Pediatric emergency medicine trisk 345

Those patients with herpes simplex infection should be advised that
reactivation of the virus may occur in between 15% and 50% within 6 to 12
months. Prompt antiviral treatment for any reactivation should be advised
through their primary care clinician or dermatologist to avoid a recurrence of
more widespread viral secondary infection.

Papular-Purpuric Gloves-and-Socks Eruption
Papular-purpuric gloves-and-socks eruption (PPGS) presents as an often
painful petechial eruption concentrated on the palms and soles, but often
extending proximally to involve the skin of the wrists, forearms, ankles, and
lower legs in a so-called “gloves-and-socks” distribution ( Fig. 70.16 ). The
condition is triggered most commonly by infection with parvovirus B19,
although other organisms have been linked to this condition, including
cytomegalovirus, HHV 6,7, coxsackie B6, Epstein–Barr virus (EBV),
hepatitis B virus, measles virus, Arcanobacterium hemolyticum , and
Mycoplasma pneumoniae.

FIGURE 70.16 Papular-purpuric gloves-and-socks eruption caused by parvovirus B19.
Note the multiple petechial papules on the ankles and feet which were also present on
palms and forearms.


PPGS tends to affect young adults, typically during the spring and
summer. Affected patients often have low-grade fevers along with painful,
symmetrically distributed, petechial papules. There is often a sharp cutoff
where the lesions stop. The oral mucosa may be affected. PPGS
spontaneously resolves after approximately 1 to 3 weeks. However, it is
important to evaluate patients thoroughly in order to distinguish PPGS from
more serious bleeding disorders, septicemias, or rickettsial disorders such as
Rocky Mountain spotted fever. Rare associations have included coincident
mononeuritis multiplex and red cell aplasia concurrent with PPGS attributed

to the underlying parvovirus B19 infection.

Unilateral Laterothoracic Exanthem
Unilateral laterothoracic exanthem (ULE), also known as asymmetric
periflexural exanthem, is a self-limited phenomenon attributed to a virus. It
is thought to be viral because a viral prodrome may be associated. ULE
occurs in community clusters, and patients generally do not experience
recurrences. The condition is characterized by collections of blanchable pink
macules, papules, and plaques originating in flexural creases such as the
axillary, inguinal, or popliteal areas, which then extend unilaterally along the
thorax and extremity ( Fig. 70.17 ). Often, the eruption generalizes and
becomes bilateral within several days. Symptoms may include mild itching.
While many viral exanthems resolve spontaneously within 1 to 2 weeks,
ULE is longer lasting, and often takes approximately 1 month before it
resolves. Recognition of the condition can allow the clinician to provide
reassurance and an anticipated time course to the family regarding the
natural history of the condition.
It is interesting to note that infection with molluscum contagiosum can
trigger a ULE-like eruption. This reactive ULE-like phenomenon, however,
is of often shorter duration and is typically responsive to topical steroid
treatment, in contrast to ULE.


FIGURE 70.17 Unilateral laterothoracic exanthem characterized by a viral exanthem
involving the right flank.


FIGURE 70.18 Gianotti–Crosti syndrome. Note the characteristic sparing of the
distribution of this reactive process triggered by a viral syndrome.