.Chickenpox (varicella) - complications.Specific Complications of Chickenpox (Varicella).

Chickenpox (varicella) rarely causes complications, but it is not always harmless. It can cause hospitalization and, in rare cases, death. Fortunately, since the introduction of the vaccine in 1995, hospitalizations have declined by nearly 90%, and there have been few fatal cases of chickenpox.
Adults have the greatest risk for dying from chickenpox, with infants having the next highest risk. Males (both boys and men) have a higher risk for a severe case of chickenpox than females. Children who catch chickenpox from family members are likely to have a more severe case than if they caught it outside the home. The older the child, the higher the risk for a more severe case. But even in such circumstances, chickenpox is rarely serious in children. Other factors put individuals at specifically higher risk for complications of chickenpox.
Recurrence of Chickenpox and Reactivation as Shingles
Recurrence of Chickenpox. Recurrence of chickenpox is possible, but uncommon. One episode of chickenpox usually means lifelong immunity against a second attack. However, people who have had mild infections may be at greater risk for a breakthrough infection later on.
Reactivation of the Virus as Shingles (Herpes Zoster). The major long-term complication of varicella is the later reactivation of the herpes zoster virus and the development of shingles. Shingles occurs in about 20% of people who have had chickenpox.

Specific Complications of Chickenpox (Varicella)
Aside from itching, the complications described below are very rare.

Itching. Itching, the most common complication of the varicella infection, can be very distressing, particularly for small children. Certain home remedies are available that can alleviate the discomfort. [See: "Treatment for Chickenpox" section below.]
Secondary Infection and Scarring. Small scars may remain after the scabs have fallen off, but they usually clear up within a few months. In some cases, a secondary infection may develop at sites which the patient has scratched. The infection is usually caused by the bacteria Staphylococcus aureus or Streptococcus pyogenes. Permanent scarring may occur as a result. Children with chickenpox are at much higher risk for this complication than adults are, possibly because they are more likely to scratch.
Ear Infections. Some children are at higher risk for ear infections from chickenpox. Hearing loss is a very rare result of this complication.
A middle ear infection is also known as otitis media. It is one of the most common of childhood infections. With this illness, the middle ear becomes red, swollen, and inflamed because of bacteria trapped in the eustachian tube.
Bacterial Superinfection. Bacterial superinfection of the skin caused by group A streptococcus is the most common serious complication of chickenpox (but it is still rare). The infection is usually mild, but if it spreads in deep muscle, fat, or in the blood, it can be life threatening. Infection can cause serious conditions, such as necrotizing fasciitis (the so-called flesh-eating bacteria) and toxic shock syndrome (TSS).

Symptoms include:

A persistent or recurrent high fever
Redness, pain, and swelling in the skin and the tissue beneath
Pneumonia. Pneumonia is suspected if coughing and abnormally rapid breathing develop in patients who have chickenpox. Adults and adolescents with chickenpox are at some risk for serious pneumonia. Pregnant women, smokers, and those with serious medical conditions are at higher risk for pneumonia if they have chickenpox. Oxygen and intravenous acyclovir are key treatments for this condition. Pneumonia that is caused by varicella can result in lung scarring, which may impair oxygen exchange over the following weeks, or even months.

Bacterial Superinfection. Bacterial superinfection of the skin caused by group A streptococcus is the most common serious complication of chickenpox (but it is still rare). The infection is usually mild, but if it spreads in deep muscle, fat, or in the blood, it can be life threatening. Infection can cause serious conditions, such as necrotizing fasciitis (the so-called flesh-eating bacteria) and toxic shock syndrome (TSS).