Etiology

Mucosal

• Behcet’s Disease (see Behcet’s Disease, [[Behcets Disease]]): genital and oral ulcers
• Chronic Graft vs Host Disease (GVHD) (see Graft vs Host Disease, [[Graft vs Host Disease]])
• Chronic Granulomatous Disease (CGD) (see Chronic Granulomatous Disease, [[Chronic Granulomatous Disease]])
• Cytomegalovirus (CMV) (see Cytomegalovirus, [[Cytomegalovirus]])
• Erythema Multiforme (see Erythema Multiforme, [[Erythema Multiforme]])
• Hand, Foot, and Mouth Disease (see Hand, Foot, and Mouth Disease, [[Hand, Foot, and Mouth Disease]])
• Herpes Simplex Virus (HSV) (see Herpes Simplex Virus, [[Herpes Simplex Virus]])
• Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]]): acute infection
• Inflammatory Bowel Disease (IBD) (see Inflammatory Bowel Disease, [[Inflammatory Bowel Disease]])
• Langerhans Cell Histiocytosis (see Langerhans Cell Histiocytosis, [[Langerhans Cell Histiocytosis]])
• Reiter’s Syndrome (see Reiter’s Syndrome, [[Reiters Syndrome]]): aka Reactive Arthritis
• Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis (see Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis, [[Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis]])
• Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus, [[Systemic Lupus Erythematosus]])
• Vesicular-Bullous Skin Disease (see Vesicular-Bullous Skin Lesions, [[Vesicular-Bullous Skin Lesions]])

Face

• Herpes Simplex Virus (HSV) (see Herpes Simplex Virus, [[Herpes Simplex Virus]]): especially peri-oral and anogenital

Hands and Feet

• Buerger’s Disease (see Buerger’s Disease, [[Buergers Disease]])
• Raynaud’s Phenomenon (see Raynaud’s Phenomenon, [[Raynauds Phenomenon]])

Lower Legs

• Acral Angiodermatitis
• Anti-Phospholipid Antibody Syndrome (see Anti-Phospholipid Antibody Syndrome, [[Anti-Phospholipid Antibody Syndrome]])
• Cholesterol Emboli Syndrome (see Cholesterol Emboli Syndrome, [[Cholesterol Emboli Syndrome]])
• Cryoglobulinemia (see Cryoglobulinemia, [[Cryoglobulinemia]])
• Cryofibrinogenemia
• Hemoglobinopathy
• Kaposi Sarcoma (see Kaposi Sarcoma, [[Kaposi Sarcoma]])
• Necrobiosis Lipoidica
• Panniculitis
• Peripheral Neuropathy (see Peripheral Neuropathy, [[Peripheral Neuropathy]])
• Vasculitis (see Vasculitis, [[Vasculitis]]): small and medium vessel vasculitis

Generalized

• Calciphylaxis (see Metastatic Calcification, [[Metastatic Calcification]])
• Dimorphic Fungal Infection
  • Blastomycosis (see Blastomycosis, [[Blastomycosis]])
  • Coccidioidomycosis (see Coccidioidomycosis, [[Coccidioidomycosis]])
  • Histoplasmosis (see Histoplasmosis, [[Histoplasmosis]])
  • Sporotrichosis (see Sporotrichosis, [[Sporotrichosis]])
• Leishmaniasis (see Leishmaniasis, [[Leishmaniasis]])
• Lymphoma (see Lymphoma, [[Lymphoma]])
• Pyoderma Gangrenosum: most commonly involves legs

Variable

• Ecthyma Gangrenosum (see Ecthyma Gangrenosum, [[Ecthyma Gangrenosum]]): in cases due to Staph
• Hydroxyurea (see Hydroxyurea, [[Hydroxyurea]])
• Liveoid Vasculopathy: venous hypertension
• Peripheral Vascular Disease (see Peripheral Vascular Disease, [[Peripheral Vascular Disease]]): venous or arterial
• Squamous Cell Carcinoma
• Trauma/Pressure Ulcer

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References

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