Answer to Image of the Month May 2015
Submitted by Inchara YK
Exogenous ochronosis
This patient presented with hyperpigmentation of the face, treated for melasma earlier. The biopsy shows ochre coloured, crescentic, thickened fibres of collagen (banana bodies). Scattered melanophages are evident. Exogenous ochronosis is a rare disease, often associated with prolonged use of hydroquinone, or phenol containing topicals. Antimalarials and mercury are also implicated. In contrast to the endogenous form, the disease is localised and there is no systemic involvement. The characteristic changes in collagen fibres are diagnostic. Ochronosis should be suspected in refractory pigmentation and biopsied promptly in order to avoid continued usage of the offending agent.