melasma misdiagnosis

Hydroquinone is commonly used to treat melasma and hyperpigmentation. However, prolonged or unsupervised use can rarely cause exogenous ochronosis, a condition in which the skin becomes darker instead of lighter. What Is Exogenous Ochronosis? Exogenous ochronosis causes blue-black or slate-gray discoloration, most often on the cheeks, temples, or neck. It is an acquired skin condition [...]