A rare cause of ulceration with a promising new treatment

Conflict of interest: none declared. A 77‐year‐old woman presented with a 4‐week history of painful ulceration on her left calf. The skin had previously been normal, and there was no history of trauma. The patient had a history of ischaemic heart disease, type 2 diabetes, hypertension and atrial fibrillation. Her medication on admission included furosemide, enalapril, felodipine, warfarin, metformin, nebivolol and glargine. On examination, a well‐defined ulcer with a violaceous border and central eschar formation was seen (Fig. 1a). Peripheral pulses were easily palpable despite bilateral pitting oedema to the knees. Ankle brachial pressure index was 1.1 (right) and 0.9 (left) with triphasic signals. There were no varicosities, and peripheral sensation was intact. The patient was apyrexial and had a body mass index of 37. The remainder of the examination was normal. Blood tests on admission gave normal results for renal, haematological, liver, bone, thyroid function and vasculitic screen. Further blood tests revealed low levels of phosphorous (0.7 mmol/L; normal 0.8–1.6), magnesium (0.63 mmol/L; 0.7–1.0) and vitamin D (8.7 ng/mL; 16–74), raised parathyroid hormone (PTH) level (7.3 pmol/L; 1.6–6.9), and normal 1,25 dihydroxycholecalciferol level (24 pg/mL; 20–50). Serum corrected calcium, calcium phosphate product, urinary calcium and 24‐h urinary calcium were within the normal range. Further imaging excluded an underlying malignancy.