Tinea infections are caused by dermatophytes, except for tinea versicolor, which is caused by yeasts in the Malassezia genus. If available, potassium hydroxide preparation should be performed to confirm diagnosis of tinea capitis or onychomycosis. In some cases, fungal culture, UV light examination, or periodic acid–Schiff stain can be helpful. Topical drugs are effective for tinea corporis, tinea cruris, and tinea pedis. Tinea incognito is an atypical presentation that usually requires systemic treatment. Management of tinea capitis always requires oral drugs. Oral drugs are preferred for onychomycosis treatment but should not be prescribed without confirmation of fungal infection. Localized cases of tinea versicolor can be managed with topical drugs, but oral drugs might be needed for severe, widespread, or recurrent cases. Warts are superficial human papillomavirus infections. Common treatments include irritant, destructive (eg, cryotherapy), immune stimulant (eg, intralesional Candida antigen), and debridement and excision methods. Scabies infestation results in intensely itchy papules, nodules, or vesicles. Mites and burrows on the skin are pathognomonic but difficult to identify. Dermoscopy, particularly with UV light, can make identification easier. Topical permethrin and oral ivermectin are two of the most commonly used treatments. All household and close contacts should be treated regardless of the presence or absence of symptoms.

Case 3. CK is a 7-year-old patient brought to your office by his father because of hair loss. On physical examination, you note circular areas of broken hair with white scales. It appears that CK has been scratching these areas. You note posterior cervical lymphadenopathy on visual inspection and palpation.