Varicella & Herpes Zoster

Key Features

Essentials of Diagnosis

• Varicella rash: pruritic, centrifugal, papular, changing to vesicular ("dewdrops on a rose petal"), pustular, and finally crusting

• Zoster rash: tingling, pain, eruption of vesicles in a dermatomal distribution, evolving to pustules and then crusting

General Considerations

• Chickenpox is spread by inhalation of infective droplets or by contact with skin lesions

Demographics

• Disease manifestations include

  • Chickenpox (varicella), which occurs typically in children

  • Shingles (zoster), which occurs more commonly in elderly or immunocompromised persons

Clinical Findings

Symptoms and Signs

Varicella (chickenpox)

• Fever and malaise mild in children, marked in adults

• Vesicular eruptions often first involve oropharynx

• Rash involves face, scalp, and trunk and then moves out to the extremities

• Lesions erupt over 1–5 days so all stages of eruption present simultaneously

• Vesicles and pustules are superficial, elliptical, with slightly serrated borders

• Multinucleated giant cells on Tzanck smear of materials from vesicle bases

Herpes zoster (shingles)

• Pain is often severe and precedes the lesions

• Lesions follow any nerve route distribution (thoracic and lumbar most common)

• Vesicular skin lesions resemble varicella

• Lesions on tip of nose, inner corner of eye, and root and side of nose (Hutchinson sign) indicate potential ophthalmic involvement

• Facial palsy, vertigo, tinnitus, deafness, or external ear lesions suggest geniculate ganglion involvement

• Associations between recent attacks of zoster and the development of multiple sclerosis and Guillain Barré syndrome are recognized

Differential Diagnosis

Varicella (chickenpox)

• Herpes simplex (cold or fever sore; genital herpes)

• Herpes zoster (shingles)

• Contact dermatitis

• Scabies

• Atopic dermatitis (eczema) (acute)

• Miliaria (heat rash)

• Photodermatitis

• Smallpox

• Rickettsialpox

• Hand, foot, and mouth disease

Herpes zoster (shingles)

• Contact dermatitis (eg, poison oak or ivy)

• Herpes simplex

• Varicella (chickenpox)

• Erysipelas

• Prodromal pain mimics angina, peptic ulcer, appendicitis, biliary or renal colic

Diagnosis

Laboratory Tests

• Leukopenia often present in varicella

• Zoster symptoms and signs often highly characteristic, not requiring further diagnostic testing

• When diagnosis remains in doubt, direct fluorescent antibody (DFA) testing, viral culture, and polymerase chain reaction (PCR) testing can be helpful

Diagnostic Findings

• Most patients with a history of exposure and clinical symptoms and signs of varicella do not need further diagnostic testing

Treatment

• VariZIG reduces the severity of varicella in high-risk children or adults (eg, those with impaired immunity, pregnant women, and infants exposed peripartum) if given within 4 days of exposure

Medications

• Uncomplicated infection in otherwise healthy children and adolescents does not require antiviral therapy

• Varicella

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