Allergic sensitivity to topical corticosteroids is usually only picked up when an eczematous dermatitis being treated by a topical corticosteroid fails to respond to treatment or worsens. In cases of persistent or exacerbating dermatitis treated with corticosteroid preparations, corticosteroid sensitivity should be considered. However, it may also be due to irritation from or allergy to other components of the preparation such as preservatives . Lanolin , ethylenediamine , quaternium-15 and the antibacterial agent neomycin , are all known to be potent sensitisers.
Long term use of topical corticosteroids can induce tachyphylaxis (tolerance to the vasoconstrictive action of topical corticosteroids). Adverse effects are uncommon when using mild to potent corticosteroids for less than three months, except when used on the face and neck, in intertriginous areas (skin folds), or under occlusion. However, very potent corticosteroids should not be used continuously for longer than three weeks. 2 If longer use of very potent corticosteroids is required, they should be gradually tapered to avoid rebound symptoms and then stopped for a period of at least one week after which treatment can be resumed. 2