eMedicine Specialties > Pediatrics: General Medicine > Infectious Disease

Varicella: Follow-up

Author: Parang N Mehta, MD, Consulting Staff, Department of Pediatrics, Mehta Hospital, Surat, India
Coauthor(s): Archana Chatterjee, MD, PhD, Professor of Pediatrics, Medical Microbiology and Immunology, and Pharmacy, Division of Pediatric Infectious Diseases, Chief of Division of Pediatric Infectious Diseases, Creighton University School of Medicine; Hospital Epidemiologist and Medical Director of Infection Control, Children's Hospital
Contributor Information and Disclosures

Updated: Jul 31, 2009

Follow-up

Further Inpatient Care

• Indications for admission to ICU of patients with varicella include the following:
  • Altered consciousness
  • Seizures
  • Difficulty walking 
  • Respiratory distress
  • Cyanosis
  • Low oxygen saturation
• Hospitalize and treat all newborns whose mothers developed varicella less than 5 days before or within 2 days after delivery.

Deterrence/Prevention

The American Academy of Pediatrics (AAP) recommends excluding affected children from school until the sixth day of rash.² This may not prevent spread of varicella because the child is infective before rash appears.

• Vaccination
  • Varicella vaccine consists of live attenuated Oka strain varicella virus. The vaccine is safe and highly immunogenic. It was approved for use in the United States in 1995 and has greatly reduced the incidence and mortality due to varicella.
  • The vaccine has been found to have protective efficacy of 71-100% against varicella. However, protection against moderate and severe varicella is much higher (95-100%).
  • The varicella vaccine is effective after age 1 year. A single dose provides protection to approximately 85% of recipients. Vaccine-conferred immunity to varicella wanes over time, making more vaccine recipients susceptible to the disease. The Advisory Committee on Immunization Practices (ACIP) and the AAP now recommend 2 doses of this vaccine for all children.² After the first dose at age 12-15 months, the second dose should be administered at age 4-6 years. All persons who have received one dose of the vaccine at any time in the past should be offered a second dose.
  • Breakthrough disease involves varicella that occurs after 42 days of immunization. When it occurs, it is usually mild disease but can spread to other susceptible people. Breakthrough disease is more common if the vaccine was given before age 14 months, within 28 days after the measles-mumps-rubella (MMR) vaccine, and if the child was on oral steroid therapy.
  • Research study protocols allow varicella vaccine administration to patients with leukemia while they are in remission.
  • Postexposure prophylaxis, if provided within 72 hours of contact, can prevent or attenuate disease in the exposed individual.
• Varicella-zoster immune globulin
  • VZIG is used as postexposure prophylaxis in high-risk individuals. Administration as soon as possible after exposure is best, but VZIG can prevent or attenuate varicella if administered within 96 hours of contact.
  • The dose is 125 U/10 kg body weight; 125 U is the minimum dose. Maximum dose is 625 IU.
  • VZIG is intramuscularly administered and is never intravenously (IV) administered. The expected duration of protection is approximately 3 weeks. Patients on replacement IV immunoglobulin (IVIG) do not need VZIG if their most recent IVIG infusion was within 3 weeks.
  • VZIG reduces complications and the mortality rate of varicella, not its incidence. Postexposure prophylaxis using varicella vaccine is preferred for immunologically normal patients. VZIG is indicated for the following persons with significant exposure:
    • Newborns of mothers who acquired varicella 5 days before to 2 days after delivery
    • Children with leukemia or lymphoma who have not been vaccinated and have not had varicella previously
    • Persons with HIV, acquired immunodeficiency syndrome (AIDS), or other immunodeficiency disorders
    • Persons receiving drugs that suppress immune function (eg, systemic steroids)
    • Pregnant women
    • Immunocompromised individuals who have no reliable history of chickenpox

Complications

• Secondary bacterial infections
  • Varicella may predispose patients to bacterial infections. Skin lesion infections are common and occur in 5-10% of children. Skin lesions provide a portal of entry for virulent organisms; rapidly spreading cellulitis, septicemia, and other serious infections may occur.
  • The most common infectious organisms are group A streptococci and Staphylococcus aureus. Varicella places the patient at high risk for acquiring invasive group A streptococcal disease. In addition to toxic shock syndrome, group A streptococci may cause necrotizing fasciitis, bacteremia, osteomyelitis, pyomyositis, gangrene, subgaleal abscess, arthritis, and meningitis in patients with varicella.
  • Staphylococcal species also cause severe infections in children with varicella. Staphylococcal infections in these patients reportedly cause cellulitis, impetiginous pox infections, staphylococcal scalded skin syndrome, toxic shock syndrome, pericarditis, and osteomyelitis.
  • Signs and symptoms of secondary bacterial infection can be indistinguishable from uncomplicated varicella during the first 3-4 days.
  • A high level of suspicion is necessary for early recognition and timely appropriate treatment of secondary infections.
  • Suspect secondary infection if systemic manifestations do not improve in 3-4 days, the fever returns or worsens, or the child's condition deteriorates after initial improvement.
  • Suspicion of secondary bacterial infection should prompt early institution of empirical antibiotic therapy until the results of culture studies become available.
  • Neutrophilic leukocytosis and neutrophilia occur in only a few cases involving serious bacterial infections.
  • Investigations cannot be relied on to diagnose or exclude bacterial infection.
• CNS complications
  • Acute postinfectious cerebellar ataxia is the most common CNS complication, with an incidence of 1 case per 4000 patients with varicella.
    • Ataxia has sudden onset that usually occurs 2-3 weeks after the onset of varicella. The condition may persist for 2 months.
    • Manifestations may range from mild unsteadiness to complete inability to stand and walk, with accompanying incoordination and dysarthria. Manifestations are maximal at onset; a waxing and waning course suggests another diagnosis.
    • The sensorium is clear, even when the ataxia is profound.
    • The prognosis for patients with ataxia is good, but a few children may have residual ataxia, incoordination, or dysarthria.
  • Encephalitis occurs in 1.7 patients per 100,000 cases of varicella among otherwise healthy children aged 1-14 years.
    • The disease manifests during acute varicella a few days after rash onset. Lethargy, drowsiness, and confusion are the usual presenting symptoms.
    • Some children may have seizures, and encephalitis can rapidly progress to deep coma.
    • This serious complication of varicella has a 5-20% mortality rate.
  • Reye syndrome was associated with varicella when aspirin use was common. Identification of this association now has made acetaminophen the preferred drug, and Reye syndrome has become rare.
  • Other neurological complications include aseptic meningitis, Guillain-Barré syndrome, and polyradiculitis.
• Pneumonia
  • Pneumonia primarily occurs in older children and adults and can have a fatal outcome.
  • Respiratory symptoms usually appear 3-4 days after the rash.
• Herpes zoster
  • A delayed complication of varicella, herpes zoster infection, occurs months to years after the primary infection in about 15% of patients.
  • The complication is caused by virus that persists in the sensory ganglions.
  • Herpes zoster consists of a unilateral vesicular rash, limited to 1-3 dermatomes. The rash is often painful in older children and adults. Among the health benefits of routine varicella immunization in childhood may be a lifelong decreased risk for reactivation of the virus as shingles.
• Otitis media: About 5% of children with varicella develop otitis media, caused by the usual pathogens.
• Thrombocytopenia
• Hepatitis: Hepatitis is a self-limited accompaniment of varicella.
  • Severe hepatitis with clinical manifestations is infrequent in otherwise healthy children with varicella.
  • Significant elevations of alanine aminotransferase (ALT) occur in 20-50% of children and adolescents, but elevations return to normal within one month in almost all cases.
  • Liver involvement is independent of the severity of skin and systemic manifestations.
• Glomerulonephritis³
• Hemorrhagic varicella

Prognosis

• Otherwise healthy children with varicella have excellent prognoses.
• Children with immunocompromised states are at risk for severe disease and death (eg, the mortality rate among children with leukemia is 7%).
• Neonatal varicella mortality rates can reach 30%.
• An episode of varicella confers immunity. Second episodes are exceedingly rare.

Patient Education

• Bathe the child regularly to reduce itching and prevent secondary infection.
• Scratching can lead to secondary infection and scarring.
  • Keep the fingernails short.
  • Wearing mittens or socks on the hands at night can help prevent scratching.
• Do not use medications that contain aspirin.
• Advise parents to take children to the hospital if the following symptoms occur:
  • Unusual redness, swelling, or pain over an area of the rash
  • Refusal to drink fluids 
  • Signs of dehydration, such as scanty and yellow-colored urine, increasing drowsiness, dry mouth and lips, excessive thirst, or lethargy
  • Confusion, irritability, drowsiness, or difficulty waking
  • Inability to walk or unusual weakness
  • Complaints of severe headache, stiff neck, and/or back pain
  • Frequent vomiting
  • Difficulty breathing, chest pain, wheezing, fast breathing, or severe cough
  • Fever persisting more than 4 days or fever returns after defervescence
  • A more sickly appearance than when last seen by the doctor
• For excellent patient education resources, visit eMedicine's Bacterial and Viral Infections Center. Also, see eMedicine's patient education article Chickenpox.

Miscellaneous

Medicolegal Pitfalls

• Early recognition of secondary bacterial infection and appropriate follow-up are major issues. Failure to recognize occult infection may result in serious illness and even death.
• Isolate patients with varicella because the disease is highly contagious and airborne spread can occur. Isolation is especially important if the hospital also admits patients who are immunocompromised because their exposure to the disease can be serious and even fatal.

Special Concerns

• Pregnancy is a particularly susceptible time. Varicella can cause various adverse outcomes for mother and infant, depending on the stage of pregnancy.
• Immunocompromised children often have severe and complicated varicella, and their mortality rate is higher than that in immunocompetent children. Consider the following categories of patients immunocompromised:
  • Children with any malignancy
  • Children on cancer chemotherapy
  • Children undergoing high-dose corticosteroid therapy
  • Children with congenital cellular immunodeficiencies
  • Children on immunosuppressive therapy
  • Children with HIV infection
• Children with eczema or dermatitis may have severe skin manifestations during varicella.

• Search for CME/CE on This Topic »

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