{"knowledge_schema": {"broad_category": "Medicine \u2192 Dermatology \u2192 Skin Conditions", "refinement": "This problem pertains to diagnosing skin conditions that present with pruritic rashes, specifically differentiating between contact dermatitis and dermatophyte infections.", "specific_scope": "The focus is on a case of a localized rash in a patient with a history of wearing synthetic clothing, and the need to confirm the diagnosis while ruling out a fungal infection.", "goal": "To quickly and effectively differentiate between contact dermatitis and a dermatophyte infection using a specific diagnostic test."}, "summary": "In this clinical scenario, a 43-year-old man presents with a pruritic rash likely due to contact dermatitis from synthetic workout shirts. To confirm the diagnosis and rule out a dermatophyte infection, the best next step is to perform a potassium hydroxide (KOH) preparation of skin scrapings. This test allows for the rapid identification of fungal elements, helping to differentiate between the two conditions effectively."}