Differential Dx includes Addison’s disease
Addison’s disease, hemochromatosis, and melanoma all make up the differential.
The hyperpigmentation of Addison’s disease is a characteristic brown or bronzing of the skin, most notably in the creases of the hands. Mucous membranes may develop a bluish pigmentation.
Patients with hemochromatosis develop bronzing of the skin caused by iron deposits in the dermis. This pigmentation is characterized by a generalized metallic or slate gray coloration of the face, neck, upper extremities, lower legs, and genitals. This coloration also appears in scars.
Melanoma was less likely in this case because of the uniformity of pigmentation on the skin and sclera, as well as the symmetrical pigmentation of the sclera. A skin biopsy would be helpful in ruling out melanoma.6
A biopsy of this lesion would show granules within macrophages that stain positive for iron and melanin, confirming the clinical diagnosis of minocycline-induced hyperpigmentation.2
Patients may not want to wait for discoloration to go away
Some patients find the benign hyperpigmentation cosmetically undesirable and may not want to wait to see if the discoloration goes away. The Q-switched ruby laser has been successful in removing minocycline-induced hyperpigmentation of the skin and oral mucosa.2
Our patient stopped the drug, and saw (some) improvement
Once the diagnosis was made, our patient stopped taking minocycline—which she’d been taking at a low daily dose for 4 years. She was started on metronidazole for her rosacea. Three years later, the patient had a slight clinical improvement in the bluish appearance of her face and sclera.
Minocycline is still a good option for the treatment of acne and rosacea. If you prescribe it, though, be sure to monitor for hyperpigmentation on a regular basis.
CORRESPONDENCE Jay Shubrook, DO, associate professor of family medicine, director of clinical research, Cornwell Center, O’Bleness Memorial Hospital, 65 Hospital Drive, Athens, OH 45701; shubrook@ohio.edu.