Final answer:
Allergens and other environmental factors can affect pruritus or itch. Exposure to allergens like pollen and dust mites can trigger itching, as can dry air and harsh chemicals.
Step-by-step explanation:
Pruritus, also known as itch, is the unpleasant sensation that leads to scratching. There are several environmental factors that can affect pruritus. One of the main factors is exposure to allergens. Allergens such as pollen, dust mites, and pet dander can trigger an allergic reaction in some individuals, leading to itching. Other environmental factors that can contribute to pruritus include dry air, harsh chemicals, and certain fabrics.