Cutaneous staining associated with long-term minocycline hydrochloride administration was first brought to the attention of the medical community in 1978.1,2 Since then, numerous accounts of various pigmentation patterns have been reported. This hyperpigmentation occurs in two major forms,3 each of which may represent distinct pathophysiologic processes. In the first form, dark localized blue-black macules are observed in areas of active or previous inflammatory activity.1,4
The second form is characterized by a diffuse hyperpigmentation distant from the site of infection or inflammation. The color in this latter pattern has been described as occurring in various dark shades, including brown,5 blue-brown,6 blue-gray,7 and blue-black.8 In some cases, the areas of predilection have been demonstrated to be those most often exposed to sunlight,7,9 especially the anterior lower extremities. A nonspecific generalized "muddy" hue of the skin may also accompany long-standing minocycline use.2,10,11 In addition,