C h a p t e r 4 6
Disorders of Skin Integrity and Function
1155
of a pustular, scaly, round patch with broken hairs. A
secondary bacterial infection is common and may lead
to a painful, circumscribed, boggy, and indurated lesion
called a
kerion
. The highest incidence is among children
and farmers who work with infected animals.
Both the noninflammatory and inflammatory forms
of tinea capitis are treated with oral griseofulvin or syn-
thetic antifungal agents that penetrate the hair shafts.
5–7
Topical ointments or shampoos are sometimes indicated
in addition to oral medications, both to decrease the
spore population and to protect household members.
Because of the lower fatty acid content in the sebum of
young children, several of the topical antifungal agents
are prepared with fatty acid bases. Wet packs, medicated
shampoos, steroids, and antibiotics may be prescribed
for secondary infections that occur.
Tinea of the Foot and Hand.
Tinea pedis (athlete’s
foot) is the most common fungal dermatosis, primar-
ily affecting the spaces between the toes, the soles, or
the sides of the feet (Fig. 46-3). The lesions vary from
a mildly scaling lesion to a painful, exudative, erosive,
inflamed lesion with fissuring. Lesions often are accom-
panied by pruritus, pain, and foul odor. Mild forms are
more common during dry environmental conditions.
Exacerbations occur as a result of hot weather, sweat-
ing, and exercise or when the feet are exposed to mois-
ture, occlusive shoes, and communal swimming.
Tinea of the hand (
Tinea manus
) is usually a second-
ary infection with tinea pedis as the primary infection.
In contrast to other skin disorders, it usually occurs
only on one hand. The characteristic lesion is a blister
on the palm or finger surrounded by erythema. Chronic
lesions are scaly and dry. Cracking and fissuring may
occur. The lesions may spread to the plantar surfaces of
the hand. If chronic, tinea manus may lead to tinea of
the fingernails.
Simple forms of tinea pedis and tineamanus are treated
with topical applications of antifungals. Complex cases
are treated with oral antifungals. Other treatment and
preventive measures include careful cleaning and drying
of affected areas.
Tinea of the Nails.
Tinea unguium
is a dermatophyte
infection of the nails. It is a subset of a condition called
onychomycosis,
which includes dermatophyte, nonder-
matophyte, and candidal infections of the nails.
The infection often begins at the tip of the nail, where
the fungus digests the nail keratin (Fig. 46-4). In some
cases, it may be caused by a crushing injury to a toenail
or the spread of tinea pedis. Initially, the nail appears
opaque, white, or silver. The nail then turns yellow or
brown. The condition often remains unchanged for
years. During this time it may involve only one or two
nails and may produce little or no discomfort. As the
infection spreads, the nail thickens and cracks and the
nail plate separates from the nail bed.
The standard for the diagnosis of fungal nail dis-
ease is a positive result on microscopic examination
and culture of nail clippings with subungual debris.
Persons with minimal toenail involvement and no
associated symptoms may not require treatment.
FIGURE 46-2.
Ringworm or tinea of the scalp (tinea capitis)
caused by the Microsporum species. (From the Centers for
Disease Control and Prevention Public Health Image Library.
No. 2940. Courtesy of Dr. Lucille K. Georg.)
FIGURE 46-3.
Chronic tinea of the sole caused by
Trichophyton rubrum. (From the Centers for Disease Control
and Prevention Public Health Image Library. No. 15441.)
FIGURE 46-4.
Onychomycosis due to Trichophyton rubrum,
right and left great toes. (From the Centers for Disease Control
and Prevention Public Health Image Library. No. 579. Courtesy
of Edwin P. Ewing, Jr.)
