Decreased prevalence of atopy in paediatric patients with familial Mediterranean fever.

BACKGROUND A number of inflammatory diseases, including familial Mediterranean fever (FMF), have been shown to be driven by a strongly dominated Th1 response, whereas the pathogenesis of atopic diseases is associated with a Th2 response. OBJECTIVE Because dominance of interferon gamma has the potential of inhibiting Th2 type responses-that is, development of allergic disorders, to investigate whether FMF, or mutations of the MEFV gene, have an effect on allergic diseases and atopy that are associated with an increased Th2 activity. METHOD Sixty children with FMF were questioned about allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis, as were first degree relatives, using the ISAAC Study phase II questionnaire. The ISAAC Study phase II was performed in a similar ethnic group recruited from central Anatolia among 3041 children. The same skin prick test panel used for the ISAAC Study was used to investigate the presence of atopy in patients with FMF and included common allergens. RESULTS The prevalences of doctor diagnosed asthma, allergic rhinitis, and eczema were 3.3, 1.7, and 3.3%, respectively, in children with FMF, whereas the corresponding prevalences in the ISAAC study were 6.9, 8.2, and 2.2%, respectively. Only the prevalence of allergic rhinitis was significantly different between the two groups (p<0.001). The prevalence of atopy in these patients with FMF (4/60 (7%)) was significantly lower than in the children of the population based study (20.6%) (p<0.001). CONCLUSION Family Mediterranean fever seems to be protective against development of atopic sensitisation and allergic rhinitis.