Cast care: Do’s and don’ts

Date Updated: 04/11/2025

If your child breaks a bone, a cast can help support and protect the injury as it heals. But a cast can't do its job without proper care. Learn about the basics of cast care.

What are the different types of casts?

Casts are custom-made to fit and support injured limbs. There are two main types of casts:

Plaster casts. Plaster casts are easier to mold for some uses than are fiberglass casts. Plaster casts also generally are less expensive.
Fiberglass casts. These plastic casts tend to be lighter and more durable than plaster casts. Also, X-rays can see through fiberglass casts better than plaster casts. So it's easier for a healthcare professional to examine your child's bones when a fiberglass cast is used.

What can be done to reduce swelling?

Swelling can cause your child's cast to feel tight and uncomfortable. To reduce swelling:

Raise the affected area. For the first 24 to 72 hours after the cast is applied, use pillows to raise the cast above the level of your child's heart. If the cast is on a leg, your child may need to lean back on cushions or lie down.
Apply ice. Loosely wrap an ice pack covered in a thin towel. Then place it around the cast at the general location of the injury. Ice that's packed rigidly and only touches the cast at one point won't be as effective. Be sure to wrap the ice so that the cast doesn't get wet.
Keep moving. Encourage your child to move the fingers or toes of the injured limb often.

What can I do if my child wants to scratch under the cast?

A cast can cause the skin underneath it to feel itchy. To relieve itchy skin, turn a hair dryer on a cool setting and aim it under the cast.

Don't allow your child to stick objects inside the cast to scratch the skin. This could cause an injury or infection.

Is it OK to get a cast wet?

In general, casts are meant to stay dry. A wet cast can lead to skin irritation or infection. But whether a cast can get wet may depend on the type of cast your child has.

Plaster casts and fiberglass casts with conventional padding aren't waterproof. Keep your child's cast dry during baths or showers by covering it with two layers of plastic, sealed with a rubber band or duct tape. Avoid swimming while wearing a cast that isn't waterproof.

A fiberglass cast that has a waterproof liner can get wet. Only certain types of breaks can be treated with a waterproof cast and liner. Ask your healthcare professional if it's safe to get the cast wet.

If the cast does get wet, you might be able to dry out the inside padding with a hair dryer. Use a low heat setting to avoid burning or irritating the skin.

How can my child keep a cast in good shape?

Try these tips to keep your child's cast in good shape:

Keep it clean. Keep dirt and sand away from the inside of your child's cast.
Skip toiletries. Avoid placing powder, lotion or deodorant on or near the cast.
Leave adjustments to your child's healthcare team. Don't pull out the padding in the cast. Don't trim the cast or break off rough edges without first asking your child's healthcare professional.

What else do I need to know about my child's cast?

Contact your child's healthcare team right away if your child:

Feels increasing pain and tightness in the injured limb.
Feels numbness or tingling in the injured hand or foot.
Feels burning or stinging under the cast.
Develops excessive swelling below the cast.
Can't move the toes or fingers on the injured limb, or the toes or fingers become blue or cold.
Says the cast feels too tight or too loose.
Develops raw skin or has a change in skin color around the cast. This change may be a shade of red, purple or brown depending on your child's skin color.
Develops a crack, soft spots or a foul odor in the cast.
Gets the cast soaking wet and doesn't dry it properly.

Caring for a child's cast isn't always easy. Remind your child that taking care of the cast will help lessen discomfort during the healing process.