Chicken Pox

Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus (VZV). It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and become itchy, raw pockmarks, which mostly heal without scarring.

Chicken pox is spread easily through coughs or sneezes of ill individuals or through direct contact with secretions from the rash. Following primary infection there is usually lifelong protective immunity from further episodes of chickenpox.

Chickenpox is rarely fatal, although it is generally more severe in adult males than in adult females or children. Pregnant women and those with a suppressed immune system are at highest risk of serious complications. Chicken pox is now believed to be the cause of one third of stroke cases in children. The most common late complication of chicken pox is shingles, caused by reactivation of the varicella zoster virus decades after the initial episode of chickenpox.

Chickenpox is a highly infectious disease that spreads from person to person by direct contact or by air from an infected person’s coughing or sneezing. Touching the fluid blister can also spread the disease. A person with chickenpox is infectious from one to five days before the rash appears. The contagious period continues until all blisters have formed scabs, which may take 5 to 10 days. After the spots have scabbed over, the sufferer is still highly contagious, from 10 to 21 days, meaning they can still spread the virus through close contact, breathing, and even sleeping in someone’s bed. It takes from 10 to 21 days after contact with an infected person for someone to develop chickenpox. Chickenpox (varicella) is often heralded by a prodrome of anorexia, myalgia, nausea, fever, headache, sore throat, pain in both ears, complaints of pressure in head or swollen face, and malaise in adolescents and adults, while in children the first symptom is usually the development of a papular rash, followed by development of malaise, fever (a body temperature of 38 °C (100 °F), but may be as high as 42 °C (108 °F) in rare cases), and anorexia. Rarely cough, rhinitis, abdominal pain, and gastrointestinal distress has been reported in patients with varicella. Typically, the disease is more severe in adults.

The diagnosis of varicella is primarily clinical, with typical early “prodromal” symptoms, and then the characteristic rash. Confirmation through either examination of the fluid within the vesicles of the rash, or by testing blood for evidence of an acute immunologic response.

Vesicular fluid can be examined with a Tsanck smear, or better with examination for direct fluorescent antibody. The fluid can also be “cultured”, whereby attempts are made to grow the virus from a fluid sample. Blood tests can be used to identify a response to acute infection (IgM) or previous infection and subsequent immunity (IgG).

Prenatal diagnosis of fetal varicella infection can be performed using ultrasound, though a delay of 5 weeks following primary maternal infection is advised. A PCR (DNA) test of the mother’s amniotic fluid can also be performed, though the risk of spontaneous abortion due to the amniocentesis procedure is higher than the risk of the baby developing foetal varicella syndrome.

12-24