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Papulonecrotic tuberculide complicating scrofuloderma in a health‐care worker

with malignancy (lymphoma). However, there has been no previous report of RPC associated with periampullary carcinoma as in this case. The pathogenesis of RPC is unknown. Mehregan et al. speculated in their original article that trauma to the skin leads to an alteration in the dermal collagen, which is subsequently extruded from the dermis. In the acquired type, the association of RPC with diabetes mellitus and/or chronic renal failure and haemodialysis can be considered causal. However, whether the metabolic disturbance of these diseases directly affects the pathological change of RPC, whether pruritus is predisposing and to what extent immunological or biochemical events precipitate the manifestations have yet to be clarified. In a review of 22 cases, Faver et al. insisted that acquired RPC is a reaction to superficial trauma caused by scratching in association with many pruritic diseases. Recently, Pedragosa et al. reported two cases of RPC in Hodgkin’s disease and suggested on the basis of the skin changes seen in their patients that RPC is simply a consequence of intense itching and vigorous rubbing. Also, in this case, we cannot exclude the possibility that pruritus secondary to cholestatic jaundice caused by enterohepatic obstruction of periampullary carcinoma may be responsible for the development of RPC. However, this possibility must be very small because the skin lesions of RPC developed earlier than jaundice in this patient. Furthermore, the patient denied chronic rubbing or scratching. Based on the observation of the simultaneous occurrence of RPC and internal malignancy and their parallel course (i.e. the resolution of the skin eruption shortly after removal of the tumour) in this patient, it seems that there is a causal relationship between the two disorders, although the pathomechanism is not known. Hence, we suggest that an acquired type of RPC may occur as a paraneoplastic condition associated with internal malignancy. The study of further cases is necessary in order to elucidate this relationship.