Minocycline-induced hyperpigmentation in patients with pemphigus and pemphigoid

Immunosuppressive medications typically used to treat the immunobullous disorders pemphigus vulgaris, pemphigus foliaceous, and bullous pemphigoid can have serious adverse effects. The tetracycline family of antibiotic drugs has been shown to be effective in the treatment of these conditions with a more favorable side effect profile. Minocycline hydrochloride use has been associated with various forms of hyperpigmentation, and its incidence is well reported in acne vulgaris and rheumatoid arthritis. We examined a series of 9 patients treated with minocycline for pemphigus or pemphigoid, most of whom have developed cutaneous hyperpigmentation.

Seven of 9 patients treated with minocycline, 50 mg daily (1 patient) or 100 mg twice daily (8 patients), for pemphigus vulgaris, pemphigus foliaceous, or bullous pemphigoid developed hyperpigmentation, which necessitated discontinuing therapy. Five of these patients had experienced notable clinical improvement of their immunobullous disease with minocycline therapy. The average duration of treatment was 8.2 months (range, 1-25 months). The second most common adverse effect in our group was oral candidiasis, which occurred in 2 patients.

We found a favorable response to minocycline therapy in 5 of 9 patients. However, 7 patients developed localized hyperpigmentation as early as 1 month after starting medication use. This incidence of minocycline-induced hyperpigmentation is significantly higher in immunobullous disease than in acne vulgaris or rheumatoid arthritis. This increased incidence may be related to an increase in pigment deposition complexed with collagen during the remodeling process, subclinical inflammation, or glucocorticosteroid-induced skin fragility. The hyperpigmentation process was reversible, as most of our patients had fading of their pigmentation after minocycline cessation.