Trichostasis spinulosa: possible association with prolonged topical application of clobetasol propionate 0.05% cream

A 20-year-old woman of south Asian descent was concerned about her dark complexion, predominantly affecting the exposed areas of her body, including the face, neck, upper chest, and extremities. She tried multiple over-the-counter products, including topical hydroquinone, kojic acid, and various herbal formulations, without success. Three years previous to her presentation, she was given clobetasol propionate 0.05% cream by a friend, which she applied to the face, neck, upper chest, and arms. After 6 weeks of twice-daily application, she noted marked improvement of her complexion; thus, she continued to use clobetasol propionate cream thereafter. She applied approximately 10 g of cream daily. One year previous to her presentation, she noticed an asymptomatic eruption of tiny dark-brown papules and "open pores" on the face, neck, upper chest, and arms. She thought her dark complexion was returning, and continued to use topical corticosteroid for another year without improvement. She was advised to see a dermatologist. Physical examination revealed multiple, dark-brown, follicular papules involving the face, neck, upper chest, arms, and antecubital areas (Figs 1-3). There was a rough sensation on palpation. On examination with a hand lens, tufts of hairs were visible projecting through each of the tiny papules. Manual attempts to express material from the lesions were unsuccessful. A few of the horny plugs were removed with a sterile needle. Multiple vellus hairs were seen embedded in keratinous material on light microscopy of the extracted plugs (Fig. 4). The patient refused a skin biopsy. In addition to the dark follicular papules, multiple open comedones were present on the malar areas, and hypertrichosis was evident on the chin and lower cheeks. Telangiectasias were also visible over the malar areas and the arms. Her past medical history, the rest of the physical examination, and routine blood and urinalyses, including serum free testosterone, blood urea nitrogen, and serum creatinine levels, were unremarkable. On the basis of the clinical and light microscopic findings, a diagnosis of trichostasis spinulosa (TS) was made. She was advised to discontinue the use of corticosteroid cream. Her treatment consisted of daily tretinoin 0.05% cream over the affected areas at bedtime. A marked improvement of the TS lesions and comedonal acne was noted at the 3-month follow-up visit (Figs 5-7). There was no improvement of the hypertrichosis and telangiectasias.