Urticaria is a heterogeneous syndrome, whose primary mark is the hive. It is characterized by swelling with a pink or porcelain-white colour.

The skin lesion forms quickly and disappears without leaving traces within a few hours. It is usually accompanied by itching. Depending on the duration of the disease, urticaria may be described as acute (lasting up to 6 weeks) and chronic (lasting more than 6 weeks). Urticaria affects around 15%–20% of the population, and the risk of chronic urticaria is about 0.5%. Contributing factors include pharmaceuticals, foods, inhaled allergens (such as cat hair), preservatives, infections, and perfumes. Often, however, no specific cause can be assigned (especially in the case of chronic urticaria), which is important information for the patient. It is not unusual for the disease to be exacerbated under the influence of mental stimuli. If it is suspected that urticaria is caused by nutrients, food additives, or preservatives, an elimination diet should be used for about two weeks. If the symptoms withdraw, the diet should be maintained for about 3–6 months. An elimination diet is a regime of water, tea, cheese, rice, potatoes, butter, and lean meat. Avoid dish, cheese, red wine, pickled cucumbers, sauerkraut, spices, strawberries, citrus fruits, and products containing large amounts of preservatives. Other causes of urticarial include bacterial or parasitic infection and Helicobacter pyroli infection. Other types of urticarial occur in response to cold, heat, light, contact, and mechanical irritation. Fundamental to treating urticaria is to conduct a thorough interview with the patient in order to determine and avoid the triggering factors. Second-generation antihistamines are the main group of pharmaceutical agents used in the treatment of urticaria. These include loratadine, cetirizine, levocetirizine, desloratadine, and fexofenadine, safe preparations that can be used for a long time at high doses. In severe cases, immunomodulatory drugs and UV irradiation are used.