A Case of Pyoderma Gangrenosum Misdiagnosed as Necrotizing Infection: A Potential Diagnostic Catastrophe

Table 2

Etiologies of skin lesions that can mimic pyoderma gangrenosum.

Infectious	Noninfectious
Atypical mycobacteria	Vascular
Mycobacterium marinum	Polyarteritis nodosa
Mycobacterium ulcerans	ANCA-associated vasculitis
Tuberculosis (cutaneous)	Cryoglobulinemic vasculitis
Leishmaniasis (cutaneous)	Venous stasis
Ecthyma gangrenosum	Thrombophilia
Anthrax (cutaneous)	Antiphospholipid syndrome
Syphilitic gumma	Malignancy
Deep fungal infections	Squamous/basal cell carcinoma
Sporotrichosis	Cutaneous T-cell lymphoma
Zygomycosis	Drug-induced/toxin
Aspergillosis (primary cutaneous)	Cutaneous lupus (hydralazine, TNF-alpha inhibitors)
Penicilliosis (HIV with CD4 < 100/L)	Hydroxyurea
Injection drug use with secondary infection	Venomous bite (brown recluse spider)