Table 4.

SSTI mimetics

Syndrome	Cause(s)	Characteristic features
Pyoderma gangrenosum	Autoimmune conditions, hematologic malignancies, idiopathic in up to 50 %	Tender papulopustules with surrounding erythema that develop into ulcers with purulent base.Typically on lower extremities, tend to be painful with undermined edges. Heaped up borders with gun-metal gray color. Necrosis extends with surgical intervention
Lymphedema/chronic venous stasis	Multiple—cardiac dysfunction, renal failure, lymph node surgeries, lymph node destruction (filariasis), varicose veins	In volume overload states, often symmetric and bilateral
Deep venous thrombosis	Thrombosis	Can be hard to differentiate on exam alone, may be suggested by history—i.e. prolonged immobility, genetic risk factors
Loxoscelism	Brown recluse spider bite	Retiform purpura