 6 years (n = 176), 7-18 years (n = 164), and = 19 years (n = 185)]. Skin testing was performed on 171 participants to dust mite, cat, dog, cockroach, pollens, and mold. Age of asthma onset was obtained. Results. Persistent asthma was diagnosed in 235 participants (44.8%) and increased with increasing age group (p < .0001). Atopy was identified in 121/171 (70.8%) participants and was significantly higher in persistent asthma (p < .004). A significant positive association was seen between atopy and age group (p < .0004) in participants with intermittent asthma but not in participants with persistent asthma. The most common allergen among the atopic participants was house dust mite (93.4%), followed by cockroach (47.9%). Adult participants reporting asthma onset in adulthood were less atopic than those whose asthma developed <= 18 years of age (p < .05). Conclusions. The predominance of asthma with atopy in SVG implicates a role for atopy in the sudden rise in asthma cases. This asthma characteristic and the increase in persistent asthma with age in SVG are similar to those reported in the developed countries.