Pyoderma

Background

• 1/100,000 people per year in US, primarily 40s-50s yoa
• Dysfunction of activated neutrophils
• >50% associated with systemic disease:
  • IBD
  • Polyarthritis, sero-negative and -positive
  • Leukemia
  • Less commonly psoriatic arthritis, OA, RA, spondyloarthopathy, hepatitis, PBC, myelomas, SLE, Sjogren

Clinical Features

• Extracutaneous manifestations (due to sterile neutrophilic infiltrates)
  • Culture-negative pulmonary infiltrates most common
  • CV, CNS, GI, eyes, liver, spleen, bones, LNs
• Features
  • 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

Travel-related skin conditions

• Papules
  • Insect bites
  • Scabies
  • Seabather's eruption
  • Cercarial dermatitis (Swimmer's Itch)
• Macular
  • Chikungunya
• Sub Q Swelling and Nodules
  • Myiasis
  • Tungiasis
  • Loa loa
  • African Trypanosomiasis
  • Onchocerciasis
• Ulcers
  • Tropical pyoderma
  • Leishmaniasis
  • Mycobacterium marinum
  • Buruli ulcer
  • Dracunculiasis (Guinea Worm disease)
• Linear and Migratory Lesions
  • Cutaneous larvae migrans
  • Photodermatitis

See also domestic U.S. ectoparasites

See Also

• Travel Medicine