Whether you have spent a long day in the swimming pool or a relaxing hour in the bathtub, you will likely find that your fingers and toes look like wrinkled prunes. Caused by excess water absorption, this pruning is generally quite harmless and resolves itself quickly. Occasionally, however, pruned skin is accompanied by an intense itch. Itchy skin from pruning in water can be caused by several different factors.
Water & Pruned Skin
After spending a long period of time in a bathtub or swimming pool, most people experience an unusual wrinkling of the skin on the fingers and toes. The outermost layer of the skin, the epidermis, produces a layer of oil that moisturizes and protects the skin. After long periods of time in the water, this oil washes away and the water is able to penetrate the skin. As water enters, the skin must expand to accommodate the extra volume. However, since the skin is firmly attached to the underlying tissues, it cannot simply expand outward. Instead, the skin must wrinkle to provide extra surface area.
Itchiness & Pruning
According to the Library of Congress website, some scientists speculate that the blood vessels inside the hands and feet constrict when submerged in water. As these blood vessels narrow, less blood flow is directed toward the digits. In some people, this may result in brief episodes of itchy skin. However, most people do not experience itchy skin simply as a result of pruning in water.
If a red rash or small bumps accompany the pruned skin, the itchiness may be caused by an allergic reaction. Skin allergies vary widely from one person to the next. While some people have no skin sensitivities, others find themselves reacting to common household ingredients. Consider the possibility of an allergy to soaps or bubble bath formulas used in the bathtub or chemicals used to clean the swimming pool. Although these substances may not cause an immediate allergic reaction, they might lead to itchy skin after prolonged exposure. And if you are staying in the water long enough to develop pruned skin, your skin has likely been exposed to the substance the entire time. If itchy skin only accompanies your pruned and waterlogged skin after using a specific type of water or product, an allergic reaction is likely the cause.
Although rare, some people suffer from an allergy to water. According to the National Institutes of Health Office of Rare Diseases Research, the condition known as aquagenic pruritus "is a condition in which contact with water of any temperature causes intense itching without any visible skin changes." Although the itchiness might occur within one minute of water exposure, it can also occur more than 15 minutes after exposure. In some cases, the itchiness might not occur until after your skin has pruned. On average, the itching lasts roughly 40 minutes. As of December 2010, the cause of aquagenic pruritus remains unknown and proper treatments are still being researched.
Cold urticaria refers to an allergic symptom related to cold temperatures. Although symptoms typically appear soon after exposure to cold temperatures, the Mayo Clinic explains that "symptoms of cold urticaria are often worse during rewarming of the exposed skin." A person with cold urticaria may be submerged in cold water without any symptoms. However, once the skin has pruned and the body begins to warm up, the ichy skin may then develop. Other symptoms of this cold allergy include red hives on the skin and swelling of the hands and feet. Typically, the itchy hives will spread to all areas of the body exposed to cold temperatures.