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Chicken Pox Information

Chicken Pox Information

Full Body Checkup

Close-up of Typical early vesicular rash

Full Body Checkup

Vesicles have started to crust over

Department of Public Health Department of Public Health And Infection Prevention and Control, Community and Disability Services Infection Prevention and Control, Community and Disability Services HSE South (Cork and Kerry) HSE South (Cork and Kerry) February 2012

What is chickenpox?

Chickenpox is an acute infectious disease caused by the varicella zoster virus. Most children have chickenpox at some stage. It cannot be treated with antibiotics. Treatment is usually for the symptoms

What are the signs and symptoms of chickenpox?
  • Fever, aches and feeling tired and irritable often start a day or so before a rash appears
  • Rash – Spots appear in crops.
  • At first the rash appears like small red pimples that typically develop into blisters full of fluid and are usually itchy. Several crops may develop in waves over three to five days after the rash begins. Therefore different clusters of spots may be at different stages of blistering or crusting.
  • The blisters dry up and “crust over”. They gradually fade but may take up to two weeks to go completely.
  • Some children feel quite unwell for a few days while others may only appear mildly ill. Most are much better within a week.

How does chickenpox spread?

Chickenpox is very infectious. The virus spreads in the air from person to person. For example, if you have not already had chickenpox, there is a good chance of catching it if:

  • You are in the same room as someone with chickenpox for one hour of more
  • You have any face-to-face contact with someone with chickenpox, such as a conversation.

Chickenpox is most infectious one to two days before the rash appears until the last blister has dried up. The rash may start 10-21 days after being exposed to someone with chickenpox although it is usually between day 14-16.

What is the treatment for chickenpox?

There is no specific treatment for chickenpox. It is a viral illness that will therefore not respond to antibiotics. Treatment is aimed at easing the symptoms whilst the immune system deals with the virus. The following simple measures may help to alleviate symptoms

  • Give lots to drink. This helps to avoid dehydration and control the fever.
  • Dress appropriately to avoid getting too hot or too cold.
  • Wear smooth, loose-fitting cotton fabrics which should prevent the skin from becoming sore and irritated.


The rash can be intensely itchy but it is important not to scratch to avoid future scarring.

    • Calamine lotion on the spots may ease itching.
    • Antihistamine medicine for children over one year old may help with sleep if itch is a problem. Give a dose at bedtime. You can buy these at pharmacies or get them on prescription.
  • Scratching increases the risk of secondary bacterial infection so
    • Keep fingernails trimmed short and
    • Keep the rash clean and dry.
  • Avoid the use of antibiotic creams and adhesive dressings, as they may cause irritation and delay rash healing.
  • Seek medical advice if there is an increase in temperature (after an initial improvement), as this may indicate bacterial infection.

What are the possible complications of chickenpox?

Complications of chickenpox are rare in healthy children. The most common one is when the blister rash becomes infected with bacteria.

If large, sore, red areas develop around the rash or your child becomes unwell (after an initial improvement), see your family doctor in case a secondary bacterial infection has developed.

Very rarely, other serious complications develop and it is best to be vigilant. See a doctor if your child develops any worrying symptoms that you are unsure of such as:

  • Breathing problems
  • Weakness, drowsiness or convulsions
  • Pains or headaches that become worse despite paracetamol or ibuprofen
  • Being unable to take fluids as he/she has a severe rash in his/her mouth
  • A severe rash, or a rash which bruises or bleeds into the skin (haemorrhagic rash)
  • Becoming generally more and more unwell.

Special considerations

The following people should talk to their doctor if they think they have been exposed to or develop chickenpox as they may have a higher risk of developing complications and need extra treatment such as antiviral medication.

  • Anyone who is taking long term steroids and anyone with a poor immune system for example, people with leukaemia, on chemotherapy or after an organ transplant.
  • Pregnant women
  • Newborns
  • People with skin conditions such as eczema for advice on creams that can be used for the rash.

Preventing the spread of chickenpox
  • If your child has chickenpox, inform their school, nursery or day care as there may be other children who need to inform their GP that they have been exposed. Keep them at home until the last blister has burst and crusted over. This is usually five to six days after the rash first appears.
  • If you have chickenpox, do not go to work or college if the rash is weeping and only return once the rash has dried and crusted over – at least 5 days after the rash has appeared. Again, inform your workplace that you have chickenpox as there may be others you work with who may need to inform their GP that they have been exposed.
  • You can return to work or school once all scabs are crusted over – some remaining scabs are not a reason for continued exclusion as the scabs are not infective.
  • If you or your child has chickenpox it is a good idea to avoidcontact with:
    • pregnant women who cannot recall having had chickenpox,
    • babies younger than 1 month of age or
    • anyone who has a weakened immune system such as those on chemotherapy or radiotherapy, receiving long term steroids or have had organ transplants
  • If you or your child have recently been exposed to chickenpox, you may not be able to visit friends, family or relatives in hospital. Telephone the ward first to check.
  • People with chickenpox should not travel by air until six days after the last spots appeared.