What is Pyoderma gangrenosum

Pyoderma gangrenosum is an uncommon, ulcerative cutaneous condition of uncertain etiology (cause). It is associated with systemic autoimmune related diseases in at least 50% of patients who are affected. The diagnosis is made by excluding other causes of similar-appearing cutaneous ulcerations, including infection, malignancy, vasculitis, collagen vascular diseases, diabetes, and trauma. In a process termed pathergy, new ulcerations may occur after trauma or injury to the skin in 30% of patients who already have pyoderma gangrenosum. The prognosis of pyoderma gangrenosum is generally good; however, the disease may recur, and residual scarring is common. Pain is a common complaint of patients and may require narcotics.

Pyoderma gangrenosum is a rare, destructive inflammatory skin disease of which a painful nodule or pustule breaks down to form a progressively enlarging ulcer. Lesions may occur either in the absence of any apparent underlying disorder or in association with other diseases, such as ulcerative colitis, Crohn’s disease, polyarthritis (an inflammation of several joints together), gammopathy, vasculitis, leukemia, and other conditions.[1][2][3] Each year in the United States, pyoderma gangrenosum occurs in about 1 person per 100,000 people.[1]

Pyoderma gangrenosum belongs to a group of autoinflammatory skin diseases called neutrophilic dermatoses.[2][3][4] Neutrophils are a type of white blood cell or leukocyte which form an early line of defense against bacterial infections.[5] Ulcerations associated with pyoderma gangrenosum may occur after trauma or injury to the skin, a process called pathergy.[1][2] Treatment involves wound care and the use of anti-inflammatory agents, including antibiotics, corticosteroids, immunosuppressants, and biologics.[1][2][3][4]

This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
https://rarediseases.info.nih.gov/diseases/7510/pyoderma-gangrenosum