Frequently Asked Questions About Casts

Frequently Asked Questions About Casts

Kids who need a cast often have plenty of questions. Here are answers to some frequent inquiries about casts.

What are the different kinds of casts?

A cast, which keeps a bone from moving so it can heal, is essentially a big bandage that has two layers — a soft cotton layer that rests against the skin and a hard outer layer that prevents the broken bone from moving.

These days, casts are made of either:

How is a cast put on?

First, several layers of soft cotton are wrapped around the injured area. Next, the plaster or fiberglass outer layer is soaked in water. The doctor wraps the plaster or fiberglass around the soft first layer. The outer layer is wet but will dry to a hard, protective covering. Doctors sometimes make tiny cuts in the sides of a cast to allow room for swelling.

layers of a cast illustration

Can plaster of paris casts get wet?

Absolutely not! A wet cast may not hold the bone in place because the cast could start to dissolve in the water and could irritate the skin underneath it, possibly leading to infection. So your child shouldn't swim and should use a plastic bag or special sleeve (available online or sometimes at pharmacies) to protect the cast from water. And instead of a shower, your child may need to take a sponge bath.

Can synthetic (fiberglass) casts get wet?

Although the fiberglass itself is waterproof, the padding inside a fiberglass cast is not. So it's still important to try to keep a fiberglass cast from getting wet. If this is a problem, talk to the doctor about getting a waterproof liner. Fiberglass casts with waterproof liners let kids continue bathing or even go swimming during the healing process. Although the liner allows for evaporation of water and sweat, it's still fragile. Also, only certain types of breaks can be treated with this type of cast. Your doctor will determine if the fracture may be safely treated with a waterproof cast.

Is it OK to have people sign and draw on my child's cast?

Definitely! That often makes the whole broken bone experience more bearable for kids. Permanent markers usually work best; washable ones can smear. Feel free to encourage siblings, family members, and classmates to sign it, draw pictures on it, or decorate it with stickers. The doctor might even let your child keep the adorned cast as a souvenir.

What if my child has an itch in the cast?

Try blowing some air in the cast with a hair dryer — be sure to use the cool setting, though. And you should never pour baby powder or oils in the cast to try to relieve itching or try to reach the itch with long, pointed object such as a pencil or hanger — these could scratch or irritate your child's skin and can lead to an infection.

What if the cast gets a crack?

This can happen if the cast is hit or crushed, has a weak spot, or if the injured area begins to swell underneath. Call your doctor as soon as you notice a crack. In most cases, a simple repair can be done to the cast without needing to remove it or change it.

What if the cast causes my child's fingers or toes to turn white, purple, or blue, or if the skin around the edges of the cast gets red or raw?

If your child’s fingers or toes are changing color, the cast may be too tight and you should call the doctor right away.

Redness and rawness are typically signs that the cast is wet inside, from sweat or water. Sometimes, kids pick at or remove the padding from the edges of fiberglass casts. They shouldn't do this, though, because the fiberglass edges can rub on the skin and cause irritation. Call your doctor to have the problem fixed right away.

Why aren't some types of broken bones put in casts right away?

Some kinds of fractures are put into a splint at first, then later switched to a cast. If there is concern about swelling, the doctor may do this so a cast doesn’t get too tight.

Do all broken bones need casts?

No. Some fractures, such as a rib or collarbone, are not casted. Even displaced collarbones (in which pieces on either side of the break are out of line) heal well with a sling or special strap called a "figure-of-eight clavicle strap," which the child wears like a vest. Some non-displaced finger and toe fractures (in which the pieces on either side of the break line up) that don't involve the joint or the growing part of a child's bone (called the growth plate) may heal well with a splint or buddy taping (taping the injured digit to the adjacent unaffected finger or toe).

Certain fractures of larger long bones, such as the femur (thighbone), are hard to keep straight in a cast. Although doctors used to put many of these kinds of fractures in traction (a way of gently pulling the bone straight), these days, surgery is often used instead.

Will my child feel pain when the broken bone is in a cast?

Some pain is expected for the first few days, but it's usually not severe. The doctor may recommend acetaminophen or ibuprofen to ease pain.

How are casts taken off?

The doctor will use a small electrical saw to remove the cast. Although it may look and sound scary to your child, the process is actually quick and painless. The saw's blade isn't sharp — it has a dull, round blade that vibrates up and down. The vibration is strong enough to break apart the fiberglass or plaster, but shouldn't hurt your child's skin and may even tickle.

What will the injured area look and feel like when the cast is removed?

Once the cast is off, the injured area will probably look and feel pretty weird to your child: The skin will be pale, dry, or flaky; hair will look darker; and the area (muscles especially) will look smaller or weaker. Don't worry, though — this is all temporary. And depending on the type and location of the fracture, the doctor may also give your child special exercises to do to get the muscles around the broken bone back in working order.

Reviewed by: Larissa Hirsch, MD
Date reviewed: February 2014





Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

© 1995-2014 The Nemours Foundation/KidsHealth. All rights reserved.





Bookmark and Share

Related Resources
OrganizationAmerican Academy of Orthopaedic Surgeons (AAOS) The AAOS provides information for the public on sports safety, and bone, joint, muscle, ligament and tendon injuries or conditions.
OrganizationAmerican Academy of Pediatrics (AAP) The AAP is committed to the health and well-being of infants, adolescents, and young adults. The website offers news articles and tips on health for families.
Related Articles
Babysitting: Dealing With Broken Bones What should you do if a child you're babysitting has a broken bone? Our tip sheet can help you be prepared.
Broken Bones Instruction Sheet Broken bones are not uncommon in children - especially after a fall. A broken bone requires emergency medical care. Find out what to do in this printer-friendly version.
Casts and Splints This article for teens has tips on taking care of a cast so it keeps working as it should.
What to Expect When Your Cast Comes Off You probably can't wait to get back to your normal activities, but it takes a while for a limb that's been in a cast to finish healing. Here's what to expect.
Dealing With Broken Bones A broken bone requires emergency medical care. Find out what to do in this printable instruction sheet.
When Your Child Needs a Cast Casts keep bones in place while they heal. Depending on the severity of the injury, a cast can be worn for a few weeks to a few months.
Bones, Muscles, and Joints Without bones, muscles, and joints, we couldn't stand, walk, run, or even sit. The musculoskeletal system supports our bodies, protects our organs from injury, and enables movement.
Broken Bones Although many kids will have one at some point, a broken bone can be scary for them and parents alike. To help make things a little easier if a spill results in a fracture, here's the lowdown on what to expect.
Broken Bones Bones are tough stuff - but even tough stuff can break. Find out what happens when a bone fractures.
The Facts About Broken Bones What happens when you break a bone?
Cool Cast Facts Some injuries will heal best if a cast or splint is used. Find out how they work and how to take care of them in this article for kids.
Broken Bones, Sprains, and Strains Broken bones and torn muscles, ligaments, and tendons happen. Find out what to do if your child experiences any breaks, strains, or sprains.
iGrow iGrow
Sign up for our parent enewsletter