[Corticoids and allergy].

Inflammation is constantly observed in allergic reactions. Corticosteroids are most effective in preventing the late phase of allergic reaction. The action of glucocorticosteroids is mediated through glucocorticoid receptors present in the cellular cytoplasm. When activated, glucocorticoid receptors form a dimer and bind to DNA after migration into the nucleus. Interaction to DNA induces changes in the transcription rate, leading to either gene induction or gene repression. Glucocorticoid receptors are also able to interact with transcriptional factors such as AP-1 (activator protein-1) of NF-kappa B (nuclear factor-kappa B). Through these actions glucocorticosteroids are susceptible to modify functions of cells involved in the allergic inflammatory response. They are in particular able to inhibit most of the pro-inflammatory functions of the eosinophils.