Tinea corporis is a dermatophytosis Overview of Dermatophytoses Dermatophytoses are fungal infections of keratin in the skin and nails (nail infection is called tinea unguium or onychomycosis). Symptoms and signs vary by site of infection. Diagnosis is by... read more that causes pink-to-red annular (O-shaped) patches and plaques with raised scaly borders that expand peripherally and tend to clear centrally. A rare variant form appears as nummular (circle- or round-shaped) scaling patches studded with small papules or pustules that have no central clearing. Common causes are Trichophyton mentagrophytes, T. rubrum, and Microsporum canis.
The border is raised and scaly and has visible tiny pustules.
© Springer Science+Business Media
Both lesions are due to tinea corporis. The lesion on the right shows typical peripheral scale and slight central lesion clearing.
© Springer Science+Business Media
© Springer Science+Business Media
This photo shows a well-demarcated, scaly, erythematous plaque characteristic of tinea corporis. Postinflammatory hyperpigmentation makes the center appear less clear than on light skin.
Image courtesy of Karen McKoy, MD.
Diagnosis of Tinea Corporis
Clinical evaluation
Potassium hydroxide wet mount
Differential diagnosis of tinea corporis includes
Treatment of Tinea Corporis
Topical or oral antifungals
( See table: Options for Treatment of Superficial Fungal Infections* Options for Treatment of Superficial Fungal Infections* 
.)
Treatment of mild-to-moderate lesions is an imidazole, ciclopirox, naftifine, or terbinafine in cream, lotion, or gel. The drug should be rubbed in 2 times a day continuing at least 7 to 10 days after lesions disappear, typically at about 2 to 3 weeks.
Extensive and resistant lesions occur in patients infected with T. rubrum and in people with debilitating systemic diseases. For such cases, the most effective therapy is oral itraconazole 200 mg once a day or terbinafine 250 mg once a day for 2 to 3 weeks.
Key Points
Tinea corporis typically causes pink-to-red annular (O-shaped) patches and plaques with raised scaly borders that expand peripherally and tend to clear centrally.
Diagnose based on appearance and potassium hydroxide wet mount.
If mild-to-moderate, treat using an imidazole, ciclopirox, naftifine, or terbinafine cream, lotion, or gel applied 2 times a day for at least 7 to 10 days after lesions disappear.
