Dental sinus tracts mimicking scrofuloderma: cutaneous presentation of underlying bisphosphonate-related osteonecrosis of the jaw.

Bisphosphonates are potent inhibitors of osteoclastic bone resorption, and have been used for decades to control medical conditions associated with an increase in bone resorption, such as bone metastases and osteoporosis. Osteonecrosis of the jaw (ONJ) is a devastating side-effect of bisphosphonate therapy, which presents as exposed bone, accompanied by pain, swelling and purulent secretions. Although predominantly recognized by oral and maxillofacial surgeons because of the bony and intraoral features of the disease, ONJ may also present on the skin as a cutaneous sinus tract. We present the case of a 67-year-old woman who presented with ONJ after oral bisphosphonate treatment for osteoporosis.