The finding that needs evaluation
Two weeks after casting, a warm spot on the cast over the heel with a musty odor is a warning sign. A warm area over a bony prominence, often called a hot spot, suggests inflammation beneath it, and a foul or musty smell suggests tissue breakdown or infection. Together these point to a pressure injury or infection under the cast, so the cast may need to be windowed or removed for inspection.
Why the heel is at risk
Bony areas such as the heel, malleoli, and the head of the fibula have little soft tissue between bone and cast. If the cast fits tightly, has a rough edge or dent, or if swelling changes, constant pressure can reduce blood flow to the skin and cause a pressure injury. Because the skin is hidden, the first clues are often indirect: localized warmth on the cast surface, drainage staining through the plaster, or odor. Early detection prevents a deep ulcer or infection that could delay fracture healing.
| Finding at 2 weeks | Interpretation | Action |
|---|
| Toe swelling after long sitting that subsides with elevation | Expected dependent edema | Continue elevation; teach to avoid prolonged dependency |
| Itching relieved by cool air from a hair dryer | Expected | Continue; do not insert objects under the cast |
| Arm and shoulder ache after crutch walking | Expected muscle fatigue | Check crutch fit; weight on the hands, not the axillae |
| Warm spot over the heel with musty odor | Possible pressure injury or infection | Arrange evaluation of the cast |
Why the other findings are expected
Swelling that develops after long sitting and resolves with elevation is dependent edema and responds to the usual measures. Itching under a cast is common as the skin is enclosed, and cool air from a hair dryer is the recommended remedy. Watch out! The client must never push objects such as sticks or pens under the cast to scratch, because they can break the skin or be lost inside and cause the very pressure injury and infection described. Upper-body ache in the first weeks of crutch walking is expected muscle fatigue, as weight is borne on the hands.
Other cast warning signs to teach
Clients should report increasing or new pain, especially a burning pain over one spot, numbness or tingling, toes that become cool, pale, or bluish, swelling that does not improve with elevation, drainage or staining on the cast, odor, fever, and a cast that cracks, softens, or becomes loose or too tight.
Exam takeaway
Key point! A hot spot or a foul or musty odor from a cast suggests pressure injury or infection and requires evaluation. Itching, swelling that resolves with elevation, and crutch-related muscle ache are expected. Teach clients never to insert objects under the cast.