Epithelium is a major component of the skin and mucous membranes, providing a barrier to protect the body from infection, dehydration, and other environmental hazards. The cells that make up epithelium are constantly shed and replaced, making it a highly dynamic tissue. The ferret is a popular pet in the United States, and many people are allergic to their dander. The allergen is a protein that is produced by the sebaceous glands in the skin and is present in the urine, saliva, and sweat of the ferret. When these substances come into contact with the human body, they can cause an allergic reaction. The symptoms of a ferret allergy are similar to those of other allergies, such as asthma, hay fever, and hives. The allergen can also be inhaled, causing wheezing, chest tightness, and shortness of breath. Some people may also experience anaphylaxis, which is a potentially life-threatening reaction. There is no cure for a ferret allergy, and the only way to prevent the symptoms is to avoid contact with the animal.