Pyoderma gangrenosum

Background

• 1/100,000 people per year in US, primarily 40s-50s year of age
• Dysfunction of activated neutrophils
• >50% associated with systemic disease:
  • IBD
  • Polyarthritis, sero-negative and -positive
  • Leukemia
  • Less commonly psoriatic arthritis, osteoarthritis, RA, spondyloarthopathy, hepatitis, primary biliary cirrhosis, multiple myeloma, SLE, Sjogren

Clinical Features

• Extracutaneous manifestations (due to sterile neutrophilic infiltrates):
  • Culture-negative pulmonary infiltrates most common
  • cardiovascular, CNS, GI, eyes, liver, spleen, bones, lymph nodes
• Initial lesion: bite-like, small, red papule or pustule (many patients attribute spider bite)
• Changes into larger, ulcerative lesion
• Two primary variants:
  • Classic ulcerative form - usually on legs, deep ulceration, violaceous border along ulcer bed
  • Superficial, atypical form - hands/forearms/face, vesiculopustular
  • Less common variants: 1) Peristomal pyoderma, 2) Genital pyoderma (must differentiate from STI), 3) Pyostomatitis vegetans (intraoral)

Differential Diagnosis

• Systemic diseases
  • Neutrophilic dermatoses (Sweet, Behcet's disease, etc.)
  • Calciphylaxis - very important to differentiate due to treatment
  • Arterial/venous insufficiency
  • Blastomycosis
  • Hidradenitis suppurative
  • TB gumma, mycobacterial infections
  • Malignancy (squamous cell)
  • Vasculitis
  • Ecthyma gangrenosum (pseudomonas)

Travel Related Skin Conditions

Papules

• Insect bites
• Scabies
• Seabather's eruption
• Cercarial dermatitis (Swimmer's Itch)

Sub Q Swelling and Nodules

• Myiasis
• Tungiasis
• Loa loa
• African Trypanosomiasis
• Onchocerciasis

Ulcers

• Pyoderma
• Leishmaniasis
• Mycobacterium marinum

Linear and Migratory Lesions

• Cutaneous Larvae Migrans
• Photodermatitis

Evaluation

• Diagnosis of exclusion
• No specific criteria
• CBC, CMP, UA, hepatitis profile, coags, VDRL
• Autoimmune labs: ANCA, antiphospholipid antibody
• Tissue cultures (comprehensive, all organisms)

• • Coags
  • Anti-phospholipid antibody
  • Referral for heme malignancy workup
  • Referral for IBD workup
• CXR if systemic disease suspected

Management

• Nonsurgical management
  • Necrotic tissue should be gently removed
  • Wide surgical debridement results in enlargement of ulcer
• Medical management
  • Small ulcers
    • Topical steroids and/or steroid injections, silvadene compression dressings
    • Dapsone or minocycline PO
  • Severe ulcers
    • Corticosteroids
    • Immunologic treatment/biologics
    • IVIG, plasmapheresis

Disposition

• Usually discharge with derm and/or surgery follow-up and referral for IBD and malignancy workup

See Also

• Travel Medicine

References

Authors

Claire, Kevin Lu, Ross Donaldson, Neil Young, Daniel Ostermayer