What is Urticaria?
Urticaria, also known as hives, is a transient cutaneous rash with red, oedematous (swollen)plaques on the skin, which appear suddenly, either as a result of the body’s reaction to certain allergens or for unknown reasons.
Urticaria usually causes itching, but it may also cause a burning or stinging sensation. It may appear on any part of the body, even the face, lips, tongue, neck and ears.
The rashes due to urticaria vary in size, from small to fairly large plaques (from a pencil eraser to a dinner plate), and may join together to form larger areas known as plaques. The duration of the disease may be short (hours, days) or it may last for months to years with periods of remission and flare-ups.
What causes urticaria?
- Certain foods, especially nuts, eggs and shellfish
- Medicines such as antibiotics (penicillin and special sulphonamides), aspirin and ibuprofen
- Insect bites
- Physical irritants, such as pressure, cold, heat, exercise or sun exposure
- Blood transfusions
- Bacterial infections, including urinary system infections and streptococcal pharyngitis
- Viral infections, including common cold, infectious mononucleosis and hepatitis
- Some plants, such as oak and ivy
Symptoms can last from minutes to months – or even years.
While the rashes look like insect bites, hives are different in their appearance and are presented in several ways:
- Hives can appear on any area of the body; they may change shape, move around, disappear and reappear over short periods of time.
- The bumps are red or skin-coloured “wheals” with clear edges – usually appear suddenly and go away just as quickly.
- Pressing the centre of a red hive makes it turn white.
- In any case, individual lesions usually go away within 24 hours.
There are two types of urticaria – acute (short-lived) and long-term (chronic) urticaria.
Neither is typically life-threatening, though any swelling in the throat or any other symptom that restricts breathing requires immediate emergency care (angioedema of the airways).
Chronic urticaria occur almost daily for more than six weeks and are typically itchy. Each hive lasts less than 24 hours. They do not bruise nor leave any scar.
Some cases of hives last for more than six weeks and can last months or years. This condition is known as chronic hives.
If the cause cannot be identified, even after a detailed history and testing, the condition is called chronic idiopathic urticaria.
About half these cases are associated with some immune findings. Chronic hives may also be associated with thyroid disease, other hormonal problems or, in very rare instances, cancer.
How do dermatologists treat hives?
For mild or moderate urticaria, the most common treatment is a non-sedative (not causing drowsiness) antihistamine. Antihistamines relieve symptoms such as itching.
If you have chronic urticaria, the doctor may prescribe an antihistamine. There are many available antihistamines in the market.
Some of these can cause drowsiness, other not. There is no one antihistamine that is effective for everyone. Your dermatologist can combine an antihistamine with other medicines to control urticaria.
Other medicines prescribed for controlling urticaria include:
- Cortisones for short-term use only because of side effects with long-term use.
- Antibacterial agents depending on the cause.
- Other medicines that fight inflammation (redness and swelling).
- Montelukast (Singulair), a leukotriene receptor antagonist.
- Monoclonal anti- Ig E antibody (Omalizumab).