The Journal of the Arkansas Medical Society Med Journal March 2020 Final 2 | Page 20

Derm Dilemma
Special Section: Short Dermatological Cases
by Sam Schach, Biomedical Engineering Student, U of VA.
Tinea Faciei
A
23-month-old girl presents with a six-
week history of worsening, erythema-
tous, annular, and scaling plaques of
the face. The patient’s mother
applied an over-the-counter anti-fun-
gal cream for three days without res-
olution. They then visited their pedia-
trician, who prescribed triamcinolone
0.025% cream. The patient’s mother
has been applying the cream twice a
day for four weeks. The rash has con-
tinued to spread.
mount depicted is positive which indicates
a fungal infection. This proves the diagnosis
to be tinea faciei. Granuloma annulare (GA)
A common mantra in dermatology
is “if it scales, scrape it.” When a scaling
rash is seen and tinea is a possibility,
a skin scraping for a KOH test is taken
from the scale on the leading edge of
the advancing border of the rash. The
KOH test is used to determine if the
rash is fungal in origin. KOH dissolves
keratinocyte skin cells in order to bet-
ter expose the dermatophyte hyphae
for microscopic diagnosis. Early or less
severe cases of tinea may be managed
with topical antifungals whereas more
severe or widespread cases are best
treated with oral antifungals. When
treated appropriately, tinea faciei typi-
cally resolves without scarring.
Provided this clinical image and
photomicrograph of a potassium hy-
droxide (KOH) mount, what is the most
appropriate next step in management
of this patient?
A) The KOH test is negative. A skin bi-
opsy should be taken and autoim-
mune serologies should be drawn,
as this patient most likely suffers
from neonatal lupus erythemato-
sus. Evaluate the mother for auto-
antibodies and the child for heart
block.
B) The KOH test is positive. The patient
has tinea faciei. The triamcinolone
should be discontinued, and oral
antifungal therapy initiated.
Answer: B. has a predilection for the extensor surfaces
of the joints, rarely presents on the face, and
does not have surface scale. Neonatal lupus
has a similar clinical appearance but pres-
ents at birth or within the first few weeks of
life. In nearly every case of neonatal lupus,
the mother is found to have autoantibodies
of the Ro/La family. Children with neonatal LE
are at high risk for developing heart block and
should be followed closely. The rash of peri-
oral dermatitis is not annular and would have
a negative KOH result. However, like tinea fa-
ciei, perioral dermatitis is worsened by using
topical corticosteroids.
Although erythematous annular plaques
are characteristic of granuloma annulare
and neonatal lupus erythematosus, the KOH When dermatophyte fungal infection oc-
curs on the face, it is called tinea faciei. Most
commonly, the fungus will be the anthropo-
C) The KOH test is equivocal. Given the fail-
ure of the mid-potency corticosteroid, a
stronger, Class 1 topical corticosteroid,
should be prescribed, as the patient like-
ly suffers from granuloma annulare.
D) The KOH test is positive. This patient
suffers from perioral dermatitis. Discon-
tinue the use of triamcinolone and begin
oral erythromycin and topical metroni-
dazole cream.
212 • The Journal of the Arkansas Medical Society
philic organism, Trichophyton rubrum. When
history shows the patient had contact with
other species, especially kittens or cats, Mi-
crosporum canis is the zoophilic or-
ganism that should be considered. The
distinguishing characteristics of tinea
faciei are spreading, erythematous,
scaling, annular plaques with a posi-
tive KOH test.
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