Infections |
Atypical mycobacteria |
Bacterial |
- Group A Streptococcus |
- Staphylococcus aureus (especially MRSA) |
- Lyme disease |
- Cutaneous anthrax |
- Syphilis |
- Gonococcemia |
- Ricketsial disease |
- Tularemia |
Deep fungal |
- Sporotrichosis |
- Aspergillosis |
- Cryptococcosis |
Ecthyma gangrenosum (Pseudomonas aeruginosa) |
Parasitic (Leishmaniasis) |
Viral (herpes simplex, herpes zoster [shingles] |
Topical and exogenous causes |
Burns (chemical, thermal) |
Toxic plant dermatitis (poison ivy, poison oak) |
Factitious injury (ie, self-induced) |
Pressure ulcers (ie, bed sores) |
Other arthropod bites |
Radiotherapy |
Vascular occlusive or venous disease |
Antiphospholipid-antibody syndrome |
Livedoid vasculopathy |
Small-vessel occlusive arterial disease |
Venous stasis ulcer |
Necrotising vasculitis |
Leukocytoclastic vaculitis |
Polyarteritis nodosa |
Takayasu's arteritis |
Granulomatosis with polyangiitis and microscopic polyangiitis |
Neoplastic disease |
Leukemia cutis |
Lymphoma (eg, mycosis fungoides) |
Primary skin neoplasms (basal cell carcinoma, malignant melanoma, squamous cell carcinoma) |
Lymphomatoid papulosis |
Other conditions |
Calcific uremic arteriolopathy |
Cryoglobulinemia |
Diabetic ulcer |
Langerhans' cell histiocytosis |
Pemphigus vegetans |
Pyoderma gangrenosum |
Septic embolism |