Author reply Re: Wafer-like calcification of the spine in ochronosis

We thank the authors for their interest in our manuscript and their valuable observations.¹ We agree that there are other conditions like disseminated melanoma, Addison’s disease, porphyria and drugs that cause blackish discolouration of urine. In the index case, although we have not done the confirmatory test, the classical sequence of events with cutaneous hyperpigmentation, degenerative arthritis involving the spine and knees and the pigmentation of sclera (Ossler’s sign) with classical imaging findings of the spine on radiograph makes ochronosis the likely diagnosis.²