Pyoderma gangrenosum can occur on any skin surface, but is most commonly seen on the legs. Patients are often systemically unwell with symptoms such as fever, malaise, arthralgia, and myalgia. Lesions are usually painful and the pain can be severe. When the lesions heal the scars are often cribriform. About half of the cases are associated with underlying systemic conditions, such as inflammatory bowel disease, arthritis, and haematological malignancies.