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Superficial Fungal Infections

»	What is a dermatophyte?
»	How are superficial fungal infections diagnosed?
»	On a KOH examination, hyphal-like structures arranged in a mosaic pattern are noted. Does this indicate the presence of a dermatophyte?
»	What are the three most commonly used culture media for the growth of dermatophytes?
»	Describe some of the presentations of superficial fungal infections caused by dermatophytes.
»	Which dermatophyte causes the most fungal infections of skin?
»	What is the most common cause of tinea capitis in the United States?
»	Name the four clinical patterns of tinea capitis.
»	What are the types of hair invasion in tinea capitis? What dermatophytes are associated with each type?
»	What is a Wood’s light? What organisms are detected by this exam?
»	How is tinea capitis treated?
»	What is meant by a carrier state in tinea capitis?
»	Name the three types of tinea pedis. Which dermatophyte is most commonly associated with each?
»	What nondermatophyte mold can cause mycotic infections that mimic moccasin-type tinea pedis?
»	What is a dermatophytid reaction?
»	Name and describe the four clinical presentations of onychomycosis.
»	Can other diseases mimic onychomycosis?
»	What is tinea versicolor?
»	How does Malassezia induce both hyperpigmentation and hypopigmentation in the skin?
»	How is tinea versicolor diagnosed? Why is it difficult to culture this organism?
»	Does Malassezia cause any other skin disease?
»	What is tinea nigra?
»	What is a Majocchi’s granuloma?
»	What is piedra?
»	Name the organism most commonly isolated from cutaneous candidiasis.
»	How do candidal infections present clinically?
»	What factors predispose to candidiasis?
»	Which diseases are associated with adult-onset chronic mucocutaneous candidiasis?
»	Name the different classes of oral antifungal agents and their mechanisms of action.
»	Which hepatic cytochrome is affected by itraconazole, ketoconazole, and fluconazole?
»	Which drugs should be used with caution when using ketoconazole, itraconazole, or fluconazole? Why?
»	Which drugs are contraindicated when using azole antifungal agents and why?
»	Which oral antifungal agents can lower cyclosporine levels?
»	Which drugs can affect antifungal drug levels?
»	Which antifungal drugs have a limited spectrum of activity in the treatment of superficial fungal infections?

Describe some of the presentations of superficial fungal infections caused by dermatophytes.

Dermatophyte infections. A, Tinea faciei in a child demonstrating multiple annular scaly lesions of the face. B, Tinea corporis. Annular lesion with scale at the edge and clearing in the central portion of the lesion. C, Tinea cruris. Annular scaly lesion of the groin, note the characteristic sparing of the scrotum. (Panel A courtesy of the William L. Weston, M.D. collection; panel B courtesy of the Fitzsimons Army Medical Center teaching files; panel C courtesy of the Fitzsimons Army Medical Center teaching files.)

Fig. 31.1 Dermatophyte infections. A, Tinea faciei in a child demonstrating multiple annular scaly lesions of the face. B, Tinea corporis. Annular lesion with scale at the edge and clearing in the central portion of the lesion. C, Tinea cruris. Annular scaly lesion of the groin, note the characteristic sparing of the scrotum. (Panel A courtesy of the William L. Weston, M.D. collection; panel B courtesy of the Fitzsimons Army Medical Center teaching files; panel C courtesy of the Fitzsimons Army Medical Center teaching files.)

The superficial dermatophyte infections are classified according to their location on the affected person. This location does not necessarily reveal the identity of the offending organism. The infection will cause the production of scale. The scale may or may not be associated with erythema, vesicles, or annular plaques (Table 31-1, Fig. 31-1).

	Table 31-1. Clinical Presentations of Dermatophyte Infections
	INFECTION		LOCATION
	Tinea capitis		Scalp
	Tinea faciei (see Fig. 31-1A)		Face
	Tinea barbae		Beard
	Tinea corporis (see Fig. 31-1B)		Trunk, extremities
	Tinea cruris (see Fig. 31-1C)		Groin
	Tinea manuum (manus)		Hands
	Tinea pedis		Feet
	Tinea unguium		Nails