How to Diagnose Puzzling Pediatric Skin Problems 46 Clinical Rounds

46
Clinical Rounds
SKIN & ALLERGY NEWS • October 2005
How to Diagnose Puzzling Pediatric Skin Problems
BY HEIDI SPLETE
Senior Writer
Pilomatricoma
A 15-month-old girl presented with a
bump on her cheek—a firm, bluish, cystic papule that moved back and forth under pressure. When one end of the lesion
was palpated, the other end would pop up,
a phenomenon also known as a “teetertotter sign.”
Annular Urticaria
A 3-year-old girl presented with red,
swollen, annular plaques on her skin, and
had swollen hands and feet. She had been
otherwise healthy and was taking no medications. The condition arose suddenly; the
parents noticed the rings and swelling one
morning when picking up the child from
her bed. On closer inspection, the rings
were red and blanchable, with clear white
Wheezing in Infants Worsens Near Stop-and-Go Traffic
B Y M I C H E L E G.
S U L L I VA N
Mid-Atlantic Bureau
I
nfants who live near roads with
lots of stop-and-go bus and
truck traffic are significantly
more likely to develop wheezing
than those who live near steady
traffic or those who aren’t exposed to much traffic, Patrick
Ryan and his associates reported.
The association may be related
to increased amounts of diesel
exhaust particles (DEP) shed
when the vehicles accelerate
from a stop, said Mr. Ryan, of the
University of Cincinnati, and his
colleagues. Other studies have
shown that acceleration from
stop increases this particulate
matter.
“Sampling for fine particulate
matter and black carbon inside a
bus and a car traveling ahead of
the bus showed that the average
DEP levels were approximately
20 mcg/m3 and 5 mcg /m3, but
during stop-and-go traffic the levels increased to more than 30
mcg /m3 and 20 mcg/m3, respectively,” they said.
The researchers examined
wheezing without cold over 1
year in 622 infants (median age
7.5 months).
The infants were part of the
Cincinnati Childhood Allergy
and Air Pollution Study; all had at
least one atopic parent, the researchers said ( J. All. Clin. Immunol. 2005;116:279-84).
Living within 100 meters
of stop-and-go traffic was
associated with a 2.5-fold
increased risk of
wheezing and was the
most important risk factor.
Most (374) of the infants were
unexposed to traffic; 176 lived
near moving bus and truck traffic, and 99 lived near stop-and-go
traffic. Infants exposed to stopand-go traffic were more likely to
be black, have out-of-home care,
and have a father with asthma,
and they were less likely to have
been breast-fed. The researchers
adjusted for these variables in the
analysis.
Of the 622 infants, 8% (50) reported wheezing without a cold.
The prevalence of wheezing in
the unexposed infants was 5.8%.
The prevalence was 7.4% in infants exposed to moving traffic,
and 17.2% in infants exposed to
stop-and-go traffic.
The prevalence of wheezing
was three times higher (19%) in
infants who lived less than 50
meters from moving traffic compared with the unexposed group,
the investigators said.
The prevalence of wheezing
in those who lived 200-300 meters from moving traffic was
12%—more than double that of
infants who were unexposed.
Living within 100 meters of
stop-and-go traffic was associated
with a 2.5-fold increased risk of
wheezing and was the most important risk factor for wheezing.
However, the authors noted,
“Because wheezing in the first
year of life is generally a poor
predictor of later development of
childhood asthma, results must
be interpreted cautiously.”
■
P HILADELPHIA
OF
centers. Some were
imperfect circles.
The diagnosis is
annular urticaria.
“These types of
cases are frequently
referred for suspected erythema
multiforme,” Dr.
Yan noted. “Lesions of annular urticaria are evanescent; the lesions
fade and move, and
the lesions can
form imperfect circles with clear centers,” he explained.
The lesions may
disappear within 24
hours, only to show
up elsewhere, he
said. By contrast,
erythema multi- Annular urticaria, which is often mistaken for erythema
forme appears as multiforme, can be distinguished by its evanescence.
fixed target, or
“bull’s-eye,” lesions with dusky centers erythema multiforme requires a detailed
and is associated with mucous membrane history to determine underlying causes,
removal or treatment of those causes, and
ulcers.
The two conditions are treated quite dif- consideration of steroid therapy if indiferently, Dr. Yan emphasized. Annular ur- cated. Dr. Yan often refers to annular urticaria responds to combinations of anti- ticaria as “urticaria multiforme” because
histamines or occasionally steroids; these cases are so regularly mistaken. ■
C HILDREN ' S H OSPITAL
Although these lesions may resemble
dermoid cysts or epidermal inclusion
cysts, the diagnosis in this case was pilomatricoma, distinguished by its bluish color and the presence of the teeter-totter
sign.
The lesions most often occur on the
head or neck, although other areas occasionally are affected. Pilomatricomas generally are solitary, benign, frequently calcified, and arise from hair follicles. In
some cases, the lesions resolve spontaneously, but more often, they persist and
grow, and surgical intervention is recommended.
Pilomatricomas may rupture, which can
cause inflammation and scarring. Although pilomatricomas generally are isolated findings, they may be associated
with systemic disorders such as Gardner’s
syndrome, myotonic dystrophy, and sarcoidosis.
Pilomatricomas may be associated with systemic disorders
such as Gardner’s syndrome or sarcoidosis.
COURTESY
The Hair Collar Sign
A boy is born with an area of localized, circular alopecia covered by a glossy membrane. The area is surrounded by a collection of dark, terminal hairs. Palpation
reveals that a lump is present.
Occasionally mistaken for fetal scalp
monitor trauma, neonatal herpes simplex
infection, or a nevus sebaceus of Jadassohn, this characteristic pattern—a collar
of coarse hair surrounding an area of
membranous aplasia cutis congenita—can
be a marker for cranial dysraphism, a developmental defect of the skull potentially associated with structural neurologic
defects. The scalp defect may represent
only the tip of the iceberg, Dr. Yan noted,
since underlying bony defects or ectopic
brain tissue may be present.
In such cases, magnetic resonance imaging is essential to rule out underlying abnormalities, including atretic encephalocele or heterotopic brain tissue.
A collar of hair around membranous aplasia cutis congenita
can indicate the presence of cranial dysraphism.
P HOTOS
O R L A N D O — Pediatric skin conditions
often pose diagnostic challenges because
many cutaneous disorders have similar
clinical features.
Annular lesions of granuloma annulare
may be mistaken for tinea corporis; follicular papules of keratosis pilaris may be
confused with follicular eczema; and nail
psoriasis may be misdiagnosed as onychomycosis.
At a meeting sponsored by the American Academy of Pediatrics, Albert C. Yan,
M.D., director of pediatric dermatology at
the Children’s Hospital of Philadelphia,
provided some helpful diagnostic tips for
distinguishing some of these potentially
puzzling dermatologic problems.