Hives & Swelling
Contact dermatitis is an inflammation of the skin caused by contact with substances. It causes an itchy, red rash and at times, blisters. Substances in soaps, cosmetics, jewelry and plants are known triggers. Patch testing is the diagnostic test of choice. Once the offending allergen is identified, avoidance of products containing the substance is necessary.
Hives (urticaria) are red, raised, itchy bumps/wheals on the skin. Many patients with hives also present with swelling (angioedema). Angioedema is deep swelling usually around the eyes, lips, tongue and sometimes the hands and feet. Episodes of urticaria and angioedema are most commonly due to viral infections in children.
Recurrent (chronic) hives and swelling, lasting more than 6 weeks, are classified as chronic urticaria and angioedema. In most cases, the cause is unknown (idiopathic). In a few cases, it may be due to an autoimmune process. Occasionally, hives are the result of an exposure to or ingestion of certain allergens, including foods, medications or insect stings.