Varicella in Child
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Synopsis
Varicella, or chickenpox, is an acute, highly contagious exanthem caused by primary infection with varicella-zoster virus (VZV). The virus is believed to be spread by respiratory droplets and skin vesicles from individuals with varicella or herpes zoster (a dermatomal rash caused by reactivated endogenous VZV) to the respiratory tract of susceptible children. In immunologically normal children, the illness typically begins after an incubation period of 2-3 weeks, lasts 3-7 days, and resolves without complication. One varicella episode usually confers lifelong immunity, although reinfections have been documented.
In rare cases, varicella is associated with prolonged courses and severe complications, including bacterial superinfection, pneumonia, encephalitis, bleeding disorders, and hepatitis. Adolescents and immunocompromised children (eg, malignancy, congenital defects in cell-mediated immunity, organ transplant recipients, children receiving long-term immunosuppressive therapy, or human immunodeficiency virus [HIV]-infected children) are at elevated risk for complications.
Varicella was a common viral disease of children until childhood vaccination in the United States became routine during the 1990s. The disease remains common in nondeveloped countries and is seen more frequently in older children and adults.
In vaccinated individuals, "breakthrough varicella" can occur. Illness is usually mild (low fever or no fever, fewer lesions [less than 50], less pruritic, shorter duration, absence of vesicles), although some patients present similar to unvaccinated individuals.
Note: In 2022 and 2023, pediatric invasive group A streptococcal (iGAS) infections and noninvasive group A streptococcal infection cases have been associated with respiratory infections due to parainfluenza, rhinovirus, enterovirus, influenza, and human metapneumovirus, among other viruses. Concurrent or preceding viral infections, including varicella (chickenpox), may increase risk for iGAS infection. Severe outcomes of iGAS infections include necrotizing fasciitis, streptococcal toxic shock syndrome, and death.
Related topic: varicella pneumonia
Codes
ICD10CM:B01.9 – Varicella without complication
SNOMEDCT:
38907003 – Varicella
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Differential Diagnosis & Pitfalls
- Eczema herpeticum – Prior history of eczema; lesions favor the extremities, and vesicles are often grouped or confluent.
- Drug eruption (Stevens-Johnson syndrome, bullous drug eruption) – Associated with drug exposure.
- Miliaria crystallina – No viral symptoms; lesions do not rapidly progress to pustules and crusts.
- Disseminated herpes simplex virus (HSV) – Concentrated in sites typically infected by HSV (oral mucosa, perioral area, and genitalia) and occurs in patients with depressed immunity or underlying dermatoses.
- Hand-foot-and-mouth disease – Favors hands, feet, and oral mucosa.
- Impetigo – Gradually progressive, superficial erosions, very fragile bullae, and favors exposed sites.
- Insect bite reactions – Larger papules and vesicles, and lesions do not rapidly progress to pustules and crusts; favor exposed sites.
- Molluscum contagiosum – No viral symptoms; lesions do not rapidly progress to pustules and crusts.
- Pityriasis lichenoides et varioliformis acuta (PLEVA) – Recurrent crops of papulovesicles that crust and resolve with residual hypopigmentation, less pruritus, and no mucous membrane involvement.
- Gianotti-Crosti syndrome – Lesions are monomorphic edematous papules (in contrast to various stages of lesions seen with PLEVA).
- Monkeypox
- Variola (smallpox) – All lesions at the same stage; favors extremities. Note: this disease has been eradicated; therefore, it would only be diagnosed in the event of a bioterrorist act.
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Last Updated:04/06/2023
Patient Information for Varicella in Child
Overview
Chickenpox (varicella) is an infectious disease caused by the varicella-zoster virus that goes away on its own. Infection spreads among humans through fluids from the airways, such as from coughing and sneezing, with non-infected household members at high risk of becoming infected as well. The development (incubation) period is 14-16 days, and the first sign of disease is a rash. People are considered contagious for 2-5 days before the onset of skin lesions and for 6 days after the last series of rashes have appeared.The most common complication is infection of lesions with bacteria. Rare complications include lung infection (pneumonia) or brain infection (encephalitis). Children who have weak immune systems, eczema, or recent sunburns have more severe symptoms. Because the virus remains resting (latent) in the parts of nerves that are near the spinal cord (nerve roots) for life, about 1 in 10 adults will get shingles (zoster) when the virus reappears, usually under conditions of stress to the body.
After having chickenpox, a person is usually immune for life, although reinfection is possible.
Who’s At Risk
Chickenpox occurs most commonly in children under 10. Those under 1 year of age (whose mothers have had chickenpox before) are not usually infected, as they still have some immunity from their mother's antibodies, which were transferred to them before birth.The chickenpox vaccine has been part of routine childhood vaccinations (at age 12-18 months) since 1995, but many children have still not been vaccinated. About 85% of children who have been vaccinated avoid infection, but even if they do show symptoms, they are generally mild. Most infections occur from March to May.
Signs & Symptoms
Most children act sick with fever and vague symptoms (loss of appetite, headache, belly ache) for 1-2 days before they start to break out with a rash. These symptoms last for 2-4 days after the rash appears.An early pink-to-red, flat, small spot rapidly becomes bumpy and then blisters with a surrounding halo of redness. The spots usually appear first on the trunk or scalp. Linings of body cavities, such as the mouth or nose (mucous membranes), palms, and soles, can have a few lesions. The average child develops a few hundred blisters, most of which heal without leaving scars. A child who has had the chickenpox vaccine will have far fewer lesions.
The blister is usually described as looking like a dewdrop on a rose petal. The blister area (vesicle) is thin-walled and easily broken. Blisters become cloudy and then crust over, with healing completed within 1-3 weeks. Lesions often occur in 3 or more successive series (crops). Lesions in different stages of development may occur at the same time.
Self-Care Guidelines
Since the illness resolves on its own after 1-3 weeks, it is most important to keep the child comfortable and to discourage scratching, which can cause infection and scars.For itching:
- Oatmeal baths in lukewarm water
- Oral antihistamines (diphenhydramine, chlorpheniramine)
- Clip the child's fingernails
- Apply calamine lotion
- DO NOT USE lotions containing antihistamines or lidocaine, as they are no more effective than the previous measures and might cause allergic reactions later on.
- Use acetaminophen (eg, Tylenol).
- DO NOT USE aspirin in children aged 18 years or younger, as the use of aspirin in children with chickenpox has been associated with Reye syndrome, a severe disease.
- The American Academy of Pediatrics recommends AVOIDING treatment with ibuprofen (eg, Advil) if possible because it has been associated with life-threatening bacterial skin infections.
When to Seek Medical Care
Most infections do not require treatment.If there are adults or teens in the household who have never had chickenpox or people with eczema, asthma, or a weakened immune system, have them contact their doctor, as they may require antiviral medication. This usually needs to be done early (during the first day of the rash).
Call your child's doctor if:
- He or she has eczema, asthma, or a weakened immune system.
- The fever lasts more than 4 days or exceeds 102 degrees Fahrenheit.
- Any rash areas look red, swollen, and leak pus.
- He or she has a severe cough, vomiting, headache, drowsiness, confusion, stiff neck, trouble looking at bright lights, or difficulty walking or breathing.
Treatments
Antiviral medication may be given if the child is seen early (during the first day of the rash) for children at higher risk for more severe chickenpox infection (those with asthma, eczema, recent sunburn, children taking aspirin or corticosteroids on a regular basis, and those with weak immune systems).References
Bolognia, Jean L., ed. Dermatology, pp.1241-1243. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.2070, 2080-2081, 2434-2437. New York: McGraw-Hill, 2003.
Varicella in Child