Chickenpox (varicella) Diagnosis, Pathophysiology and Treatment - PART-I

 

Chickenpox is an infection caused by the varicella-zoster virus. Most children have chickenpox at some stage. Most commonly, children get chickenpox before the age of 10 years. The immune system makes proteins called antibodies during the infection. These fight the virus and then provide lifelong protection against it (immunity). Therefore, it is uncommon to have more than one bout of chickenpox in your lifetime.

Cause:

The varicella-zoster virus may be spread through the air when an infected person coughs or sneezes or by direct contact with the blisters (lesions) of someone infected with chickenpox or shingles.

The risk of getting chickenpox is higher for people who have had contact with an infected person, are under 12 years old, have a weakened immune system, or who work or spend time in a school or daycare facility.

Once someone is infected, the virus usually incubates for 14 to 16 days before a rash appears, although incubation can last from 10 days to 21 days. There are no symptoms during incubation and a person doesn't become contagious until 1 to 2 days before the rash appears. The person remains contagious until all the blisters have dried and scabs have formed. 

To prevent the spread of the virus to others, people who have or are suspected to have chickenpox should avoid public places, such as school, until all blisters have scabbed over. 

Chickenpox Blisters: 

Symptoms:

The itchy blister rash caused by chickenpox infection appears 10 to 21 days after exposure to the virus and usually lasts about five to 10 days. Other signs and symptoms, which may appear one to two days before the rash, include:

• Fever
• Loss of appetite or feeding problems to child
• Headache
• Tiredness and a general feeling of being unwell (malaise)

 

Once the chickenpox rash appears, it goes through three phases:

• Raised pink or red bumps (papules), which break out over several days
• Small fluid-filled blisters (vesicles), which form in about one day and then break and leak
• Crusts and scabs, which cover the broken blisters and take several more days to heal

New bumps continue to appear for several days, so you may have all three stages of the rash — bumps, blisters and scabbed lesions — at the same time.

You can spread the virus to other people for up to 48 hours before the rash appears, and the virus remains contagious until all broken blisters have crusted over. 

The disease is generally mild in healthy children. In severe cases, the rash can cover the entire body, and lesions may form in the throat, eyes, and mucous membranes of the urethra, anus and vagina.

 Chickenpox Scabbing: 

 

Some children feel quite unwell for a few days. Others appear only mildly ill. Most are much better within a week. The blisters dry up and scab. They gradually fade but may take up to two weeks to go completely. 

Most of the time, children with chickenpox recover fully and have no complications. Uncommonly, one or more of the following complications can occur.

 

• The spots do not usually scar unless they are badly scratched.
• Some spots become infected with germs (bacteria) in some cases. This is the most common complication in children. If this occurs, the surrounding skin becomes red and sore. Antibiotics in the form of creams or medicine may then be needed.
• Inflammation of the lung (pneumonia) and inflammation of the brain (encephalitis) are rare complications.
• Vary rarely, other serious complications develop. For example: 

ü  Reye's syndrome. (A very rare condition with brain and liver problems).

ü  Inflammation of the heart muscle (myocarditis).

ü  Kidney inflammation (glomerulonephritis).

ü  Appendicitis.

ü  Ataxia (problems co-ordinating movements).

ü  Inflammation of the pancreas (pancreatitis).

ü  Henoch-Schönlein purpura (a condition that can affect the kidneys).

ü  Inflammation of the testes (orchitis).

ü  Inflammation of the joints (arthritis).

ü  Inflammation of various parts of the eye.

Therefore, although serious complications are rare, it is best to be watchful. Consult with Medical Practitioner if your child develops any worrying symptoms that you are unsure about such as:

 

• Breathing problems.
• Weakness such as a child becoming wobbly on his/her feet.
• Drowsiness.
• Fits (convulsions).
• Pains or headaches which become worse despite paracetamol.
• Being unable to take fluids, due to a severe rash in the mouth.
• A severe rash, or a rash which bruises or bleeds into the skin (haemorrhagic rash).
• Becoming generally more and more unwell.

 Shingles

Shingles is caused by the same virus that causes chickenpox and is a very delayed complication of chickenpox. Anyone who has had chickenpox in the past may develop shingles. Shingles is an infection of a nerve and the area of skin supplied by the nerve. It causes a rash and pain in a local band-like area along the affected nerve. About 1 in 5 people have shingles at some time in their lives. It can occur at any age, but it is most common in people over the age of 50.

 

The reason why shingles may occur is because the virus does not completely go after you have chickenpox. Some virus particles remain inactive in the nerve roots next to your spinal cord. They do no harm there and cause no symptoms. For reasons that are not clear, the virus may begin to multiply again (reactivate). This is often years later. The reactivated virus travels along the nerve to the skin to cause shingles.

Note: you can catch chickenpox from being exposed to a person with shingles if you have not had chickenpox yourself. However, you cannot catch shingles from a person with chickenpox, or catch shingles from a person with shingles.