Many potential causes of skin swelling exist. Among the most common are allergies, eczema, and contact dermatitis. A person may also develop skin swelling because of a bacterial infection called cellulitis. In many cases, skin swelling isn’t dangerous. Severe skin swelling and swelling that is caused by a serious infection, however, may prove life-threatening.
Allergies are among the common causes of swelling. When a person has an allergy, his immune system responds to the allergen as if it is a foreign invader. The immune system causes the release of certain chemicals in the body, including one called histamine. When histamine is released under the skin, it causes the skin to swell and may lead to redness and itching. In some cases, this can be life-threatening.
Another common cause of swollen skin is eczema, also referred to as atopic dermatitis. This chronic condition is marked by inflammation of the skin that is accompanied by itching. It is most common in children, but some people do experience it later in life as well. Eczema is often seen in people who have allergies such as hay fever or suffer from asthma. Though it can appear on any part of the skin, the skin on the arms and behind a patient’s knees is the most likely to be affected.
Contact dermatitis, which develops when something that touches the skin causes it to become inflamed, is another common condition that may result in skin swelling. There are numerous substances that can produce this reaction. For example, a person may develop contact dermatitis because of a soap, detergent, or perfume. Some people also develop it after their skin has been in contact with certain types of jewelry or poisonous weeds such as poison oak. The red, itchy rash and swelling caused by contact dermatitis isn’t dangerous and cannot be passed on to others.
An individual may also suffer from swelling of the skin as a result of a condition called cellulitis, which is caused by bacteria. It is marked by swollen, reddened areas of skin that feel warm and sore when touched. This skin infection may start with just one area and then quickly spread to other parts of the skin. Cellulitis can affect any part of a person’s body, but the skin of the legs are the most frequently affected. If cellulitis is not successfully treated in a timely manner, it can threaten the life of the patient.