Striae atrophicans: A mimic to Cushing′s cutaneous striae

Abstract

Sir, A 30-year-old male patient was referred for evaluation of Cushing's syndrome when he presented with purple striae over both the thighs [Figure 1] for 1 month. He did not have any systemic symptoms. There was no history of any drug intake including oral or parenteral steroids. He was applying steroid ointment (halobetasol propionate 0.05%) for fungal infection locally for 3 months prior to this. These striae were violaceous, with the largest one measuring 10 cm in length and 1.8 cm in width, which is classical for Cushing's syndrome. His body mass index was 26.0 kg/m2. He did not have any systemic effects of steroid, though human and animal studies indicate that less than 6% of the applied dose of halobetasol propionate enters the circulation within 96 hours following topical administration of the cream.[1] His morning and evening cortisol levels were 10.65 μg/dL and 5.28 μg/dL, respectively. Overnight dexamethasone test revealed suppressible serum cortisol (0.55 μg/dL). Halobetasol propionate cream produced hypothalamic-pituitary-adrenal (HPA) axis suppression when used in divided doses at 7 g/day for 1 week.[2] His serum cortisol level following adrenocorticotropic hormone (ACTH) stimulation test was 25.6 μg/dL. He was diagnosed as a case of striae atrophicans, which is a known complication of chronic application of topical steroid preparations. Halobetasol is grouped under ultra high potency topical steroid and has more propensity to cause side effects. The glucocorticoids affect the epidermis by preventing the fibroblasts from forming collagen and elastin fibers, necessary to keep the rapidly growing skin taut. This creates a lack of supportive material, as the skin is stretched and leads to dermal and epidermal tearing.[3] Topical application of steroids is known to cause systemic effects of hypercortisolism and suppression of HPA axis, but this is very rarely manifested clinically and is easily reversible. This patient has neither any systemic manifestation nor any evidence of adrenal suppression. Figure 1 Multiple cutaneous striae at thigh