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A 55-year-old woman with a history of longstanding diabetes mellitus and previous history of left foot osteomyelitis presented with a 2-week history of lower extremity and bilateral hand skin changes.

What is the diagnosis?
Scabies
The rash was initially concerning for gangrene. Microscopic examination of the patient's skin by dermatology revealed a significant burden of scabies mites, making her diagnosis consistent with crusted scabies, formerly known as Norwegian scabies. Crusted scabies, formerly known as Norwegian scabies, is a more severe form of the infection often associated with immunosuppression.

The disease can be effectively treated with a number of medications. Permethrin cream is the most effective, but expensive compared to other treatments. Crotamiton is less effective, but also nontoxic and soothing. Ivermectin may be used orally and topically. Treatment with lindane preparations has fallen out of favor due to high toxicity and parasite resistance. In order to prevent re-infection, the host's contacts are also often treated.

The patient was treated with permethrin cream as an inpatient as well as PO ivermectin, with which her rash demonstrated significant improvement. She was discharged with instructions to repeat a treatment with permethrin cream in a week as well as ivermectin weekly for 3 additional weeks. She was also given triamcinolone cream to treat the inflammatory component of her rash.