Chickenpox (Varicella)

Definition

Chickenpox is a highly contagious viral infection. It produces a widespread itchy rash. Chickenpox can cause serious complications, especially when contracted by adults, newborns, or people with suppressed immune systems.

Causes

Chickenpox is caused by the varicella zoster virus (VZV). It spreads from person to person via:

• Airborne droplets of moisture containing the VZV virus
• Direct contact with fluid from a chickenpox rash

Chickenpox is contagious 1-2 days before the rash erupts. However, it is most contagious just after the rash has broken out and remains contagious until all of the blisters have crusted.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors include:

• Close contact with an infected person (unless you've been vaccinated or have already had chickenpox)
• Age: less than three years old with peak incidence between 5-9 years old
• Immune deficient state (eg, leukemia , organ transplantation)
• Time of year (late winter, early spring)

Symptoms

Adults have more severe symptoms than children. Symptoms usually break out 10-21 days after contact.

Initial symptoms include mild headache, moderate fever, and a general feeling of malaise.

Within 1-2 days after the initial symptoms, a rash develops. The rash consists of small, flat, red spots. The spots become raised and form a round, itchy, fluid-filled blister. The blisters develop in clusters, with new clusters forming over 5-6 days.

The rash usually develops on the skin above the waist, including the scalp. The rash may also appear on the eyelids, in the mouth, upper airway, voice box, or on the genitals. The rash typically crusts over by day six or seven and disappears within three weeks.

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. Diagnosis is usually made on the basis of age and the rash. Blood and laboratory tests to identify the VZV virus are rarely necessary.

Treatment

In most people, chickenpox is mild and will naturally run its course. In these cases, treatment focuses on relieving the symptoms.

Prevention

If you have not had chickenpox and have never been vaccinated, avoid contact with anyone who has the condition.

The varicella vaccine is recommended for virtually all children 12-18 months of age. The second dose is administered between age 4-6 years.

For those who have not been vaccinated, the Centers for Disease Control and Prevention (CDC ) recommend the following schedule:

• Up to age 13 years—2 doses, with an interval of 3 months between the first and second dose (minimum age of 12 months for the first dose)
• 13 years and above—2 doses, with a minimum interval of 4 weeks between the first and second dose *

It is recommended that the following people not be vaccinated:

• Those with a history of severe allergic reaction to vaccines
• Anyone who is immunosuppressed, or receiving immunosuppressive drugs or therapies
• Pregnant women