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nonspecific viral exanthem in a child in whom other diagnoses have been
excluded and who may have signs of associated illness or systemic features such
as fever. If specific diagnosis is required, it can be determined by viral isolation
and/or a rise in diagnostic titer.

Generalized Eruptions Without Fever
Many generalized eruptions are not associated with fever. Many are fairly easily
recognizable, such as psoriasis, contact dermatitis, pityriasis rosea.
Guttate Psoriasis and Pityriasis Rosea
Please see Chapter 70 Rash: Papulosquamous Eruptions and Viral Exanthems for
full discussion of papulosquamous skin rashes.
Rubella
Rubella is rarely seen in the postvaccine era in the United States. In a classic case
of rubella, the rash, similar to measles, begins on the head and spreads caudally.
The progression occurs over 2 to 3 days, and typically, the rash is entirely gone
by the fourth day. The rash always remains macular and never becomes confluent,
which is an important distinguishing characteristic from measles. One-third of all
rubella virus infections is clinically silent (i.e., they have no exanthem). The rash
of rubella may show extensive variation in location, progression, and duration, at
times disappearing within 12 hours or being localized to one part of an extremity
without any progression.
Unlike measles, in which systemic toxicity and fever are the rule, fever is
uncommon. Associated symptoms and complaints in rubella include joint pain
and adenopathy (most commonly suboccipital, postauricular, and cervical).
Arthralgia that occurs with a viral exanthem is highly characteristic for rubella.
Diagnosis is based on clinical presentation, and treatment is supportive.

Vesicles/Bullae
Enterovirus Infections
Enterovirus infection can not only cause morbilliform exanthems but can also
cause vesicles and blisters. The classic exanthem of coxsackievirus A16 infection,

also appropriately called hand–foot–mouth disease , is common and easily
recognized. Infections may occur in epidemics, most commonly in the late
summer or early fall. Multiple infected members within a household are common.
Coxsackievirus A16 infection begins with a prodrome of low-grade fever,
anorexia, mouth pain, and malaise, followed within 1 to 2 days by an oral


enanthem and then shortly thereafter by red macules and papules. The oral lesions
begin as small red macules, most often located on the palate, uvula, and anterior
tonsillar pillar, which evolve into small vesicles that ulcerate and heal over a 1- to
6-day period. The exanthem develops into small crescent or football-shaped
vesicles on an erythematous base ( Fig. 88.14 ). These vesicles, which may be
pruritic or mildly tender, are usually located on the dorsal and lateral aspects of
fingers, hands, and feet but may develop on the buttocks, arms, legs, and face.
The lesions improve over 2 to 7 days.
The other types of coxsackievirus cause similar or even indistinguishable
exanthems, which may more commonly involve the face, trunk, and proximal
extremities. Often, children with these exanthems will be diagnosed with
nonspecific viral infections. Other symptoms attributed to coxsackie virus
infection include aseptic meningitis and less commonly myopericarditis, pleuritis,
encephalitis, or paralysis. Severe and/or persistent infections may be seen in
immunocompromised hosts.
Diagnosis is usually made clinically, although the virus can be detected by
PCR directly from the vesicles or from the stool. The virus is commonly shed for
weeks from stool. Coxsackievirus infections are usually self-limiting, so no
specific treatment is necessary. IVIG with high antibody titer may be considered
for immunocompromised patients or in life-threatening neonatal infections.
Coxsackie virus also frequently infects eczema prone areas and in this case is
called eczema coxsackium (similar to eczema herpeticum).
Varicella (Chickenpox)

Although varicella is an easily recognizable vesiculobullous eruption, on
occasion, the earliest phase can be confusing. The initial skin manifestations of
varicella virus infection are small, red macules. Some of the lesions remain as
macules, but most progress to papules and then the characteristic umbilicated,
tear-shaped vesicles. The earliest lesions appear on the chest and spread
centrifugally, but there are many exceptions to the pattern of spread. Mucosal
lesions can be seen but are usually not a prominent feature. Occasionally, a child
with mild chickenpox may have only a few scattered macules with only one or
two progressing to the more typical vesicular lesions. Of children receiving
varicella vaccine, 7% to 8% may develop a mild maculopapular or varicelliform
rash within 1 month of vaccination.
Other Bullae/Vesicles


Blisters can be related to bug bites, contact allergy, friction, drug reaction,
vasculitis, primary genetic disease of the skin, and fluid overload. A full
discussion of blisters can be found in Chapter 67 Rash: Vesiculobullous . Chapter
70 Rash: Papulosquamous Eruptions and Viral Exanthems , covers HSV and
Chapter 65 Rash: Atopic/Contact Dermatitis and Photosensitivity , covers eczema
herpeticum.

Localized Eruptions Without Fever
Contact dermatitis, insect bites, papular acrodermatitis, and scabies usually
present in a localized distribution; however, all may appear as a more generalized
eruption in extensive cases.
Contact Dermatitis
Contact dermatitis may be caused either by a primary exposure to an irritant or by
an acquired delayed hypersensitivity response to a sensitizing substance. A sharp
demarcation commonly exists between the involved and uninvolved skin areas.
Affected skin is erythematous with variable numbers and combinations of

macules, papules, vesicles, and/or bullae.
Diagnosis depends on obtaining a thorough history of exposure and the
presence of a characteristic localized pattern of rash. Treatment for both types of
these dermatitides includes eliminating exposure to offending irritants, providing
topical or systemic antipruritic agents, and for more severe cases, providing
topical or systemic steroids. Please see Chapter 65 Rash: Atopic/Contact
Dermatitis and Photosensitivity for additional information.
Insect Bites
Virtually all children experience insect bites. Mosquitoes, fleas, and bedbugs are
the most common offenders. Diagnosis depends on the season, the climate,
exposure to animals, and distribution and appearance of the lesions. Care is aimed
at minimizing discomfort with topical or systemic antihistamines and/or topical
steroids.
Papular Acrodermatitis (Gianotti–Crosti Syndrome)
Papular acrodermatitis is an eruption of unclear cause that has been associated
with hepatitis B, EBV, and other viral infections in young children, including a
similar reaction in the setting of MC. In the pediatric population, 85% are
younger than 3 years. The eruption may follow a low-grade fever or mild upper
respiratory symptoms.


The eruption consists of skin-colored papules that occur anywhere on the body
but often concentrate on the extensor surfaces of the arms, legs, and buttock.
Lesions are particularly prominent over the elbows and knees. The rash usually
lasts 2 to 8 weeks and then disappears. No treatment is needed for the cutaneous
eruption; however, a subset of patients with cutaneous lesions develops
generalized lymphadenopathy and hepatosplenomegaly. These children should be
evaluated for hepatitis and follow-up in 2 weeks is recommended for patients
with only cutaneous involvement to exclude hepatitis.
Scabies

Scabies is discussed in Chapter 70 Rash: Papulosquamous Eruptions and Viral
Exanthems .

Chronic Eruptions Without Fever
Chronic eruptions are defined as those that are usually present for a minimum of
2 weeks.
Atopic Dermatitis
Although the eruption may have a variable appearance (erythema, edema,
papules, vesicles, serous discharge, and crusting), its constant feature is pruritus.
The eruption often has a characteristic distribution, depending on age, and often
occurs in allergic (atopic) individuals or those with a family history of allergies
(e.g., hay fever, asthma, allergic rhinitis, food allergies, eosinophilic
gastroenteritis). Please see full discussion in Chapter 65 Rash: Atopic/Contact
Dermatitis and Photosensitivity .
Tinea
Dermatophyte infections usually last longer than 2 weeks. A full discussion can
be found in Chapter 66 Rash: Bacterial and Fungal Infections/Rash:
Maculopapular . In short, tinea corporis is characterized by one or more sharply
circumscribed scaly patches. The center of the circular patch generally clears as
the leading edge spreads out. The leading edge may be composed of papules,
vesicles, or pustules. The lesions are most commonly confused with nummular
eczema. The diagnosis can be made by scraping the active outer rim of papules
and examining the scales with a potassium hydroxide (KOH) preparation under
the microscope. These lesions do not fluoresce under the Wood light. Treatment
with topical antifungal agents such as clotrimazole, miconazole, econazole,
terbinafine, and butenafine produces clearing in 7 to 10 days. Therapy should be
maintained for at least 2 weeks. If improvement does not occur, treatment with