Chickenpox

January 2017


Definition


Chickenpox is a mild childhood disease, highly contagious, occurring most often in children between the ages of 1 and 14 with a peak between the ages of 5 and 9. It is caused by direct contact with the varicella virus, or VZV. This infection results in lifelong immunity against chickenpox, but the virus hides in the nerve ganglia and can remain dormant for years. When it reactivates, it causes shingles. Incubation of the virus lasts 14 days and the subject is contagious even before the rash appears and until the lesions become crusty. Chickenpox is mostly benign, but when it occurs in immunocompromised individuals, it can have serious repercussions. This is also the case in adult chickenpox where the latter can be complicated by pneumonia. Similarly, varicella in a woman in early pregnancy can cause serious damage to the fetus, and when infection occurs close to birth, neonatal chickenpox can be contracted by the newborn and may lead to its death.

Symptoms


The symptoms of chickenpox are:
  • Fever, that is usually moderate;
  • a rash where lesions typically evolve: a small flat that quickly takes the form of a small rounded lesion giving the impression of containing a clear liquid. After a few days, the bladder is pierced and dried to give a crusty lesion that disappears in about a week;
  • The rash usually starts at the head, especially on the scalp, neck and behind the ears, before spreading to the trunk and face;
  • Another feature is that the disease evolves in short bursts, which is characterized by the coexistence of lesions at different stages of evolution;
  • The lesions may sometimes be itchy.

Diagnosis


The diagnosis of chickenpox is relatively easily made in the presence of the typical clinical signs.

Treatment


The treatment of chicken pox is topical and no antiviral drug is required. A mild cleansing soap is recommended twice daily and an antiseptic solution can sometimes be used as well. To prevent spreading, scratching should be avoided by cutting one's nails short, and possibly by using prescription antihistamines. Paracetamol should be used for fever but aspirin or nonsteroidal anti-inflammatory drugs are strictly forbidden. The child must be isolated. In case of infection of lesions, an antibiotic treatment is sometimes used.

Prevention


Chickenpox being a highly contagious disease, the affected child should be kept home from school until the crusty stage where the pox are no longer contagious. As for immunocompromised individuals, they must also avoid contact with the virus. A vaccine exists, but is used in very specific indications.

Related

Published by Jeff. Latest update on July 23, 2013 at 12:36 PM by Jeff.
This document, titled "Chickenpox," is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM Health (health.ccm.net).