A 4½-month-old male presents to your office for evaluation of a
couple of “pimples” below his lower lip along with swelling and
erythema of the chin. The pimples first appeared a couple of days earlier, and
the mother squeezed the larger one, producing a small amount of pus. Since
then, the baby has been irritable with some subjective fever and worsening
erythema and swelling involving the chin.
James H. Brien
His past medical history is remarkable only for having been 35
weeks’ gestation, but the pregnancy, labor and delivery were otherwise
normal. Mother denied any history of herpesvirus infections. The baby was in
the neonatal ICU for only 5 days and has done well since. His immunizations are
up-to-date for his age. No one at home has had any cold sores or other skin
infections, and there are no other known sick contacts.
Examination revealed an alert, interactive, healthy-appearing baby,
appropriate for his stated age, with a temperature of 101·F,
respirations of 30 and crying, a pulse of 140 with a capillary refill time of 2
seconds. The only positive findings were the lesion on his lower lip and chin
and a hemangioma on the lower part of the chin, well away from the area of
erythema as shown in Figure 1. As shown, the chin was red and swollen, and
there were some discrete pustular lesions just below the lower lip (Figure 2).
A CBC revealed a WBC count of 27,000, with 60% granulocytes and 19%
lymphocytes and 490,000 platelets.
The baby was admitted to the pediatric ward, where he underwent a
sedated incision and drainage of the lesion (Figures 3–5); a Gram stain
and culture for bacteria and herpesvirus polymerase chain reaction are pending.
What’s Your Diagnosis?
- Erythema toxicum
- Cutaneous herpes simplex
- Staphylococcus aureus infection
- Propionibacterium acnes infection
The Gram stain was positive for gram-positive cocci in clusters, and
methicillin-sensitive Staphylococcus aureus (MSSA) grew from the culture
(answer C). The herpesvirus polymerase chain reaction was negative.
There’s nothing unusual about staphylococcal cellulitis and abscess
occurring on a baby, but the location is a bit unusual, and the appearance of
the pustular lesions looked very much like herpes simplex virus, and I’m
not altogether convinced that the problem did not actually start as a herpes
infection that may have become secondarily infected when the pustules were
squeezed. We may never know, but clearly, there was an abscess involving the
chin that appeared to track to the pustules below the lip, as gentile pressure
on the chin produced copious exudate from the site of the pustules.
Erythema toxicum is a common, benign skin condition of newborns, but a
bit unusual at this age and produce smaller pustules, as shown in Figure 6. The
lesions typically appear between 4 and 14 days of age and are described as
benign papulo-pustular lesions on erythematous bases. They can appear anywhere,
but are more common on the trunk. If the contents of a lesion is stained
(H&E), one is likely to see eosinophils; Gram stain will reveal no
organisms and culture will be negative. They require no therapy.
As noted above, cutaneous herpes can look very much like the lesion in
this case (Figures 7 and 8), and the fact that the polymerase chain reaction
was negative does not rule it out. But then S. aureus can have
angry-looking pustules also; got to go with the culture results.
Lastly, Propionibacterium acnes, the major cause of acne, can
certainly provide the port-of-entry for an opportunistic S. aureus to
produce cellulitis and abscess when these “zits” are picked and
popped, even with relatively mild acne, as with the patients in Figures 9, 10
and 11.
Columnist Comments
Summer is here and children are at increased risk for accidents,
including drowning. This is a good time to encourage your parents to teach
their children to swim and use extra caution with their backyard pools when
young children are around. Also, if your adolescents come in with a
tetanus-prone injury and in need of a booster, take the opportunity to give
them the Tdap (tetanus-diphtheria-acellular pertussis) vaccine, and take
another small step toward protecting babies from exposure to pertussis.
Let’s hope it’s a boring summer.
James H. Brien, DO, is Vice Chair for Education at The
Children’s Hospital at Scott and White and is the Associate Professor of
Pediatrics at Texas A&M University, College of Medicine, Temple, Texas.
email: jhbrien@aol.com.
Disclosure: Dr. Brien reports no relevant financial disclosures.