Late-Stage Exogenous Ochronosis—Not What You Think?

Summary: Exogenous ochronosis is an acquired skin dyschromia arising most commonly from chronic hydroquinone use in skin-lightening products. It results in blue-black pigmentation that typically appears in areas exposed to sunlight, such as the face and neck. Histology is usually diagnostic with distinctive yellow-brown curvilinear ochronotic fibers known as “banana bodies”. However, it has been reported that the histology of late-stage exogenous ochronosis can present with a different pattern of superficial and mid-dermal basophilic, thickened collagen fibers in lieu of the typical pathognomonic “banana bodies”. Herein, we describe the clinical and pathologic findings of a 41-year-old female with a five year history of dark brown-to-black papules scattered about her face and extremities, consistent with late-stage exogenous ochronosis.