The frequency and distribution of minocycline induced hyperpigmentation in a rheumatoid arthritis population

Minocycline is particularly useful in patients with rheumatoid arthritis (RA) with previous major sepsis, where anti-tumor necrosis factor is relatively contraindicated. Pigmentation is a documented side effect, but predisposing factors in an RA population have not been established. We investigated minocycline induced pigmentation in a population with RA to determine whether skin type and eye color influence predisposition to this side effect.

Patients with RA attending a rheumatology unit who had received minocycline were contacted by telephone and some were also interviewed in the clinic. Those receiving therapy for more than 3 months were assessed. Hair color, eye color, tendency to burn in the sun, and dose and duration of therapy were documented. The frequency, type, and distribution of pigmentation were established.

Of 37 patients identified, 10 were excluded because the duration of therapy was less than 3 months. Of the remaining 27 patients, 85% were female, with median age 64 years (range 44-88) and median disease duration 23.5 years (range 4-51). Eleven patients (41%) developed pigmentation after a median of 12 months. Four of the 11 stopped their minocycline due to pigmentation. Hair color, eye color, and tendency to burn in the sun did not predict patients who developed pigmentation.

Pigmentation is a common side effect in patients receiving minocycline therapy for more than 3 months. Most patients do not stop therapy due to pigmentation. Those who stop are more likely to be female, less than 70 years of age, and have facial pigmentation.