Approach to a patient of facial hyperpigmentation

A middle-aged man presented with an 8-year history of slowly progressive brown-black pigmentation on both cheeks. The patient gave a history of unsupervised application of 4% hydroquinone cream for facial hyperpigmentation. Initially, his pigmentation lightened, but it subsequently darkened and spread despite continued use. Cutaneous examination revealed bilaterally symmetrical reticulate gray-brown to black macules on the malar and temporal regions. Dermoscopy of a lesion showed irregular brown-grey globules and curvilinear 'worm-like' structures with obliteration of follicular openings. A skin biopsy demonstrated ochre-coloured, banana-shaped pigment deposits within dermal collagen bundles (so-called 'banana bodies') with homogenised, swollen collagen. These findings confirmed exogenous ochronosis (EO) due to prolonged hydroquinone exposure. Early recognition of EO is important because its clinical features can mimic melasma and other facial melanoses. In this case, non-invasive dermoscopy provided characteristic clues suggestive of ochronosis, avoiding the need for multiple invasive biopsies. The patient was advised to discontinue hydroquinone and begin strict photoprotection and topical retinoid therapy, with consideration of Q-switched laser treatments.