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strawberry tongue. Pastia lines, bright red, orange, or even hemorrhagic lines, can
occasionally be seen in the axillae or antecubital fossa. The rash generally lasts 3
to 5 days, followed by brownish discoloration and peeling of the skin as small
flakes to entire casts of the digits. A rapid streptococcal test or throat culture
confirms infection.
Epstein–Barr Virus
Between 5% and 15% of patients with Epstein–Barr viral infection, otherwise
known as infectious mononucleosis, will have an erythematous maculopapular
eruption. Infection in young children is usually asymptomatic or so mild that
diagnosis is not sought. Older patients between 15 and 25 years of age are more
likely to present for evaluation. Fifty percent to 100% of patients with infectious
mononucleosis develop a maculopapular rash after receiving concurrent
ampicillin or amoxicillin-containing antibiotics—most commonly for an incorrect
diagnosis of streptococcal pharyngitis.
The illness begins insidiously with headache, malaise, and fever, followed by
sore throat, membranous tonsillitis, and lymphadenopathy. Splenomegaly is
common. The exanthem occurs within 4 to 6 days as a macular or maculopapular
morbilliform eruption most prominent on the trunk and proximal extremities. An
enanthem consisting of discrete petechiae at the junction of the hard and soft
palate occurs in approximately 25% of patients.
Diagnosis is often presumed clinically but may be supported by an absolute
increase in atypical lymphocytes or a positive heterophile antibody (monospot)
test (obtained after the first week of symptoms), or may be confirmed by
serology. The heterophile antibody test is less sensitive in children younger than 4
years of age. The illness is most commonly self-limited, requiring no therapy, but
due to the frequency of associated splenomegaly, affected children should not be
allowed to participate in contact sports until fully recovered and the spleen is no
longer palpable.
Mycoplasma Infections
Infections with Mycoplasma pneumoniae may cause morbilliform rashes in up to
15% of cases. The classic clinical presentation is of a child with malaise, lowgrade fever, and prominent cough. The cough is initially nonproductive but may

become productive, particularly in older children, and may persist for 3 to 4
weeks. Physical examination may reveal bilateral rales.
Diagnosis is suggested by mycoplasma PCR of the sputum or by IgM or IgG
titers of the blood. Erythromycin, clarithromycin, or azithromycin are the


treatment of choice.
Mycoplasma can also induce Stevens–Johnson syndrome (see Chapter 68
Rash: Drug Eruptions ). The rash here is characterized by hemorrhagic lips and
mucosal involvement with fewer bullous lesions on the rest of the skin and is thus
sometimes referred to as Mycoplasma pneumoniae-associated mucositis.
Roseola Infantum
Roseola infantum, also called exanthem subitum or sixth disease , is attributed to
primary infection with human herpes virus (HHV)-6. The illness is characterized
by the onset of a maculopapular rash that appears following a 3- to 4-day febrile
illness. The fever is characteristically high. The rash is widely disseminated,
appearing as discrete, small, pinkish macules that rarely coalesce, beginning on
the trunk and then extending peripherally. The rash may last for hours to days.
The occurrence of the rash within 24 hours of defervescence rather than the
morphologic appearance of the rash itself leads to the correct diagnosis. The rash
can appear very similar to that seen in measles, but the child with roseola appears
well and is no longer febrile. Diagnosis is made clinically and care is supportive.
Disseminated Neisseria Gonorrhoeae
Disseminated Neisseria gonorrhoeae should be considered in sexually active or
potentially abused children, especially if associated with a history of vaginal or
penile discharge. A distinct minority of patients develop disseminated gonorrhea
infection through hematogenous spread. Disseminated gonorrhea may cause a
range of cutaneous lesions, including small erythematous papules, petechiae, or
vesicle-pustules on a hemorrhagic base. These cutaneous lesions usually develop
on the trunk but may occur anywhere on the extremities.

An etiologic diagnosis can be established by demonstration of the organism on
Gram stain of the skin lesion, positive blood culture, or positive culture of oral or
genital sites. Based on resistance patterns, recommended current therapy is
ceftriaxone 50 mg/kg/day (maximum 1 g/day) until clinical improvement is seen,
at which point it can be changed to an oral antibiotic, such as cefixime,
ciprofloxacin, ofloxacin, or levofloxacin, for a total of a 7-day course. Quinolones
should not be used for infections in men who have intercourse with men or in
those with a history of recent foreign travel or partners’ travel, or infections
acquired in other areas with increased resistance. Concomitant sexually
transmitted diseases should be sought and treated.
Secondary Syphilis


One needs a high level of suspicion when viewing rashes in sexually active (or
potentially abused) children to make the diagnosis of secondary syphilis, caused
by the spirochete Treponema pallidum. Manifestations of secondary syphilis
usually occur 6 to 8 weeks after the appearance of the primary lesion, which may
have gone unnoticed. The exanthem extends rapidly and is usually pronounced.
The rash of secondary syphilis is characterized by a generalized cutaneous
eruption, usually composed of brownish, dull-red macules or papules that range
in size from a few millimeters to 1 cm in diameter ( Fig. 88.20 ). They are
generally discrete and symmetrically distributed, particularly over the trunk,
where they follow the lines of cleavage in a pattern similar to pityriasis rosea.
Papular lesions on the palms and soles, as well as the presence of systemic
symptoms, such as general malaise, fever, headaches, sore throat, rhinorrhea,
lacrimation, and generalized lymphadenopathy, help differentiate secondary
syphilis.
Acquired syphilis is sexually contracted from direct contact with ulcerative
lesions of the skin or mucous membranes of an infected individual. Diagnosis
may be presumed after a positive nontreponemal test, such as the VDRL slide

test, rapid plasma reagin (RPR) test, or the automated reagin test. Diagnosis
should be confirmed by a treponemal test, such as the fluorescent treponemal
antibody absorption test, the microhemagglutination test for T. pallidum , or the T.
pallidum immobilization test. Definitive diagnosis may also be made by
identifying spirochetes by microscopic dark-field examination or direct
fluorescent antibody tests of lesion exudate or tissue. Penicillin is the treatment of
choice unless contraindicated, in which case tetracycline, doxycycline,
ceftriaxone, or erythromycin may be substituted. Length of therapy should be
based on duration and stage of infection. Concomitant sexually transmitted
diseases should be sought and treated empirically. HIV testing is recommended
for patients with secondary syphilis.


FIGURE 88.20 Secondary syphilis.

Nonspecific Viral Exanthems
Many times, a specific diagnosis cannot be made, given the large number of
viruses that can be associated with macular or morbilliform eruptions. In
particular, enteroviruses and adenoviruses can cause a macular or morbilliform
eruption. There is little to distinguish the rash caused by one of these viruses from
that of another, based on the location and morphology, with the exception of those
viral infections previously discussed. One usually arrives at the diagnosis of