Diltiazem-Induced Hyperpigmentation

A healthy-appearing 66-year-old black woman presented with a 5-year history of facial hyperpigmentation that was unresponsive to topical sunscreen, hydroquinone, tretinoin, and azelaic acid. Her medications included extended-release diltiazem for hypertension for the past 7 years, rofecoxib for arthritis, and pantoprazole for esophagitis. On examination, the woman displayed hyperpigmented patches and papules involving most of her face. The punch biopsy findings from a hyperpigmented papule on the right temple revealed compact hyperkeratosis, follicular dilation, and dense inflammatory infiltrate along the dermal-epidermal junction with abundant dying keratinocytes. Her diltiazem therapy was discontinued, which led to gradual resolution of her hyperpigmentation.