Page 182 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 6-7 Integumentary System

TINEA FACIEI AND TINEA CORPORIS

DERMATOPHYTOSES

Dermatophytes are classified in many ways by mycolo-
gists and physicians. One of the simplest classification
systems is based on the natural living conditions of the
studied fungi. Fungi can be classified as zoophilic
(affecting mammals only), anthropophilic (affecting Tinea faciei. Annular patches occur in a
predominantly humans with little transference to other diffuse pattern. Extensive disease may
mammals), or geophilic (predominantly soil fungi that be caused by topical corticosteroid use.
are capable of affecting mammals under the correct
living conditions). This classification is widely used by
physicians, because more complicated categorizations
have minimal impact on the overall therapy and prog-
nosis. Most of these infections are treated with topical
antifungal agents that can be purchased over the counter,
which have very high success rates. Fungal infections of
the hair shaft and nails require systemic therapy for the
highest efficacy of treatment. Topical antifungal agents
do not penetrate the deeper layers of the stratum
corneum, the nail plate, or the hair shaft, and in these
cases systemic antifungals are required for therapy.
Clinical Findings: Superficial fungal infections have
been around for millennia and have been reported in
the literature under various names and descriptions.
Most of the terms used for these infections are based
on the location of the disease. An individual may be
affected by more than one of these types concurrently.
Immunocompetent individuals are less likely than those
who are immunosuppressed to develop widespread
disease.
Tinea corporis (ringworm) is a superficial dermato-
phyte infection of the skin of the trunk or extremities.
It begins as a small red macule or papule and, over time,
spreads out in an annular or polycyclic nature. The
primary morphology of tinea infections is the scaly
patch with a leading trail of scale. On close examina-
tion, one can observe a random amount of hair loss
within the affected area. Most cases are mild and affect
only one or two areas, but some can be widespread and Tinea corporis. Annular scaly patches
can be associated with other forms of tinea such as tinea with a leading edge of scale
unguium. If tinea corporis is left untreated, the fungus
will continue to spread out from the center of each
lesion; lesions can merge into very large patches that
may envelop almost the entire trunk or extremity.
Tinea faciei, as the name implies, occurs on the face.
It appears as annular patches with a leading edge of
scale. The scale is easily scraped off. In adult men, the
term tinea faciei is used to describe disease in regions of
the face other than terminal hair–bearing skin, such as
the beard and scalp. The lesions may converge into
polycyclic patches and are typically pruritic. This form
of superficial fungal infection is commonly seen in chil-
dren. Sleeping in the same bed as pets may increase the
risk of exposure to the causative fungus and the chance
of acquiring any of the superficial fungal infections.
Trichophyton tonsurans is the most likely etiological agent
in North America. along with other Trichophyton species. The infection groin a perfect location for fungal infections. The
Tinea barbae is a fungal infection in the beard region may form boggy, crusted plaques identical to a kerion disease is often very pruritic, and this is what gives it
of postpubertal men. This infection often affects the of the scalp. If the lesions are plaque-like and affect the the vernacular name, “jock itch.” It is seen frequently
skin as well as the hair follicles, and it can appear as hair follicles, systemic therapy is needed. in athletes but is by no means limited to them. Tricho-
red patches with follicle-based pustules. Many fungal Tinea cruris (jock itch) is one of the most easily phyton rubrum and Epidermophyton floccosum are the most
species have been shown to cause this condition, with recognized and prevalent forms of superficial fungal commonly reported etiological agents.
the zoophilic agents being more commonly responsible. infections. The fungus prefers to live in dark, moist Tinea pedis (athlete’s foot) is probably the superficial
Trichophyton verrucosum has been frequently reported, regions of the skin that stay at body temperature. The fungal infection that is best known to members of the

168 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS