Pyoderma gangrenosum in Adult
The 2 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. Rarely, PG can involve the eyes as well. 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.
Necrotizing neutrophilic dermatosis describes a subset of patients with severe acute febrile neutrophilic dermatosis (Sweet syndrome) or PG who develop, in addition to their cutaneous disease, fever, leukocytosis (or a leukemoid reaction), and features of shock. Skin pain is a prominent symptom. Additionally, soft tissues underlying areas of skin involvement may be affected with neutrophilic infiltrates and necrosis.
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, metabolic syndrome, and Behçet disease, among other disorders, including genetic conditions (see Look For). 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
- Infection – 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. If a patient has traveled to tropical countries within the last 6 months, diagnoses such as cutaneous leishmaniasis, tropical ulcer, and Buruli ulcer must be considered.
- Calciphylaxis – Rapidly progressive, can be associated with eschars.
- Chancroid – Usually present around genital skin.
- Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
- Herpes simplex virus (HSV) – Usually grouped, punched-out erosions.
- Ecthyma gangrenosum
- Squamous cell carcinoma – Associated with keratotic plaques.
- Venous or arterial ulcerations
- Martorell hypertensive leg ulcer
- Granulomatosis with polyangiitis
- Traumatic ulceration
- Xylazine-induced skin ulcer
- Necrobiosis lipoidica – Usually associated with atrophic plaques.
- Necrotizing fasciitis – Necrotizing neutrophilic dermatosis may mimic necrotizing fasciitis. Histopathologic findings and blood and tissue cultures are useful diagnostically.
- Tertiary syphilis
- Factitial ulcer – Sharp geometric borders.
- Factitial panniculitis
- Insect or spider bite
- Mycobacterium marinum infection
- Impetigo (bullous, non-bullous)
- Acute febrile neutrophilic dermatosis
Drug Reaction Data