A skin reaction refers to any change in the skin's appearance or sensation in response to an external factor. This can include redness, itching, swelling, or rashes. Common triggers for skin reactions include allergens, irritants, infections, or certain medications. Skin reactions can vary in severity and duration, depending on the cause. For example, a mild reaction may resolve quickly after removing the irritant, while more severe reactions, such as those caused by allergic reactions or infections, may require medical treatment. Understanding the cause is essential for effective management and prevention.