Urticaria (hives) is a common disease that affects one of out of every five people in the general population. It is characterized by red erupted plaques that are severely itchy. Those plaques may develop in any part of the body and it may cause swelling, called angioedema, as it involves deep tissues and mucosa.
Types of Hives
Hives is divided into two types depending on how long the disease persists. The common form that lasts shorter than six weeks is called ‘acute hives’, while ‘chronic hives’ persists longer than six weeks and it is detected in one out of every one hundred people. In case of chronic hives, it is further classified as ‘spontaneous’ or as ‘inducible’ depending on identification of a triggering factor.
Why does Hives develop?
Hives originates from abnormal stimulation of ‘mast cells’ that play a major role in allergy and release of various chemicals, such as histamine, from those cells. Contrary to the popular belief, the factor that stimulate mast cells is not the allergy itself. In case of acute hives, allergic factors are taken into consideration, but allergic elements are not the underlying cause for patients with chronic hives who suffer from symptoms every day.
The most common etiology of acute hives is infections (upper respiratory tract or urinary tract infections) or drugs (painkillers, aspirin or antibiotic agents). For chronic hives, the most common cause is autoimmunity (formation of immune response to native body cells) or in other words, the autoantibodies synthesized by the body to its own allergy cell. Those autoantibodies stimulate the mast cell and cause its discharge. Chronic infections (parasitic infestations, dental infections, chronic otitis, chronic sinusitis etc.), pseudoallergens in foods and drugs play the major role in chronic form of the hives. Considering the inducible hives, potential etiologic factors are dermatographia, cold contact (cold contact hives), pressure urticaria (delayed pressure hives), sweating and increased body temperature (cholinergic), hot contact (hot gives), water contact (aquagenic ghives) sun rays or visible light (solar hives), vibration (vibratory hives) or contact with protein molecules (contact hives).
Most drugs may cause hives, but painkillers, such as aspirin and ibuprofen, codeine, antibiotic agents such as penicillin and cephalosporin, blood transfusions and vaccines may also lead to hives. The antihypertensive agent, called ACE inhibitor, causes hives-free angioedema.
Symptoms of Hives
The major symptom of hives is the red plaque that is itchy, erupted and mobile that disappears in shorter than 24 hours without leaving any scar. Associating dermal swelling (angioedema) is observed in half of the cases. In rare cases, eruptions or plaques are not associated with angioedema (around 10% of the cases). Angioedema most commonly involves eyes and lips. Urticaria plaques can form at any part of the body, but they are more common in regions that are exposed to pressure. Those plaques may be small, but they may conglomerate and their size may increase enough to cover half of the body. Symptoms of the inducible urticaria are different. Linear plaques consistent with scratching are noted in symptomatic dermatographia, while very tiny (in millimeters) eruptions are seen in the cholinergic hives and painful swelling occurs in body parts exposed to pressure in delayed pressure urticaria. In addition to those symptoms, hives may also lead to sleeplessness, impaired attention and social isolation.
How is Hives Diagnosed? Which tests should be done?
Clinical signs and symptoms are mostly enough to make diagnosis of hives. Routine allergy tests are not required. Tests for potentially underlying infections, autologous serum test for diagnosis of the autoimmune hives, examinations for commonly associating thyroid diseases and provocation tests for inducible hives are necessary. In some cases, a skin biopsy may be required if hives plaques persist longer than 24 hours or they leave scar formation while recovering.
How is Hives treated?
Treatment of hives is based on suppression of the symptoms. For this purpose, the most effective drugs are antihistaminic agents. Treatment should be maintained until hives disappear. Disappearance of hives may take 6 weeks in acute hives and 7 years, on average, in chronic hives. However, the condition usually disappears within one year in half of the chronic hives cases. Therefore, quality of the life should be boosted with treatments that suppress symptoms during this period of time. The antihistaminic agents that do not cause sleeplessness and preferred. The dose of antihistaminic agent may be increased up to 4 folds and here, the important point is to take those agents every day, not only when symptoms emerge. If antihistaminic agents do not help the condition even after the dose is increased up to 4 folds, omalizumab, an anti-immunoglobulin E, should be considered. This agent is administered at hospital in the form of monthly injections. For cases that are refractory to omalizumab, it may be necessary to use cyclosporine, a drug that should be used through regular blood drug level monitoring.
What should patients with hives take care of?
- Prefer paracetamol rather than painkillers such as aspirin and ibuprofen.
- Avoid too hot environments.
- Do not consume the foods that contain additives and spices.
- Find a doctor who will follow up you regularly.
- Avoid stress; do not hesitate seeking psychiatric consultation, if required.