Comments
INITIAL SYMPTOMS:
Chickenpox: mild fever and a maculopapular rash developing into superficial vesicles located mainly on the trunk; Vesicles can be seen in various stages of development; Lesions almost never found on palms and soles; [PPID, p. 745]
FINDINGS:
The stages of the rash are maculopapular (few hours), vesicular and pustular (3-4 days), and crusted (about 5 days after onset of the rash). [The vesicle looks like a teardrop on a red base or a "dew drop on a rose petal."]. Unlike smallpox vesicles, they collapse when punctured. Complications of chickenpox include pneumonia, encephalitis, and bleeding. Herpes zoster occurs in patients previously infected with the chickenpox virus. The reactivation of the dormant varicella virus occurs in the dorsal root ganglion. Some patients develop permanent pain (postherpetic neuralgia) in the affected dermatome. [CCDM, p. 669-70] The lesions appear as successive crops over 2 -4 days so that all stages of development (papules, vesicles, pustules, and scabs) are visible. Lesions are usually about 5 mm in diameter, but may be as large as 13 mm. Varicella pneumonitis occurs in about 1 in 400 adult cases. [PPID, p. 1733-4] In varicella-zoster myelitis from shingles, patients may have weakness in the myotomes corresponding with the affected dermatomes. [PPID, p. 1155] Vesicles in the mouth can cause painful swallowing. Complications include cellulitis, transient arthritis, hepatitis, and transient encephalopathy (occurs in <1/1000 cases and resolves in <2 weeks), and Reye's syndrome (coma). [Merck Manual, p. 1415] Herpes zoster may cause conjunctivitis, keratitis, uveitis, and, rarely, cranial nerve palsies. Blindness is a complication of herpes zoster ophthalmicus. Symptoms of encephalitis include seizures, headache, and vomiting. [Guerrant, p. 994, 360] WBC count may be low, normal, or slightly elevated. [5MCC-2015] In primary or systemic VZV infections, elevation of transaminases is typical. Thrombocytopenia occurs in severe disease. [Wallach, p. 606] Skin lesions may be hemorrhagic in patients with immunosuppression, e.g., leukemia. [ABX Guide] See "Keratitis."
PREVENTION:
"Exposed susceptibles eligible for immunization should receive vaccine as soon as possible after exposure to prevent disease and transmission with potential occurrence of an outbreak." Varicella-zoster immune globulin is available in several countries for immunodeficient patients and pregnant women. [CCDM, p. 674] VariZIG is an investigational alternative to VZIG; VZIG is no longer available. [ABX Guide] "Only HCP with evidence of immunity to varicella should care for patients who have confirmed or suspected varicella or HZ. . . . Unvaccinated HCP who have no other evidence of immunity who are exposed to VZV (varicella, disseminated HZ, and uncovered lesions of a localized HZ) are potentially infective from days 8-21 after exposure and should be furloughed during this period. They should receive postexposure vaccination as soon as possible. Vaccination within 3-5 days of exposure to rash might modify the disease if infection occurred." (See recommendations for HCP at risk for severe disease for whom varicella vaccination is contraindicated.) A vaccine to prevent HZ [herpes zoster] is available and recommended for all persons aged > or = 60 years without contraindications to vaccination." [ACIP, 2011]
For updated text and symptoms of infectious diseases, see iddx.com.
Diagnostic
Typical skin eruption; If not sure, can confirm with Tzanck smear, culture, immunofluorescence stains, or PCR; [ABX Guide] Commercial kits to detect varicella-zoster by IgM are not recommended. {CDC Travel]