Diagnosis and treatment of pyoderma gangrenosum

Introduction

Pyoderma gangrenosum is a rare but serious ulcerating skin disease, the treatment of which is mostly empirical. Pyoderma can present to a variety of health professionals and several variants exist that may not be recognised immediately. This can delay the diagnosis and have serious clinical consequences.1 The mainstay of treatment is long term immunosuppression, often with high doses of corticosteroids or low doses of ciclosporin. Recently, good outcomes have been reported for treatments based on anti-tumour necrosis factor α, and infliximab proved effective in a randomised controlled trial. This article reviews the presentation of pyoderma gangrenosum and the therapeutic options available.

Methods

We used the keyword “pyoderma gangrenosum” to search Medline. We also searched the Cochrane database but found no Cochrane review on this disease.

How can pyoderma be recognised?

Several variants exist, but the most common one is classic pyoderma gangrenosum. This presents as a deep ulcer with a well defined border, which is usually violet or blue. The ulcer edge is often undermined (worn and damaged) and the surrounding skin is erythematous and indurated (fig 1). The ulcer often starts as a small papule or collection of papules, which break down to form small ulcers with a “cat's paw” appearance. These coalesce and the central area then undergoes necrosis to form a single ulcer.

Classic 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. Early diagnosis and prompt treatment reduce the risk of scars, and disfigurement may occur if the diagnosis is missed.1 Pathergy occurs in 25-50% of cases—lesions develop at the site of minor trauma, so surgery or …