Skin pigmentation associated with minocycline therapy

Abstract

A patient on long-term minocycline therapy developed blue-black discoloration on the legs. Skin biopsy specimens from the pigmented areas were examined by light and electron microscopy and energy-dispersive X-ray microanalysis. Pigmented granules were present at all levels of the dermis and subcutaneous fat tissues. Ultrastructural examination showed electron-dense granular material within the cytoplasm of dermal macrophages and energy-dispersive X-ray microanalysis indicated that the granules contained iron. Thyroid tissue obtained by aspiration biopsy showed the presence of fine brown granules within the cytoplasm of the follicular epithelial cells. An extract of skin from the pigmented areas was subjected to high performance liquid chromatography and minocycline was detected.

Minocycline-Induced DRESS: Evidence for Accumulation of the Culprit Drug

“…On the other hand, pigmentation is a frequent cutaneous side effect of minocycline affecting about 15% of patients under treatment. Three patterns of minocycline-induced pigmentation have been described [5], and pigmentation was linked to the presence of minocycline in the skin [6, 7] which persisted for months after withdrawal of the drug. By analogy, we hypothesized that the prolonged course of minocycline-induced DRESS was linked to a similar accumulation of the drug.…”

Mechanism of Pigmentation by Minocycline in Murine B16 Melanoma Cells

“…21) Minocycline itself and/or its iron chlate may induce melanin deposition because iron and minocycline were reported to be detected in the pigmented skin after minocycline therapy. 22) Although the above events were conrmed, the mechanism by which minocycline induces pigmentation in tissues has not been entirely elucidated. In this study, we conˆrmed that the melanin levels in B16 melanoma cells were increased following minocycline treatment.…”

“…Okada et al reported that iron and minocycline were detected in the pigmented skin associated with minocycline therapy. 22) The pigmentation appears to involve melanin, hemosiderin, or a combination of the two with a possible melanin-drug complex. 23) The mechanisms of minocycline-induced pigmentation, however, have been unclear.…”

Systemic Antibiotics for Acne

“…Hyperpigmentation or blue-back pigmentation in general occur after prolonged exposure to minocycline; it involves scar tissue or sun-exposed skin and usually fades slowly after discontinuing treatment; the cause of this complication has been speculated to be iron deposits, oxidized minocycline deposits, iron minocycline complex and melanin [64, 65, 66, 67, 68]. The pigmentation can reach the conjunctiva, buccal mucosa [64, 69], lips [70] and bone to create a dark bone pigmentation severe enough to be visible through the alveolar and palatal mucosa [71].…”