Generalized rash and pruritus in a 58-year-old woman.

Although allergists often evaluate rashes associated with allergic, IgE mediated etiologies, it is important to consider a wide range of differential diagnoses that includes inflammatory, infectious, and autoimmune etiologies. The case of a 58-year-old woman with a 1-year history of progressive pruritic rash that did not improve with topical creams and steroids is presented. The patient did not state any other symptoms, and a physical examination was notable for a widespread rash. After a detailed evaluation of the rash, a differential diagnosis was made, and results of a skin biopsy confirmed a specific diagnosis. Even in the context of a medical history of atopy, one must consider nonallergic causes of rash, including abnormal presentations of systemic conditions. It is important to determine the specific etiology of the rash because this will dictate treatment and prognosis and/or complications of the disease associated with the skin manifestations.