Pyoderma gangrenosum (PG) is a rare inflammatory skin disorder characterized by small red bumps or blisters which eventually become ulcerated. The size and depth of the ulcerations vary greatly and they are often extremely painful.
PG is an uncommon ulcerative skin condition which most often affects people in their 40s or 50s. PG rarely affects children and adolescents. It is associated with autoimmune diseases in at least 50 percent of patients.
PG usually starts suddenly, often at the site of a minor injury as a small pustule, red bump or blood blister. The skin breaks down, resulting in an ulcer, or ulcers, which may deepen and widen rapidly. Characteristically, the edge of an ulcer is purple and undermined as it enlarges. PG ulcers are painful.
PG is usually observed on the legs and less typically on the hands. PG lesions can also occur in other organ systems, such as the heart, central nervous system, digestive tract, eyes, liver, spleen, bones and lymph nodes. PG generally responds well to treatment; however, it sometimes recurs or causes scarring.
PG can be treated effectively but complete healing can take months. Treatment is non-surgical. The necrotic tissue is gently removed. Wide surgical debridement is avoided because it may result in enlargement of the ulcer.
Small ulcers are usually treated with topical creams and dressings while large ulcers require immunosuppressive therapy. Tumor necrosis factor inhibitors show promise in treating PG. Surgical procedures are rarely used because they can aggravate the condition.
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.
Small ulcers are best treated with:
• Potent topical steroid creams
• Intralesional steroid injections
• Special dressings (silver sulfadiazine cream or hydrocolloids)
• Oral anti-inflammatory antibiotics such as dapsone or minocycline