Exogenous ochronosis masquerading refractory melasma

Exogenous ochronosis is an infrequent dermatosis characterized by dark blue hyperpigmentation. It may be caused largely by hydroquinone, a fenolic compound which is used in the treatment of melasma and other skin hyperpigmentation. The exact etiopathology is still not understood and the results of various treatments offered are unsatisfactory. We present a case of exogenous ochronosis which resembled melasma but clinicopathologic evaluation led to the correct diagnosis. We also emphasize the need to restrict the indiscriminate use of hydroquinone containing compounds without medical prescription.