This is the onset of wheals commonly called “hives” which occur on the skin. They are extremely itchy and are sometimes associated with swelling of parts of the face, hands or feet.
It is not a life –threatening reaction unlike anaphylaxis although you can get urticaria as a feature of anaphylaxis.
Urticara can occur on any part of the body.
It is broadly divided into two types.
- Acute Urticaria: This usually alst for 6 weeks but in most cases will last even less than that.
There are three main causes of acute urticarial
- Allergy : This may be caused by a reaction to food or drugs. It occurs within minutes to an hour after exposure ot the food or drug. It can be mild, moderate or severe and usually last for a few hours.
- Infection : Urticarial can occur as a reaction to an infection. The infection can be a viral, bacterial or parasitic infection. The urticarial can occur during the incubation period of the infection, at the height of the infection or it may occur 1-2 weeks after an infection. It can last for a few days to weeks.
- Contact Urticaria: This is a rare form of urticarial that occurs as a reaction to a cream or ointment on the skin.
Antihistamines are the main treatment for these patients. Some may need a short course of oral steroids for control of symptoms.
- Chronic Urticaria (CU): This usually last for longer than 6 weeks. There are two broad categories of CU.
- Physical (Inducible) Urticaria
- Chronic Spontaneous Urticaria.
Physical (Inducible) Urticaria.
There are many types of physical urticarias. .
The most common causes of inducible hives include:
- Scraping or stroking– People who get this type of hives develop red, raised lines on their skin along areas that have been scraped or stroked. Doctors call this “dermatographism.” The linear rash takes the form of the stimulation on the skin. (picture)
- Cold– People who are sensitive to cold get hives when their skin starts to warm up again after being cold.
- Increased body temperature or sweating– People who are sensitive to heat or sweat get lots of tiny hives, often when they cool off after a hot shower or cool down after exercising hard.
- Vibration– People who are sensitive to vibration get hives on parts of their body that have been touching something that vibrates. If you get this type of hives, you might get them on your palms after you have been driving and holding onto a steering wheel, or after mowing the lawn.
- Pressure– People who are sensitive to pressure can get redness and swelling anywhere on their body that has been pressed on. The swelling can start hours after the pressure. For example, if you have this problem, you might get a swollen palm a few hours after carrying a heavy bag by the handles. Or you might also get swelling of the soles of the feet after walking a long way.
- Exercise– Hives that show up during exercise can be a sign of a dangerous problem called exercise-induced anaphylaxis. If the hives show up after exercise, when cooling down, they are more likely to be the type triggered by changes in body temperature or sweating.
- Sunlight or water– Hives caused by sunlight or water are rare.
There are specific test that can be done for these forms of urticarial. These are done by an allergy specialist. Inducible hives tend to go away and come back over a period of years.
Most inducible urticarial symptoms can be avoided by avoiding the causes. Most patients respond well to antihistamines. Some patients may require a high dose of anthistamines. Steroids generally do not work for inducible urticaria and should be avoided.
Chronic Spontaneous Urticaria (CSU)
This affects about 1% of the population. It last for longer than 6 weeks and occurs without any known external cause however some patient`s symptoms may be triggered by various factors. These patients have almost daily symptoms for more than 6 weeks. The symptoms significantly affect the quality of life of patients. Many experience sleep disturbances and are unable to work because of the severity of their symptoms.
This is an autoimmune disease and not caused by an allergy. Many patients complain that certain foods aggravate their symptoms. These may be aggravating factors but not associated with an allergic reaction.
CSU is never a life threatening condition. It is not anaphylaxis which is a completely different condition.
CSU if often associated with other autoimmune disease like hypothyroidism and lupus.
The urticaria can be aggravated with external stimulation. However the majority of patients have symptoms without any external aggravating factor.
Some of these factors are:
- NSAIDS: These are are commonly used drugs such as Ibuprofen ( Nurofen), Ponstan , Voltaren, Aspirin and many others.
- Environmental factors like heat, cold and sunlight.
- Friction on skin from clothing
We do not routinely perform tests in patients with CSU. We sometimes do blood test to look for underlying infection or other autoimmune diseases. In patients in whom there is a doubt about the diagnosis, we sometimes do a skin biopsy.
We treat patients with non-sedating anti-histamines. There are many brand names. We often give high doses of these antihistamines to get symptom control. We can use up to 4X the normal dose for symptoms control.
These medication have severe side effects if used for long durations. We rarely use them to treat Urticaria. We sometimes use them for short courses for quick control of symptoms.
This is a monoclonal antibody injection we give to patients who do not respond to high doses of anti-histamines. It is highly effective and extremely safe. It can completely resolve symptoms in most patients. About 20% have a poor response. Many of these patients require doses every month for at least 6 months and some even longer. The problem is the high cost of this injection.
Most patients will have spontaneous resolution of their symptoms by one year. About 50% will have no symptoms by one year. Many will have symptoms for 3-5 years.