Case Challenge: Painless, Erythematous Rash on the Lower Extremities

A 38-year-old woman was referred for evaluation of a leg rash. The rash was first noted approximately 18 months previously and had been slowly increasing in size. She denied itching or pain. Current medications included insulin and atorvastatin. Examination revealed well-demarcated erythematous patches with a yellowish tinge located on both lower legs. No similar lesions were present elsewhere.

Differential diagnosis:

1) Sarcoid

2) Granuloma annulare

3) Discoid lupus

4) Necrobiosis lipoidica

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