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Steroid atrophy, or corticosteroid-induced dermal atrophy, is a side effect of prolonged application of topical corticosteroids. The potential for the condition exists whenever topical corticosteroids are used, even with low potency preparations. Skin atrophy, along with other undesirable side effects such as telangectasia and striae, can appear within 2 to 3 days of starting daily application, the greatest potential occurring when the application is occluded or when the preparation is applied to fragile skin. Risk depends on the strength of the steroid, the length of application, the site treated, and the nature of the skin problem. == Cause == Within two weeks of starting Topical Steroid treatment, and probably within a few days, microscopic degenerative changes may be seen in the epidermis with a reduction of cell size and the number of cell layers. These effects may be rapidly reversible but with chronic administration dermal changes become apparent. There is inhibition of the mitotic activity of fibroblasts resulting in reduction of collagen and glycosaminoglycan synthesis but probably the earliest evidence of dermal atrophy is a reduction in the diameter of the fibrils and then the collagen bundles become atrophic and separated. The latter effects have been reported to be caused by the inhibition of collagenase by steroids. Elastin fibres in the upper layers of the dermis become thin and fragmented whereas those deeper down compact into a dense network. As a result of atrophic changes such as striae, telangiectasias, purpura and ecchymosis develop. Long-term use of steroids causes irreversible atrophy, while atrophy induced by short-term use may to some extent be reversible except for striae. Corticosteroids are absorbed at different rates depending on the thickness of the stratum corneum. A mild topical steroid that works on the face may achieve little on the palm. But a potent steroid may quickly cause side effects on the face. For example: * 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Steroid atrophy」の詳細全文を読む スポンサード リンク
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