Black bone disease of the foot: a case study and review of literature demonstrating a correlation of long-term minocycline therapy and bone hyperpigmentation.

The chronic use of minocycline and tetracycline has been widely reported in published studies to cause discoloration of skin and teeth. There are very few case reports with regard to discoloration of bone. Those cases reported have been termed black bone disease or blue bone disease because the resulting change to the bone is a blue, green, or brown discoloration that resembles necrotic bone. Documentation of the occurrence in bone, however, is rare, with very few studies noted and only 1 other case that reported changes to the bones of the foot. The mechanism responsible for bone discoloration is not clearly understood. We present a case of this condition encountered during cheilectomy of the first metatarsophalangeal joint in a patient who had required long-term usage of minocycline for adult acne.