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Hives - Critical Uticaria

The Asthma Center, Allergic Disease Associates, P.C.
Professional Arts Building
205 North Broad Street, Ste 300
Philadelphia, PA 19107

215-569-1111
http://www.asthmacenter.com

What is Urticaria?

Urticaria is a very itchy rash commonly known as hives. Urticaria can affect approximately 20% of Americans at some time in their lives. Typically hives are slightly raised red or pale areas on the skin that range in size from pinpoint to many inches in diameter. They can involve any part of the skin, including the face, hand, extremities and trunk. It can occasionally occur in the mouth. Individual hives can join together to form large itchy, red areas that are called “giant hives.” A single hive can disappear within a few hours leaving the skin without a trace, only to be replaced by new hives. If Urticaria causes inflammation or discoloration of the skin that lasts more than 24 hours, then an underlying non-allergy related medical problem may be the cause.

When swelling of the deep skin tissue is associated with hives, it is called angioedema. Angioedema occurs in about half of people who have chronic Urticaria. Angiodema or swollen soft tissue that is not associated with hives is not usually itchy. It can involve the lips, eyes, hand, foot, throat, genitals, or rarely internal swelling causing abdominal pain. Throat or tongue swelling can be a life-threatening emergency as it can cut off air supply. Individuals at risk should be prepared for this event with a clear emergency plan and appropriate medications.

What is different about Chronic Urticaria?
A sudden onset of Urticaria, which lasts a short time, is quite common. Often the rash will only last hours and may resolve within hours or days. Usually there is a clear cause or association with food, an insect sting, a new medication, contact with a pet, or some other specific cause. However, chronic Urticaria or persistent hives is different. It is defined as Urticaria that occurs at least 3 times a week for more than weeks in a row. Unfortunately, 80-95% of cases of chronic Urticaria cannot be linked to any specific allergy trigger, even after extensive investigation and the involvement of qualified specialists. Therefore, chronic Urticaria can occur without clearly being caused by food, medicine, animal allergy, pollen, dust, chemicals, or any other identified factor. Testing for possible cause is performed at The Asthma Center for individuals with chronic Urticaria in order to correctly diagnose allergy in people who do have allergic urticaria. If you are diagnosed with chronic non-allergic Urticaria, it is usually not necessary to begin diet restriction or an extensive home cleanup . Fortunately even Urticaria without a clear cause often can be treated successfully with proper medication.

What causes chronic Urticaria?
No exact external or environmental trigger has yet been found for most cases of chronic Urticaria. For decades, physicians and non-physicians alike have often attributed Urticaria of all types to “stress” or “nervousness.” While stress can worsen or trigger Urticaria in some people, it is now known that the cause of Urticaria may be more complex and not usually caused by stress, anxiety, psychological factors.

In some individuals, chronic hives are the result of the individual producing hives against his/her own tissues and not due to any external factors. In approximately 25% of people with chronic Urticaria, laboratory tests reveal an antibody against a receptor on the mast cell (an allergy-related cell that is present in the skin.) Antibodies can trigger releases of substances from the mast cell such as histamine that induces redness, itching and swelling. Research shows that some individuals with chronic Urticaria (Hives) share similar genetics with people who have autoimmune diseases such as rheumatoid arthritis. It is also known that people with chronic Urticaria are more likely that people in the general population to have antibodies against the thyroid gland. Thyroid antibodies can cause hypo-thyroidism (under or overactive thyroid.) Several studies have shown that people with chronic Urticaria associated with thyroid antibodies had improvement in their Urticaria when treated with thyroid hormone. This therapy is reserved for unusually difficult-to-treat Urticaria. It is important to note that most people with chronic hives DO NOT have any other autoimmune disease and are usually completely healthy.

Physical Urticaria
One type of chronic Urticaria is Physical Urticaria. This is defined as Urticaria (Hives) which occurs following exposure to a physical factor such as heat, cold, exercise, physical pressure, sun or water. Physical Urticarias include:

Dermatographism: Dermatographism is the presence of line-shaped redness, itching and swelling that occurs within minute after the skin is stroked, such as with scratching or with light pressure such as occurs with tight areas of clothing or belts. These lesions usually disappear within less than 20 minutes. Dermatographism can occur alone or with chronic Urticaria.

Cholinergic Urticaria: Cholinergic Urticaria is common. In this kind of Urticaria small pinpoint hives are induced by heat exposure or activities that cause an increase in body temperature. This often responds to treatment and may resolve after two to three years.

Cold Urticaria: Cold Urticaria is triggered by exposure to cold liquids or solids such as cold foods or drinks, snow, ice, or even, air-conditioning. While most people with cold Urticaria have hives that respond easily to treatment, rarely underlying diseases can be present. Swimming is cold water can result in life-threatening allergic reactions for someone with Cold Urticaria. If you have this condition, DO NOT SWIM ALONE, and have a plan and medical supplies for emergency treatment.

Delayed Pressure Urticaria: Delayed pressure Urticaria is actually angioedema. Large areas of often painful deep tissue swelling occur hours after physical pressure. Triggers include manual labor or standing on a hard surface such as rocks. Delayed pressure Urticaria is often difficult to treat.

What treatment and testing can I expect?

If you have Urticaria, physicians at The Asthma Center will advise testing to rule out allergy. This is important because allergic urticaria requires different treatment from non-allergic chronic Urticaria. Any medication that you may have taken during or prior to Urticaria episodes should be investigated as a cause of your Urticaria. This may require you to keep a medication diary. Please be sure to tell your Asthma Center Physician about medications you are taking including over-the-counter medications, herbal supplements, vitamins, and injections.

If no allergic cause is found, testing will be ordered. This will usually include a urinalysis (urine sample), laboratory tests and a chest x-ray. You will be questioned about your general health, including the approximate dates of your last PAP smear, mammogram, stool blood test and general physical. Most people with chronic Urticaria are NOT found to have any underlying disease.

If you are found to have chronic Urticaria, treatment to control your symptoms will be prescribed. This will probably include non-drowsy or mildly sedating antihistamines. It is recommended that these be taken on a regular basis to prevent urticaria, rather than “as needed.” Additional medications may include H2 blockers (Zantac, Tagament, or Pepcid) that work with the antihistamines to suppress Urticaria. Some asthma medications such as Accolate or Singulari, may also be prescribed for urticaria since they can suppress chemicals suppressed by cells that cause hives. If your case is particularly severe, oral corticosteroids such as prednisone or Medrol may be needed. Remember corticosteroids are not meant for long-term use, except in rare cases. Also follow The Asthma Center physician’s directions exactly if given oral corticosteroids, and never stop them if suddenly you have been on them for over one week.. Allergy shots have not been shown to be effective in treating chronic Urticaria.

In occasional cases, Urticaria may be resistant to treatment or testing may suggest an underlying problem. In this case a skin biopsy may be needed. Consultation with a dermatologist or other specialists may be indicated in some individuals. Most people with chronic Urticaria, however, are able to find a treatment regimen that controls or eliminates their hives.