Pyoderma gangrenosum - Anogenital in
The two primary variants are a classic ulcerative form, which often involves the lower extremities, and a vesicobullous form, which is more superficial and tends to occur on the upper extremities, including hands. Fever, toxicity, and pain can be associated with the onset of PG. Extracutaneous manifestations may take the form of sterile neutrophilic abscesses, such as in the lungs, heart, gastrointestinal tract, liver, eyes, central nervous system, and lymphatic tissue.
Though the exact cause is unknown, neutrophil dysfunction, inflammation, and genetics are all thought to play a role. Additionally, PG has associations with a number of systemic illnesses. In about 50% of cases, there is an association between PG and systemic diseases such as ulcerative colitis, Crohn disease, arthritis, myeloma, leukemia, monoclonal gammopathy, granulomatosis with polyangiitis (formerly known as Wegener granulomatosis), collagen vascular disease, and Behçet disease, among other disorders. Surgery by itself can be a precipitating cause. Levamisole-contaminated cocaine has been associated with PG lesions ranging from vesicopustules to bullae to larger ulcers; most patients demonstrated positivity for antiphospholipid or anticardiolipin antibodies.
PG tends to be self-limited. First-line therapies are widely accepted, while alternative therapeutic recommendations are largely based on anecdotal evidence. Surgical intervention is a common exacerbating factor because PG demonstrates pathergy, a phenomenon by which skin trauma can lead to worsening disease.
L88 – Pyoderma gangrenosum
74578003 – Pyoderma gangrenosum
Differential Diagnosis & Pitfalls
- Infectious causes of ulcers can mimic PG. PG is in the family of neutrophilic skin disorders, which includes acute febrile neutrophilic dermatosis, subcorneal pustular dermatosis, and Behçet disease. As many infectious processes can cause a similar picture (eg, progressive bacterial synergistic gangrene, North American blastomycosis, other deep fungal infections, amebiasis, sporotrichosis, atypical mycobacterial infection), PG is a diagnosis of exclusion.
- Calciphylaxis – can present as a painful ulcer on the penis
- Primary syphilis
- Chancroid – usually present around genital skin
- Herpes simplex virus (HSV) – usually grouped, punched-out erosions
- Ecthyma gangrenosum
- Factitial ulcer – sharp geometric borders
- Squamous cell carcinoma
- Traumatic ulceration
- Tertiary syphilis
- Insect or spider bite
- Acute febrile neutrophilic dermatosis
- Pyodermatitis vegetans
Drug Reaction Data