Local corticosteroid treatment: the effect on cells and cytokines in nasal allergic inflammation.

Regular and prophylactic use of topical corticosteroids is a well tolerated and effective treatment for allergic rhinitis. The symptomatology of allergic rhinitis is considered to be the result of the accumulation and activation of infiltrating inflammatory cells, releasing mediators, and cytokines. Corticosteroids can suppress many stages of the allergic inflammatory process. This may explain their potent effect on allergic symptomatology. The reduction in cell numbers and probably also cytokines by local corticosteroid therapy differs from cell to cell. Some cells, such as antigen presenting (Langerhans) cells and eosinophils, are highly sensitive to corticosteroid treatment. Others, like T cells, are only significantly reduced in exaggerated situations, for instance after provocation with a high allergen dose or after treatment with a high dose of corticosteroids. Some cells, like macrophages, are not influenced at all.