Abstract
While topical steroids are an invaluable tool used for the treatment of pruritic rashes, they can also complicate attempts at a definitive diagnosis. The temporal association between steroid use and biopsy must be taken into account when investigating the underlying etiology of such rashes. In patients with a history of dermatologic disease with the onset of a new rash, management should include a biopsy, if deemed necessary for diagnosis, followed by a prescription of topical steroids for symptomatic treatment. A 63-year-old male with a history of psoriasis presented with a new-onset pruritic, erythematous-to-violaceous rash on sun-exposed areas. The final diagnosis of subacute cutaneous lupus erythematosus (SCLE) was delayed due to the use of topical steroids on cutaneous eruptions before presentation in the clinic for biopsy. Diagnosis of SCLE can be difficult, especially for primary care providers who do not see the initial presentation regularly, as cutaneous findings can be variable in presentation. However, recurrent eruptions in similar photo-distributed locations should alert providers of a potential underlying diagnosis and prompt referral for dermatologic evaluation should be suggested. Thorough personal and family history should be taken and photographs of the rash should be documented in the patient's chart for future reference. Ultimately, biopsy is the gold standard diagnostic method for evaluating the etiology of new-onset rash. When there is suspicion of an underlying disease beyond idiopathic contact or irritant dermatitis, a biopsy should be considered as the next best step in management.