Waterproof casts offer convenience for activities like showering or swimming, but they are not maintenance-free. While the outer shell is designed to repel water, the special internal liner and the skin underneath must be dried properly after getting wet. Failing to thoroughly dry the cast creates a damp environment where bacteria and fungi can thrive, leading to complications.
Understanding Waterproof Casts
A waterproof cast is typically made from a fiberglass or plastic exterior, which is inherently water-resistant and structurally sound when exposed to moisture. However, the lining material immediately surrounding the skin, known as the waterproof liner, is designed to allow water to pass through and drain out. The primary goal of the drying process is not to dry the rigid outer shell, but to remove the moisture from this inner liner and the skin surface. If the liner remains damp for too long, it can lead to skin breakdown, a condition called maceration, creating an environment ripe for irritation and infection.
Essential Techniques for Thoroughly Drying the Cast
The first step after submerging the cast is to allow water to drain out using gravity. Hold the casted limb in a position that encourages water to flow freely from the open ends. Wiggling the fingers or toes can also help to displace any trapped water within the liner. It is recommended to flush the cast with a steady stream of clean, fresh water after swimming or bathing to remove any chlorine, soap residue, or debris.
Once the bulk of the water has drained, use air circulation to facilitate evaporation. Place the casted limb near a standard fan on a low setting, allowing a continuous flow of ambient air to pass through the cast openings. This method encourages the slow, safe evaporation of moisture from the liner and skin without creating excessive heat. Air drying times vary widely depending on the cast’s location and ambient humidity, potentially taking a few hours to feel completely dry.
For a more targeted approach, a hair dryer can be used, but only on the COOL or LOW setting. Direct the cool airflow into the open ends of the cast, moving the dryer constantly to ensure the air circulates throughout the entire space. Avoid using high heat settings, as this can easily burn the sensitive skin underneath the cast, which cannot be immediately inspected. High heat can also compromise the integrity of the cast’s lining material.
Warning Signs and When to Contact a Doctor
Even with careful drying, certain symptoms indicate a problem requiring professional medical attention. The most common warning sign is a persistent, foul odor emanating from the cast, suggesting bacterial or fungal growth due to retained moisture or infection. Intense, localized pain, burning, or a stinging sensation that does not resolve after elevation or applying cool air may indicate skin irritation or pressure from a damp, tightened liner. Look for signs of skin maceration, where the skin around the cast edges appears white, pruned, or unusually soft, signaling that the tissue has been wet for too long. Contact a healthcare provider immediately if you notice any discharge or pus seeping from the cast openings, or if the cast feels suddenly too tight after getting wet, which may signal excessive swelling underneath.