THE STUDY OF COCKROACH ALLERGY IN IRANIAN CHILDREN WITH ASTHMA

Asthma is the most common chronic disease of childhood. Exposure to allergens plays an important role in asthma. Recently, cockroach has attracted attentions as an important allergen. This study was performed to evaluate cockroach allergy in Iranian children with asthma. One hundred children with definite diagnosis of asthma were selected. After obtaining primary information, the severity of their disease was determined according to their history, physical exam and measurement of PEFR (Peak Expiratory Flow Rate) with a mini peakflowmeter. Also, serum total IgE and blood eosinophil count were measured. The patients were skin prick tested with cockroach (Blattella germanica), trees, weeds, grasses, cats, mite, feather and common food allergens. According to cockroach skin prick test (SPT) results, the patients were divided into two groups (sensitive and non‑sensitive) and compared. Positive SPT for cockroach was detected in 29% of patients. Cockroach sensitive group had a more severe asthma than non-sensitives (P<0.02). Also, asthmatic patients with cockroach allergy had perennial symptoms (P<0.05). A remarkable number of sensitive patients were born in winter (P<0.05). Eosinophilia was more common in sensitive group (P<0.02) and they had a higher level of serum total lgE (P<0.04). Prevalence of cockroach allergy was near to other common aeroallergens. Cockroach sensitive group had perennial symptoms, which is compatible with other indoor allergens. Cockroach allergy was more prevalent in children born in winter. Maybe these children are kept at home during their first months of life and are more exposed to cockroaches. The higher prevalence of eosinophilia and higher lgE level in sensitive group may be the reasons of more severe asthma in this group.