Minocycline-induced blue sclera and skin hyperpigmentation

A 73-year-old man presented to the emergency department with lethargy and influenza-like symptoms. Incidentally, prominent blue sclera and blue-grey skin discolouration to the periorbital skin, pinnae, neck, upper and lower limbs, hands, feet, fingernails and toenails were noted. His general practitioner (GP) had previously ceased amiodarone, believing it to be the causative agent. A literature search confirms the side effects were likely due to minocycline, which the patient had been taking for 10 years. Long-term minocycline use is associated with scleral and skin hyperpigmentation, with no apparent adverse effect on ocular structure or function. The pigmentation may reverse with cessation of minocycline, or it may be permanent. Amiodarone may also cause skin hyperpigmentation, but scleral pigmentation is not a known association. This case report explores the side effect profiles of these two drugs, and highlights the potential for confusion regarding causative agents when used concurrently.