intro Hives is a common skin disease that occurs mostly as an allergic reaction to environmental factors or food. But in some cases, hives may also be caused by more serious health problems. Hives appear as bumps or red spots on the skin and are a sign of the body's reaction to allergens. Allergic symptoms are like hives. Definition and symptoms of hives. Hives appear as red and itchy bumps on the surface of the skin. These bumps can be small or large, and in severe cases they can reach the size of a dinner plate. The itching caused by hives is usually intense and may be accompanied by a burning sensation. Urticaria is divided into two main categories: acute urticaria and chronic urticaria... 1... **acute urticaria**: this type of hives lasts less than six weeks and is usually caused by a temporary allergic reaction. Sun, exercise, or even perspiration are triggered.. Symptoms of these hives usually appear within an hour of exposure to the irritant... Hives and Rashes Urticaria and rash are two terms related to skin diseases, but each has its own characteristics.. A rash is any abnormal change in the skin that may include redness, swelling, or itching.. Urticaria is one type of rash, but not all rashes are hives. Anyone can get hives during their lifetime.. People who are allergic to allergens are more susceptible to hives... Also, people who have asthma, allergic rhinitis or atopic dermatitis are more susceptible to hives, especially in childhood.. In addition, severe stress can also cause hives... ### Symptoms of acute hives Acute hives can appear anywhere on the body and usually appear as red, itchy bumps.. Some common symptoms of acute hives include: - Red bumps that turn white when pressed. Chronic hives are similar to acute hives in many ways, but may occur for a longer period of time. Some of the characteristics of chronic hives include: - Change in the size and shape of hives..... - Periodic appearance and disappearance of hives..... - Increased symptoms caused by heat, exercise or stress..... ### Causes of hives ### 1 .... Causes of acute urticaria Acute urticaria usually occurs as an allergic reaction to various substances such as food, drink, medicine or contact with stimuli. The immune system reacts to allergens by releasing substances such as histamine and causes hives symptoms. Also, infection, stress and physical pressure on the skin can also cause chronic hives. Chronic hives are not usually caused by allergies and may be caused by bacterial or viral infections or immune system problems such as lupus. From the cases of cause Chronic urticaria is not known exactly and they are called idiopathic urticaria... Although these hives may last for a long time, they are usually not a serious threat to a person's life... Is hives contagious? As a skin disease, urticaria is not contagious... but if a person develops hives due to contact with irritants such as poison ivy, they may transmit the allergen to others... This transmission is only possible until the allergen has not been removed from the person's skin... Diagnosis of urticaria Diagnosing hives is done through a clinical examination by a doctor and examination of external symptoms... To diagnose the exact cause of hives, in some cases, an allergy test may be performed. Two common types of tests to diagnose hives are: 1.... **Skin tests**: In this method, all kinds of allergens are tested on the skin, and if an allergic reaction to that substance occurs, it is diagnosed.... 2.... **Blood test**: In this test, the presence of specific antibodies in the blood is checked.... Excessive production of antibodies can cause hives.... ### Complications of hives In severe cases of hives, a person may experience anaphylaxis. Anaphylaxis is a severe allergic reaction that can quickly block the airways and be life-threatening.. Certain foods such as peanuts and bee stings are usually the main causes of anaphylaxis. Acute hives usually go away on their own after a few years or even months. Ongoing treatment and medical care are needed to control symptoms and prevent recurrence.