A 26-year-old female presents complaining of a rash on her right wrist that has been present for two weeks. It is extremely itchy and has been gradually enlarging. On examination, there is an annular lesion with a central clearing. The lesion is scaly and excoriated with raised edges.
1. What is the diagnosis?
2. What is the differential diagnosis of this lesion?
3. What is the treatment?
1. Tinea corporis (i.e., ringworm)
2. The differential diagnosis should include impetigo, psoriasis, erythema multiforme, pityriasis rosea, nummular eczema, granuloma annulare, and seborrheic dermatitis.
3. Topical antifungals, such as ketoconazole, terbinafine, and clotrimazole work well. Treatment should ideally be continued for one to two weeks after clinical resolution of the rash, which can take up to four weeks.
