[Contact allergy for corticosteroids].

Contact allergy to corticosteroids is not rare. In some studies prevalence rates up to 6% have been observed among patients suspected of allergic contact dermatitis. Hypersensitivity occurs especially in individuals who have been suffering for years from atopic dermatitis, contact dermatitis of the hands and feet, or stasis dermatitis caused by chronic venous insufficiency. The clinical picture is rarely that of acute allergic contact dermatitis, because the reaction is mitigated by the anti-inflammatory properties of the corticosteroid itself; the diagnosis must be suspected when eczema does not improve or spreads during topical corticosteroid therapy. Application to the mucous membranes less frequently leads to sensitisation. Most such cases are caused by nasal sprays containing tixocortol pivalate or budesonide. Oral or parenteral administration of corticosteroids to sensitive individuals causes exacerbation of pre-existing contact dermatitis or widespread allergic cutaneous drug reactions. Allergological investigation with corticosteroids presents some specific problems, the most important being occurrence of false-negative reactions. Nevertheless, most sensitive patients can be identified by testing the 'indicator' allergens, budesonide and tixocortol pivalate, which should be added to the routine series of contact allergens. Cross-reactions to other corticosteroids occur frequently. This should be taken into account when prescribing alternative corticosteroid preparations.