Chickenpox: Symptoms and Treatment Options

Chickenpox is a common childhood disease. Highly contagious, it is characterised by a fever and small, red, itchy blisters on the face and body.

Anyone can get chickenpox. However, while it is more common in children, its effects are often more severe in adults than in children.
While chickenpox is common and harmless to most people, it may have an adverse impact on those whose immune systems are impaired such as newborn infants, those undergoing chemotherapy for cancer, people with AIDS, as well as those taking steroids like cortisone or prednisone. People with impaired immune systems may experience serious complications or even death.
Chickenpox can also give rise to more severe problems in pregnant women, causing stillbirths or birth defects, and can spread to their babies during childbirth. It can, however, be prevented through vaccination.

Causes and Risk Factors

Chickenpox is a highly infectious viral illness that is caused by a herpes virus called varicella-zoster.
It is also highly contagious. It spreads from person to person through direct contact or by droplets from an infected person when he coughs or sneezes. It can also spread indirectly through articles freshly soiled by droplets or fluid from the blisters of an infected person. The scabs themselves are not considered infectious.
One can get chickenpox within 10–21 days after contact with an infected person. An infected person is usually infectious one or two days before the rash appears until about a week later when the spots have stopped forming and have dried.
Once you have had chickenpox, you are immune to the disease and are very unlikely to catch it again. The virus particles remain dormant in your nervous system. However, it can at a later stage cause shingles.

Chickenpox Symptoms

An infected person usually has a fever, together with red spots on the body and face. The spots appear over a few days and progress from being red spots to blisters which eventually burst, dry up and form crusts before healing. These spots are usually itchy and may leave scars when scratched.


Possible complications of a chickenpox infection include:
  • Skin infection such as sores becoming more red, swollen, or tender.
  • Dehydration due to frequent vomiting or refusal to drink. The person will pass urine less often, feel drowsy, have a dry mouth and lips, and be very thirsty.
  • Brain damage from encephalitis, which may present with a severe headache, stiff neck and back, confusion, irritability, or excessive drowsiness.
  • Pneumonia characterised by coughing, wheezing, breathing difficulty, and chest pain.
  • Arthritis characterised by joint pain, stiffness, and swelling.

Chickenpox Treatment

In healthy children, chickenpox is usually a mild disease. Treatment is directed at reducing the itch and discomfort. Children with chickenpox should not receive aspirin because of the possibility of causing a complication called Reye’s syndrome, which is a very serious illness that can cause liver and brain damage.
There are also antiviral medications that can be used to treat chickenpox. These are usually most effective when taken within the first 24 hours of developing the illness. They reduce the severity and duration of the disease, as well as reduce the likelihood of complications. Most children do not need them. Most adults would benefit from them if taken early enough, especially those who have impaired immunity as they are more susceptible to severe chickenpox.


  • Avoid scratching as it can cause scarring. Scratching may also affect the healing process and increase the risk of bacterial infection. To minimise damage due to scratching, one may wear gloves especially at night and trim the fingernails.
  • Take cool baths to help relieve itching especially for children. Dabbing the spots with calamine lotion may also help relieve the itching.
Seek immediate medical attention if the following conditions occur:
  • The rash spreads to one or both eyes.
  • The rash gets very red, warm, or tender indicating a possible secondary bacterial skin infection.
  • The rash is accompanied by dizziness, disorientation, rapid heartbeat, shortness of breath, tremors, loss of muscle coordination, worsening cough, vomiting, stiff neck, or high fever.


Chickenpox can be prevented through vaccination. The vaccine is safe and effective in protecting those who have never had chickenpox.
Two doses of varicella vaccinations are recommended at 12 and 15 months. If the child is age 12 months or older, they are eligible for varicella vaccination and subsidies. Older Singaporean children, adolescents and adults who are previously unvaccinated are also recommended and eligible for varicella vaccination subsidies at CHAS GP clinics and polyclinics if they have not been previously vaccinated against varicella
Adults, such as non-immune healthcare workers, and those who live or work in conditions where transmission can easily occur, such as foreign workers and college students, are advised to have the chickenpox vaccination. In the latter case, outbreaks can result very quickly among non-immune adults who are more susceptible to severe chickenpox. Non-pregnant women of child-bearing age who are not immune should also be vaccinated.
The chickenpox vaccine is expected to provide lifelong immunity.
Click here for more information on vaccine-preventable diseases, subsidies available, and frequently asked questions.

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