Diagnosing and Treating Chronic Idiopathic Urticaria
Chronic urticaria (hives) continues to be a challenging disorder for dermatologists and allergists. Some patients go through years of hopping from one doctor to another, searching for a cause of their recurring welts (hives), itching, and often, swelling (angioedema). The frustration many people go through is immeasurable, as they endure a disease that is sporadic, prolonged and cosmetically embarrassing.
Chronic idiopathic urticaria (CIU) is a form of chronic hives, the cause of which remains unknown despite a full evaluation and laboratory testing. It is referred to as “chronic” once it lasts for six or more weeks either intermittently or continuously. CIU is rarely life-threatening, but the impact on the quality of life cannot be overstated. Work productivity, sleep quality, classroom attentiveness, social activities, sports and inter-personal relationships may all be affected by CIU.
The bad news is doctors may not be able to figure out the cause of your recurring hives, but the good news is they can assist you with controlling them, as long as necessary.
The workup for chronic hives includes a detailed history and physical exam. I discussed the difference between acute and chronic urticaria in a previous posting. CIU is a diagnosis of exclusion. Your doctor will first attempt to identify a food, drug, or another external trigger by asking several questions about the period leading up to the onset of hives. Other underlying medical conditions can be associated with hives. Therefore the history and physical exam will focus on identifying signs or symptoms of these conditions (for example thyroid disease, lupus or other connective tissue diseases).
CIU is often over diagnosed because various triggers evade recognition by the patient or doctor. Cold, heat, vibration, scratching and pressure may trigger hives and recur over months to years because of repetitive exposure to one or more of these physical factors. If an external trigger is identified and confirmed, it is not CIU. But CIU may coexist with other types of urticaria. Physical Urticaria is a term used for hives caused by one or more of the above (underlined) triggers.
Research on CIU has identified a subgroup of patients that have a special autoimmune disorder that involves the development of auto-antibodies. There is evidence that in 30 to 50 percent of CIU patients, auto-antibodies account for hives and swelling. The auto-antibodies target IgE antibody, or the receptors for IgE antibodies located on cells (mast cells) that underlie the skin and lining of the mouth, throat, respiratory and gastrointestinal tract. These auto-antibodies can activate mast cells and subsequently cause the release of histamine.
Making the diagnosis of CIU
Your doctor will determine if you have CIU after full evaluation and review of lab results. You may be asked to keep a food diary for a month or two, to look for patterns associated with specific foods or beverages (if you have some flare-ups of urticaria in the interim time).
A special blood test to confirm auto-immune CIU is available but not often positive. If you are diagnosed to have CIU, treatment will focus on suppressing hives, itching, and swelling.
Stepped Care Levels of Treating CIhe first line of treatment for CIU is a long-acting, non-drowsy (or low risk for drowsiness) antihistamine. Some examples include:
Second line therapy is considered if first line therapy fails. Your doctor may consider increasing the dose of one of the above medications (often above-recommended doses on the label of the medication). Risks of the above label use of these medications should be reviewed with your doctor.** Never use more than the labeled dose of medication without consulting your doctor.
Third line considerations include adding other types of histamine blockers with the above medication such as:
- Ranitidine (Zantac)
- Cimetidine (Tagamet)
Alternative considerations include starting a short-acting, sedating antihistamine at bedtime:
- Hydroxyzine HCl
Another option for doctors to consider would be to start medication that blocks both types of histamine receptors (combination of first line and third line):
Doxepin is a medication more often used as an anti-depressant, but allergists and dermatologists have used it, at much lower doses than needed to treat depression.
Sometimes a medication used to treat asthma is prescribed for the treatment of CIU. Montelukast (Singulair) is a non-steroidal anti-inflammatory drug that may be taken once daily, and along with some of the above medications, may reduce episodes of CIU.
Severe flare-ups of CIU may warrant a short course of an oral steroid (Prednisone or Methylprednisolone) or an injection of steroid. Most flare-ups will respond to steroids, but a plan must be in place to control CIU once the steroid is stopped.
Omalizumab (Xolair) was FDA approved for treatment of chronic idiopathic urticaria in March of 2014. Monthly injections of Xolair, a hybridized monoclonal antibody (combination of mouse and synthetic human antibody) may reduce the development of hives by clearing out circulating IgE antibody.
CIU adequately responds to antihistamines about 50% of the time. Second and third line treatment measures, as well as other alternative therapies, have helped an additional percentage of patients, but more research is needed in order to better serve those who continue to suffer. There is no cure for CIU but fortunately, as outlined above, there are several treatment options available to prevent flare-ups.
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