Extrait de Medscape
Corticosteroids are another group of allergens increasing in significance. The increase in allergic contact dermatitis seen to corticosteroids may be a result of increased use of corticosteroids, increased awareness of allergy to cortico steroids, increased patch testing for these potential allergens, or because of the availability of better screening allergens.
Corticosteroid allergy should be considered if a dermatitis is not responding to treatment, if a dermatitis worsens with corticosteroids, or in the management of chronic dermatitis such as stasis dermatitis, atopic dermatitis, or hand eczema that does not improve.
There are four general classes of corticosteroids (classes A-D) based on chemical structure with cross-reactions occurring between classes. Class A steroids include steroids such as hydrocortisone and hydrocortisone acetate. Class B steroids include, but are not limited to, triamcinolone acetonide, flucinoinide, and desonide. Identifying a particular class of steroid that a patient is allergic allows for switching classes and avoiding the causative allergen and hopefully resolving the dermatitis.
The most common screening allergens are tixocortol-21-pivalate which screens for Class A, and budesonide which screens for Class B allergy. If positive reactions are found to these screening allergens, patch testing to an expanded corticosteroid series should be considered. Patch testing with corticosteroids should be performed carefully as delayed reactions may be seen because of the anti-inflammatory properties of these compounds. Therefore, a second delayed patch test reading is necessary to fully evaluate for allergic contact dermatitis to corticosteroids.