A 42-year-old man comes to the office due to an itchy rash. The rash began 3 months ago during the summer and since then has enlarged and spread across his back, chest, and abdomen. The patient has attempted treatment with topical emollients and over-the-counter hydrocortisone cream without relief. Examination reveals scaly, annular plaques, as shown in the exhibit. Potassium hydroxide microscopy of skin scrapings from one of the lesions shows segmented hyphae. In addition to appropriate measures for treatment of the rash, which of the following should be done at this time?

Question

A 42-year-old man comes to the office due to an itchy rash.  The rash began 3 months ago during the summer and since then has enlarged and spread across his back, chest, and abdomen.  The patient has attempted treatment with topical emollients and over-the-counter hydrocortisone cream without relief.  Examination reveals scaly, annular plaques, as shown in the exhibit.  Potassium hydroxide microscopy of skin scrapings from one of the lesions shows segmented hyphae.  In addition to appropriate measures for treatment of the rash, which of the following should be done at this time?

Quizplus · Accepted Answer

11ec25c8_d38f_3f2c_bc81_db6e3a6bd294_MD0003_00 This patient has a chronic skin rash characterized by confluent, scaly, annular plaques. The potassium hydroxide preparation confirms the diagnosis of tinea corporis (TC). TC, sometimes called ringworm, is a superficial dermatophyte infection caused by Trichophyton rubrum or similar species. The fungi thrive in warm, moist areas (eg, shower surfaces, pools, gymnasium mats) and can be transmitted by skin-to-skin contact or contact with animals (eg, cats) or via fomites. Patients with TC are at risk for developing additional foci of infection elsewhere on the body, toes (tinea pedis), groin (tinea cruris), or nails (tinea unguium/onychomycosis) due to autoinoculation. However, extensive, widespread involvement, as in this patient, should raise concern for compromised immunity. Possible contributing factors include diabetes mellitus, systemic glucocorticoid therapy, and HIV infection. In addition to appropriate screening studies, this patient should receive systemic (eg, oral fluconazole) rather than topical antifungal therapy (as would be appropriate for limited, localized disease). (Choice A) Subacute cutaneous lupus erythematosus can present with confluent, annular plaques on the upper body. However, it predominantly involves sun-exposed skin, and itching is uncommon. (Choice B) Skin disorders suggesting underlying hepatitis C include porphyria cutanea tarda (erythema and bullae in sun-exposed areas), lichen planus (pruritic, pink/purple papules and plaques predominantly located at wrists and ankles), and leukocytoclastic vasculitis (palpable purpura). (Choice D) Secondary syphilis is associated with a macular-papular rash that can be scaly but typically involves nearly the entire body, including the palms and soles. (Choice E) Selective IgA deficiency is the most common primary immune deficiency. Most patients are asymptomatic, although they are at increased risk for gastrointestinal and respiratory infections. The risk of dermatophyte infections is not appreciably increased. Educational objective: Patients with tinea corporis are at risk for developing additional foci of infection elsewhere on the body, toes, groin, or nails due to autoinoculation. Patients with compromised immunity due to diabetes mellitus, systemic glucocorticoid therapy, or HIV infection can develop extensive, widespread involvement.

A 42-Year-Old Man Comes to the Office Due to an Itchy