Corticosteroids

Abstract

Despite their anti-inflammatory and immunosuppressive properties, corticosteroids (CSs) occasionally provoke immediate type I and delayed type IV allergic reactions. Frequency of reactions after topical application is 0.2–5.98 %; for systemic reactions, the incidence is 0.1–0.3 %. The reaction of steroid glyoxals with arginine is important for allergenicity of CSs. Allergic contact eczema is the most common delayed hypersensitivity reaction to CSs. Type IV reactions are mainly diagnosed by patch testing with tixocortol pivalate, budesonide, and hydrocortisone 17-buyrate being the principal drugs employed for testing. A combination of tixocortol pivalate and budesonide detects over 91.3 % of allergic patients. CSs have been classified into four structural groups A, B, C, and D on the basis of clinical cross-reactivity patterns obtained from patch test results. Recently, a new classification divides the CSs into three groups (1) Those that produce most of the allergic reactions—CSs that are non-methylated and usually nonhalogenated. (2) Halogenated molecules with a C16/C17 cis-ketal/diol structure. (3) CSs that produce allergy rarely—halogenated and C16-methylated CSs. Anti-inflammatory and immunosuppressive actions of CSs do not seem to affect immediate reactions. Skin testing, both prick and intracutaneous, together with challenge tests form the basis of the diagnosis of immediate systemic reactions to CSs.