Your Child's Arm Plaster

Your Child's Arm Plaster

Plasters (also called casts or plaster casts) and splints allow your child's broken bone time to rest and heal.


Key points about your child's arm plaster

  • children with fractures have plasters and splints to prevent the bones from moving and to allow the bone time to rest and heal
  • it is very important that your child returns for their follow-up appointments

What is the purpose of a plaster or splint?

Children with fractures have plasters (also called casts or plaster casts) and splints to prevent the bones from moving. This allows the fracture (broken bone) time to rest and heal.

See the KidsHealth page on fractures for more information

What should my child do while waiting for their plaster to dry?

An arm plaster cast takes 24 to 48 hours to dry completely.

In the first hour or two, while your child is waiting for their plaster to harden, it's a good idea to rest their arm on something soft, such as a pillow or in a sling. Hard surfaces may damage your child's plaster.

How can I help care for my child while they have their arm plaster on?

The following DOs and DON'Ts are some guidelines to help you care for your child while they have their plaster on.

Photo of young girl with an plaster cast on her arm

Some DOs

  • keep the arm raised, especially for the first 24 to 48 hours, to prevent swelling
  • rest the plaster on something soft until dry - use a pillow when sitting or lying down
  • support the arm in a sling - ask your doctor about how long to do this
  • make sure your child moves their fingers often 
  • encourage your child to gently move the joint above the plaster (their elbow or shoulder) to avoid stiffness
  • check the colour of your child's fingers - they should be pink, and if you squeeze the fingernails and then let go, they should quickly return to pink
  • watch for swelling - compare it to the other hand - are they about the same size?
  • keep the cast clean and dry
  • check around the plaster for any smells - plasters do have a slight smell but have it checked if you are worried
  • ring the emergency department or contact your doctor if you are concerned

Some DON'Ts

  • don't use hairdryers or other drying equipment to dry the plaster - they may burn your child or crack the plaster - let the plaster dry naturally
  • don't press on the plaster for 24 to 48 hours until dry - pressing on it will dent it
  • don't write on the plaster until it is dry
  • don't get it wet
  • don't poke anything, such as knitting needles or other sharp objects, down the plaster - they may damage your child's skin and lead to infection
  • don't put lotions, creams or powder inside the plaster or around the edges
  • don't cut or remove the plaster - ring the hospital if it is uncomfortable
  • don't knock or bump the plaster
  • don't keep the sling on longer than instructed

How can my child bathe with their arm plaster?

  • wrap a towel around the plaster
  • place the arm in a plastic bag large enough to cover it completely
  • secure the end with tape (such as sellotape)
  • there are also some special coverings for plasters - ask your doctor about these
  • don't put the arm in the bath - rest it on the edge of the bath
  • don't aim the showerhead at the affected arm

When should I seek help for my child's arm plaster?

After going home, you should take your child back to the emergency department or contact your doctor urgently if your child:

  • complains of pain that is getting worse even with pain relief and raising the broken arm
  • has a hand that is going cold, pale or blue or becoming more swollen
  • complains of fuzziness, numbness, pins and needles or tingling in the fractured arm or in their fingers
  • cannot move their fingers

If your child's plaster becomes cracked, broken, soft or loose, or it is rubbing, contact your doctor. 

Will my child need follow-up appointments for their arm plaster?

It is very important that your child goes to all their follow-up appointments.

Your child will usually need a fracture clinic appointment 5 to 14 days after leaving hospital. At this appointment, your child may have another x-ray to make sure the bone is healing and is in place. Your child will usually need to go to several more appointments at a fracture clinic to make sure the break is healing.

Ask your nurse or doctor for instructions for your child's follow-up before you leave hospital.

When will my child's arm plaster be removed?

Photo of young girl having her arm plaster cast removed

When your child's injury has healed, their plaster will be removed with specially designed plaster shears or saw that will cut through the plaster but cannot cut the skin.

Plaster removal is a fast and painless process.

When can my child return to physical activity after their arm plaster comes off?

Your doctor will tell you how much physical activity your child can do while their injury heals. After the plaster comes off, your doctor will guide you about when your child should go back to various activities. 

This page last reviewed 14 June 2021.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it