Chickenpox: definition transmission and treatment

Definition of Chickenpox

Chickenpox or varicella is really a highly infectious illness caused by a virus. It's usually a mild illness that used to be typical in schoolchildren before 1995, when a vaccine against it was introduced in the United States. It does occasionally produce complications, nevertheless, particularly in adults who become infected with it and those with a weakened immune system.

Description

Chickenpox is a highly contagious disease that spreads rapidly because people can transmit the virus for several days before they feel sick. In most individuals, the virus enters the body via the nose and throat when the individual breathes in air that contains the virus or droplets from an infected person's sneezing or coughing. Once inside the body, the virus multiplies in the lymph nodes of the upper respiratory tract for two to four days after the infection begins. It then enters the bloodstream and travels to the spleen and liver, where it continues to multiply for an additional week or ten days. At this point the virus invades the skin and begins to produce the skin rash that is a classic sign of chickenpox.

The rash begins as red macules, or flat spots, on the surface of the face and body. Most children have about 250-500 of these spots but may have as many as 1,500. The spots develop in a series of crops or batches that go through characteristic stages. The flat macules grow over a period of ten to twelve hours into papules, or raised reddish pimples.

The papules in turn turn out to be vesicles, which are fluid-filled blisters that at first look like a dewdrop on a rose petal. The vesicles eventually burst and turn into open sores before crusting over. One of the distinctive marks of chickenpox is that the child will have rashes in a number of various stages at the exact same time. The child is contagious until the last of the vesicles has burst and has totally crusted over. The most typical complication of chickenpox is really a secondary bacterial infection, which can happen if the child scratches the vesicles and bacteria invade the raw skin underneath.

An infection can produce inflammation of the skin and a high fever. Impetigo, an additional skin illness characterized by sores covered with honey-colored crusts and eventual scarring of the skin, may also result. In some instances bacteria can invade the bloodstream, leading to eventual bacterial pneumonia or infection of the middle ear. Because of the risk of bacterial infection, it is essential to keep a child with chickenpox from scratching the skin rash. An additional possible complication is the transmission of the chickenpox virus from a mother who develops the disease to the unborn baby. A baby whose mother develops chickenpox within five days before delivery or two days after delivery can become very sick from the virus if the mother isn't treated.

Demographics

Before 1995, chickenpox was considered one of the classic diseases of childhood, along with measles and mumps; about 4 million instances were reported each year in the United States. About 11,000 people were hospitalized annually with chickenpox in North America, and between fifty and 100 of these individuals died. Since 1995, the number of instances in the United States has declined about 90 percent, and there are only about ten deaths from chickenpox reported each year most of them in people who had been not immunized.

In the United States and Canada, about 90 percent of instances of chickenpox occur in children younger than fourteen years, with the remaining 10 percent affecting older teenagers and adults. There are about 90 million cases of chickenpox reported around the world each year. Whereas chickenpox is most typical in kids between the ages of one and fourteen years in countries with temperate climates, it affects as many adults as children in countries with tropical climates. In North America chickenpox is most typical in late winter and spring. As far as is recognized, chickenpox strikes all races and both sexes equally.

Chickenpox: Causes and Symptoms

Chickenpox is caused by a virus recognized as the varicella-zoster virus or VZV. This virus is really a member of a family of viruses called human herpesviruses; it is related to the viruses that cause oral and genital herpes infections. The chickenpox virus could be spread by breathing air containing droplets from an infected person's sneezing or coughing, or by direct contact with an infected person or their clothing. The earliest symptoms of chickenpox occur during its prodrome, a brief period of time that precedes the main symptoms of a illness. During the prodrome, which is more likely to happen in teenagers and adults than in younger kids, the individual might complain of a headache, nausea, general tiredness, and loss of appetite.

In many children, the first sign of chickenpox is the appearance of the characteristic rash, accompanied by tiredness along with a low-grade fever of 100-102°F (37.8-38.9°C). In a few kids the fever may rise as high as 106°F (41.1°C). The characteristic rash of chickenpox has already been described. It takes about a week for each crop of macules to move through the complete cycle of forming papules, vesicles, and crusted sores. Successive crops of macules usually appear for five to seven days, which indicates that the child should be considered contagious for a minimum of a week after the appearance of the last group of macules. Fever rarely lasts longer than four days. The child might not feel like eating if there are vesicles forming inside the mouth or throat; the sick child ought to, however, be encouraged to drink lots of fluids to prevent dehydration.

Diagnosis of Chickenpox

The physician usually diagnoses chickenpox on the basis of its external signs and symptoms; in most instances it's not necessary to take a sample of blood or fluid from the vesicles for a laboratory test. In many instances the physician is helped in diagnosing the disease by asking whether the child has been exposed to anyone with chickenpox in the last ten to twenty-one days. It's feasible to identify the chickenpox virus in samples of fluid taken from the patient's vesicles, but these tests are costly, some are slow and may not be dependable, and others require special laboratory equipment that isn't readily accessible to most doctors.

Chickenpox Treatment

Chickenpox is considered a self-limiting illness; that is, people usually recover from it with out requiring special treatments. Kids with chickenpox should be kept house from school or daycare to steer clear of infecting others; however, they don't need bed rest. They ought to stay house until all the chickenpox blisters have totally crusted over. The child's fingernails should be trimmed short to prevent the blisters from becoming infected if the child scratches them.

Very young kids might need to have their hands covered with mittens to reduce the risk of infection from scratching. For relief from the itching caused by the skin rash, children can be bathed in cool water with baking soda added every 3 to five hours. Other treatments for the itching include Aveeno oatmeal baths, application of calamine lotion, or oral antihistamines. Kids can be given acetaminophen or ibuprofen to bring down the fever and to relieve the headache and sore muscles that sometimes accompany chickenpox. They should never be given aspirin, nevertheless, simply because of the risk of Reye syndrome.

Reye syndrome is really a two-stage illness of young children that follows a viral infection with fever like chickenpox or flu and is thought to be linked to taking aspirin for the fever. People with weakened immune systems, like those with HIV infection or leukemia, should be treated with acyclovir (Zovirax), which is really a drug that is usually given to treat oral or genital herpes. Acyclovir can reduce the time it takes for a person with a weak immune system to recover from chickenpox. In addition, adults who develop chickenpox should be given acyclovir simply because they are at greater risk than kids of developing complications, such as pneumonia.

Prognosis

Most children with chickenpox recover completely; however, some develop skin infections as a result of scratching the blisters, and about 5 percent may develop earaches or pneumonia if the bacteria infecting the skin sores have gotten into the bloodstream. An additional typical complication is shingles, an inflammation of the skin caused by a flare-up of the chickenpox virus that has remained in the nervous system after the child has recovered from chickenpox itself. Shingles, or herpes zoster, usually occurs decades after the chickenpox episode. Kids with leukemia have a 7 percent mortality rate from chickenpox. In otherwise healthy children, the mortality rate is about two per 100,000 instances.

Prevention

Most individuals who recover from chickenpox are immune for their the rest of their lives; it is very unusual for a person who has had chickenpox in childhood to have it again as an adult. Chickenpox can be prevented by immunization with the vaccine introduced in 1995. The vaccine, known as Varivax, is recognized to be effective for a minimum of eight years; however, its longer-term effectiveness needs further study. As of 2008 the American Academy of Pediatrics (AAP) recommended two immunizations with Varivax, the first dose given to infants between twelve and fifteen months of age and also the second given to children between the ages of four and six years.

Some states have made vaccination for chickenpox mandatory alongside vaccinations for polio, mumps, and measles. It's important for a woman who is pregnant and has by no means had chickenpox to check with her doctor about her immune status. Pregnant women or babies younger than one year aren't given Varivax. They and people with weak immune systems can be protected against chickenpox by receiving varicella-zoster immune globulin, or VZIG, a preparation made from human immunoglobulin. A pregnant woman who develops chickenpox within five days before her due date or two days after childbirth should be given VZIG and acyclovir to protect the baby's health.