What should you know about plaster of paris set?

When plaster of Paris has set, it has hardened enough to support the treated area, but it still needs careful protection. Setting is not permission to test the cast, walk on it, or change its position. Your clinician decides when movement or weight is safe for the injury.

Plaster of Paris is mixed with water and shaped around padding or a support. It changes from a workable material into a firm shell. During that change, heat can be felt. The cast may continue drying after it feels firm, and trapped moisture can weaken it or irritate the skin. A set cast should hold its intended shape without being squeezed or reshaped.

The material can be used for support after an injury and for gradual correction in some orthopedic care. Learn more in Plaster of Paris, Fracture Casting, and Clubfoot Casting.

Rest the cast on a soft surface while it dries, keeping the limb in the position advised by your clinician. Keep the cast uncovered and dry, and use only the prescribed sling, crutches, or other aid. Do not push fingers, pens, or powders underneath it. Move exposed joints only as instructed, and attend the planned review so the fit and skin can be checked.

Arrange prompt medical advice if the cast remains soft, becomes misshapen, cracks, rubs the skin, or develops a persistent wet or unpleasant smell. Get urgent help for escalating pain, severe swelling, tingling, numbness, unusual coldness or colour in fingers or toes, or loss of movement. Do not wait for the cast to dry if circulation or nerve symptoms appear.

Ask how long the cast should be protected from pressure, when you may bear weight, how to keep it dry, and which symptoms mean you should contact the clinic immediately.