Hives on the skin occur when the immune system reacts to external factors such as stress, sun exposure and excessive pressure on the skin, explains the American Academy of Dermatology. Individuals with bacterial infections, cold viruses and illnesses such as thyroid disease are also at risk of developing hives.
Hives can also be triggered by allergic reactions to shellfish, outdoor pollens, cat dander and certain medications, according to MedlinePlus. Individuals with allergies to nuts and dairy products may also break out in hives following ingestion of the substances. In many cases, hives cause only mild symptoms and resolve on their own without treatment. However, the condition can also trigger anaphylaxis, a life-threatening allergic reaction. It is imperative for individuals to seek medical treatment as soon as possible if hives are accompanied by facial swelling, breathing difficulties or throat tightness.
Hives that cause itching or prolonged symptoms are typically treated with antihistamine medications, explains Mayo Clinic. Severe hives may also be treated with oral corticosteroid medications that work to minimize swelling and relieve inflammation and itching. If these treatments are not successful in relieving symptoms, doctors may recommend autoimmune medications, as this treatment can help to balance out over-reactive immune systems that trigger hives. Individuals with a predisposition for developing hives may be required to carry a self-injection dose of epinephrine with them at all times to ensure immediate treatment of allergic symptoms.