Minocycline-Induced Blue-Gray Discoloration

At the time of our consultation, we observed a prominent bluegray discoloration characterized by symmetric patches localized on the temporal, preauricular and periorbital skin ( Fig. 1 ), while the trunk, limbs, and the mucosae were spared. Routine blood tests and other recent investigations excluded the most common causes of hyperpigmentation, including Addison disease, hyperthyroidism or malignancy. A skin biopsy from the pigmented skin showing prominent solar elastosis, epidermal thinning, and focal hyperpigmentation of the basal layer was not helpful for a diagnosis. A more detailed medical history revealed that the patient had been taking minocycline 100 mg every other day for nearly 10 years. In fact, he had observed an improvement of a folliculitis of his trunk after minocycline prescription from his physician; he had therefore continued to take the drug autonomously. Minocycline intake was immediately stopped and a diagnosis of minocycline-induced pigmentation was made. At 2 years of follow-up, the face discoloration was still present, although less prominent ( Fig. 2 ). The patient refused any surgical procedure, such as laser treatment or skin bleaching agents. Disorders of pigmentation are usually due to the deposition of melanin and an increase in active melanocytes. The clinical features are characterized by blue-black or blue-gray diffuse or pitted pigmentation primarily of the face, extremities and other photoexposed areas. Various exogenous factors can be involved, including inflammation and injury (postinflammatory hyperpigmentation). Differential diagnosis includes various dermatoses of unknown etiology, such as erythema dyschromicum perstans or ashy dermatosis, lichen planus pigmentosus and melasma or argyria,