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Chapter 21. Dermatophytosis

Definition

An inflammatory process caused by superficial fungi, i.e., fungi situated superficially in the cornified layer and in other cornified structures, and expressed clinically as smooth-surfaced papules, scaly papules, scaly plaques, nodules, pustules, vesicles, and bullae. The papules, pustules, and nodules may be centered in follicles (Majocchi’s granuloma). Lesions may occur on any anatomic site, but particularly on the scalp (tinea capitis), inguinal region (tinea cruris), hands (tinea manum), feet (tinea pedis), and nails (onychomycosis).

Adjunctive Diagnostic Test

Wood’s lamp examination enables infection by microsporum species to be confirmed. Examination by conventional microscopy of scrapings of skin and clippings of nails in KOH preparations reveals septate hyphae. Precise identification of the type of dermatophyte requires culture on Sabouraud’s dextrose agar.

Course

Dermatophytosis is common, especially the scaly papules, papulovesicles, and vesicles of “athlete’s foot.” As most people who have that condition know, in the absence of treatment, its lesions come and go for years. Some expressions of dermatophytosis are self-limited, such as the infundibulocentric lesions of Majocchi’s granuloma and, episodically, of kerion. Other manifestations, however, are tenaciously persistent, like onychomycosis and dermatophytosis in an immunosuppressed patient. In that latter circumstance, lesions of a superficial fungal infection may be widespread and chronic.

Integration: Unifying Concept

All of the features morphologic of dermatophytosis, among them, macules, papules, nodules, pustules, vesicles, and bullae, represent the effects of products of dermatophytes that reside in corneocytes within the skin, to wit, the stratum corneum, the cornified layer of the infundibulum, inner sheath, hair shaft, and nail plate. The range of changes histopathologic in dermatophytosis is great, among them spongiotic dermatitis, intraepidermal vesicular dermatitis, psoriasiform dermatitis, and suppurative infundibulitis, the latter often expressing itself clinically as Majocchi’s granuloma?a misnomer because the process is not fundamentally granulomatous, but suppurative infundibulitis. Dermatophytic involvement of hair shafts leads to breakage of them, and involvement of nail plates to dystrophy of them.

Therapy

Tinea pedis: Topical antimycotics. Onychomycosis: Oral antimycotics (griseofulvin, triazoles, terbinafine). Tinea capitis: Griseofulvin, oral azoles, or allylamine derivatives. Tinea corporis: Topical antimycotics. If widespread, treatment with orally administered antimycotics.

Distribution

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Fig. 21-1

Scaly lesions of tinea capitis.


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Fig. 21-2

Alopecia with scales.


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Fig. 21-3

Alopecia with large erythematous plaque and widespread macules and papules (id reaction).


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Fig. 21-4

Papules and plaques in figurate arrangement.


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Fig. 21-5

Plaque with annular border showing scales.


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Fig. 21-6

Papules and plaques with ill-defined borders on the forehead, nose, and cheeks.


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Fig. 21-7

Erythematous scaly papules and nummular plaques.


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Fig. 21-8

Erythematous scaly circinate plaques.


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Fig. 21-9

Arciform scaly plaques.


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Fig. 21-10

Scaly palms.


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Fig. 21-11

Erythematous scaly plaque with scalloped border.


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Fig. 21-12

Erythematous scaly papules and plaques, some of them with arcuate and polycyclic outlines.


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Fig. 21-13

Patches with many papules near and at the border.


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Fig. 21-14

Annular scaly plaque.


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Fig. 21-15

Infundibular papules and pustules surrounded by erythema, the scaly periphery being scalloped (Majocchi’s granuloma).


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Fig. 21-16

Maceration and scales, some of them in the form of a collarette.


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Fig. 21-17

Thickened yellow nail plate with a ragged distal margin.


Configuration

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Fig. 21-18

Erythematous scaly papules arranged in an annulus.


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Fig. 21-19

Papules and vesicles covered by scales and crusts, all of which combined have created a serpiginous outline.


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Fig. 21-20

Labyrinthine arrangement of scaly papules.


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Fig. 21-21

Scaly plaques in a pattern of concentric rings.


Individual Lesions

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Fig. 21-22

Erythematous plaque topped by pustules.


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Fig. 21-23

Crowded erythematous papules and pustules in nummular shape on the side of the face; nodules on the jawline and chin.


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Fig. 21-24

Large erythematous nummular plaque surmounted by innumerable pustules.


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Fig. 21-25

Papules and pustules on and within a circle.


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Fig. 21-26

Plaque with figurate outline and an elevated border composed of papules, pustules, and crusts.


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Fig. 21-27

Infundibulocentric scaly papules, some of them eroded, with diffuse hyperpigmentation (Majocchi’s granuloma).


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Fig. 21-28

Partially alopecic erythematous tumor with a papillated surface (kerion).


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Fig. 21-29

Patch of alopecia with scales.


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Fig. 21-30

Plaque with draining sinuses and crusts (kerion).


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Fig. 21-31

Closely-set nodules, pustules, and draining sinuses in a boggy mass (kerion).


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Fig. 21-32

Tense vesicles and vesiculopustules, some of them grouped.


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Fig. 21-33

Vesicles, a tense bulla, and scale-crusts.


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Fig. 21-34

Vesicles and pustules.


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Fig. 21-35

Scaly erythematous plaque with sharply defined scalloped borders (moccasin distribution).


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Fig. 21-36

Wedge-shaped onycholysis and subungual hyperkeratosis (distaltype of onychomycosis).


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Fig. 21-37

Chalky white discoloration of the distal nail plate.


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Fig. 21-38

Yellow-white discoloration of the distal two-thirds of the nail plate and subungual hyperkeratosis.


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Fig. 21-39

Severely dystrophic nails and scales in foci on volar skin.


New! Additional Images

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Fig. 21-40

Large somewhat annular plaques with scale-crust at their margin indicate likelihood of immunosuppression. A pink papule at the jaw line is an early lesion. Pigmented papules are Miescher’s nevi.


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Fig. 21-41

All of the lesions shown here, namely, papules, nodules, erosions, and ulcers, are secondary to suppurative infundibulitis induced by a dermatophyte, i.e., “sycosis barbae.”


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Fig. 21-42 A

Papules have become confluent to form ill-defined plaques whose border is scalloped.


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Fig. 21-42 B

Papules have become confluent to form ill-defined plaques whose border is scalloped.


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Fig. 21-43

The annular plaque is covered by scale-crusts. As the lesion advanced outward, a “zone of clearing” was left in the center.


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Fig. 21-44

The remarkable figurate pattern came into being by virtue of the peculiar growth of the fungus responsible for it.


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Fig. 21-45

Nummular scaly plaque. Note that the border of the lesion is slightly scalloped.


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Fig. 21-46

The figurate pattern produced by a fungus is accentuated by scale on the inner aspect of arc-like ridges.


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Fig. 21-47

The bizarre-shaped plaque is made up largely of numerous scaly, crusted papules. Note “zones of clearing” in some loci.


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Fig. 21-48

The arciform plaques have a raised border. Scattered hemorrhagic crusts are secondary to excoriation. Signs of onychomycosis also are apparent.


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Fig. 21-49

This scaly palm, whose flexural folds are accentuated by the disease, is accompanied by signs ofonychomycosis.


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Fig. 21-50

Tinea manum typified by diffuse redness and by accentuation of scaliness in flexural creases. Collarettes of scale are a sure sign of loss of a cap of parakeratosis above a focus of spongiosis.


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Fig. 21-51

The constellation of destruction of the distal part of the nail plate, onycholysis, and subungual keratosis are evidences of onychomycosis.


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Fig. 21-52

Papules and plaques, some with accentuation of skin markings (lichen simplex chronicus), are those of dermatophytosis, the clue being papules in arcuate and serpiginous array and infundibulocentricity (Majocchi’s granuloma).


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Fig. 21-53

The moccasin distribution of a plaque covered by ichthy osiform scale is one of many manifestations of dermatophytosis. The fissure, a crack in the hyperkeratotic surface, extends to the papillary dermis.


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Fig. 21-54

The serrated appearance of the distal end of the nail and the subungual keratosis are evidences of onychomycosis.


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Fig. 21-55 A

This nummular patch of alopecia covered by furfuraceous scale resulted from an infection of stratum corneum and hair shafts by a fungus.


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Fig. 21-55 B

This nummular patch of alopecia covered by furfuraceous scale resulted from an infection of stratum corneum and hair shafts by a fungus.


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Fig. 21-56

Nummular scaly patches of alopecia are an expression of an infection by a fungus.


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Fig. 21-57 A

Annular, arcuate, and polycyclic scaly lesions are typical of one manifestation of fungal infection. A child such as this one with widespread lesions could be immunosuppressed, but need not be.


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Fig. 21-57 B

Annular, arcuate, and polycyclic scaly lesions are typical of one manifestation of fungal infection. A child such as this one with widespread lesions could be immunosuppressed, but need not be.


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Fig. 21-58

Kerion with secondary cellulitis, the former being an exuberant response to dermatophytosis and the latter a complication by gram positive bacteria.


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Fig. 21-59

Majocchi’s granuloma, a suppurative infundibulitis consequent to infection of hair shaft and inner sheath by dermatophytes.