Test your diagnostic skills in our regular dermatology quiz. What is the cause of this painful lesion on an elderly woman’s leg?
An 80-year-old woman presents with a painful, swollen and eroded lesion on her lower leg that has developed over four weeks (Figure 1). She has been previously well and does not recall any recent history of trauma.
The patient has a history of squamous cell carcinoma (SCC) and multiple actinic keratoses. At presentation she is well and afebrile.
A biopsy of the lesion has been performed, revealing nonspecific inflammation with no evidence of malignancy. Culture of the eroded skin overlying the lesion has returned negative results for bacteria. The patient has been prescribed two courses of cephalexin and one course of flucloxacillin, but the lesion has shown no improvement.