Pyoderma Gangrenosum

Pyoderma gangrenosum (PG) is a rapidly evolving, idiopathic, chronic, and severely debilitating skin disease. It occurs most commonly in association with a systemic disease especially chronic ulcerative colitis, and is characterized by the presence of irregular boggy, blue-red ulcers with undermined borders surrounding purulent necrotic bases.

Causes of Pyoderma gangrenosum

This disorder can affect any area of the body, including the face. In many cases, the cause isn't known. It may be triggered by trauma or injury to the skin. Also, it can be associated with other disorders, including:

• Inflammatory bowel disease, such as Crohn's disease or ulcerative colitis
• Hepatitis
• Arthritis
• Blood disorders such as leukemia, polycythemia vera or myeloma

Signs and symptoms of Pyoderma gangrenosum

The ulcers appear red/blue with ragged overhanging, tender, necrotic edges. The ulcers often start as pustules or tender red nodules, and may have been related to minor trauma or insect bites . Pain may be so severe to need opiate analgesics. Some patients will have accompanying fever, malaise, muscle and joint pains. Often the lesion heals leaving a cribriform scar.

Breakdown of this lesions occurs with ulcer formation whereby ulcer borders are dusky-red or purple, irregular and raised, undermined, boggy with perforations that drain pus. The base of the ulcer is purulent with hemorrhagic exudate, partially covered by necrotic eschar, with or without granulation tissue. Pustules may be seen at the advancing border and in the ulcer base, and a halo of erythema spreads centrifugally at the advancing edge of the ulcer. Lesions are usually solitary but may be multiple and form in clusters that coalesce

Diagnosis

Clinical findings plus course of illness. A doctor may confirm by removal of a small amount of affected skin (biopsy) for examination under a microscope

Treatment of Pyoderma gangrenosum

Treatment is non-surgical. The necrotic tissue should be gently removed. Wide surgical debridement should be avoided because it may result in enlargement of the ulcer.

Often conventional antibiotics such as flucloxacillin are prescribed prior to making the correct diagnosis. These may be continued if bacteria are cultured in the wound (secondary infection) or there is surrounding cellulitis (red hot painful skin), but they are not helpful for uncomplicated pyoderma gangrenosum.