Hives, also known as urticaria, and angiodema are skin conditions that lead to the appearance of welts, expains Mayo Clinic. Hives occur on the surface of the skin, while angiodema affects deeper layers of skin. Food and medication allergies, underlying medical conditions and environmental factors can trigger skin welts related to hives or angiodema.
Shellfish, peanuts, eggs and milk are some of the foods that can trigger allergic reactions that lead to welts on the skin from hives or angiodema, notes Mayo Clinic. Pet dander, pollen, latex and insect stings are other common allergens that can cause welts on the skin. People who have had blood transfusions or have immune disorders such as lupus or HIV are also at risk of developing skin welts. Aspirin, ibuprofen, naproxen and blood pressure medications are common causes of hives and angiodema leading to welts.
Environmental factors such as exposure to sunlight, heat, cold, pressure on the skin and anxiety also cause welts on the skin from hives or angiodema, according to Mayo Clinic. People who are unsure of the cause of their welts should keep a diary of foods, medications and activities in order to narrow down potential causes. Most cases of hives and angiodema clear up in a short period of time, but angiodema accompanied by swelling that restricts the airways can be life-threatening.