Everything You Need to Know About Urticaria
Many people suffer from urticaria and Arkansas Dermatology is happy to be able to help these patients.
What is urticaria?
Urticaria, commonly known as hives, consists of red swollen patches of rash that are usually associated with itching. Each individual spot of rash will move within a 24-hour period but sometimes the overall rash will last longer. Hives are caused by histamine containing cells (mast cells) in the skin.
What are the symptoms of hives?
Urticarial lesions itch, have a central white wheal that is elevated, and are surrounded by a red halo. The lesions are typically rounded and well defined. Characteristically, hives should blanch with pressure and often resolve within 24 hours. Hives characteristically are red and itch intensely.
Angioedema, a more severe form of urticaria, results from the same processes that cause hives. Angioedema can be life threatening if not treated urgently because it can affect an individual's airway.
What causes hives?
When an allergen (for example, a food) to which the person is allergic enters the bloodstream through the skin or gastrointestinal tract, it binds to the IgE, and mast cells become activated then release histamine. Allergens that can cause urticaria include foods, drugs (particularly antibiotics like penicillin), and venoms from bee, wasp, yellow jacket, hornet, or fire ants. Virtually any allergen/substance that can be disseminated throughout the body has the potential to cause hives.
If an allergic reaction causes hives or swelling, it is usually ingested (food, medicine) or injected (drugs, bites & stings). If an allergen can penetrate the skin locally, hives will develop at the site of contact. One common example is latex gloves and contact urticaria. This can occur following exposure to latex gloves if sufficient latex penetrates through the skin. In many cases, despite extensive looking for the allergen, one cannot be found.
How long will I suffer from hives?
Most cases of urticaria last less than six weeks. When the time is short, the process is considered “acute” (i.e., short term). If urticaria persists beyond 6 weeks, it is designated “chronic” (i.e., long term). The causes and mechanisms of hives can be different in each patient, as is the prognosis and treatment options.
Chronic Spontaneous Urticaria (CSU)
Chronic urticaria is defined as the presence of hives, angioedema, or both for more than 6 weeks duration. Chronic hives can occur daily or almost daily. CSU may come and go with time and can fully reoccur after months or years of full remission. Typically, CSU has no discernable food or medication causing it. The lesions can vary in shape or size but are like acute urticaria. Angioedema is present as well in about 40% of cases and may involve the lips, tongue, or pharynx. The spontaneous remission rate is 65% within 3 years, 85% within 5 years, and 98% within 10 years.
Are hives related to autoimmune disease?
Patients with CSU have an increased frequency of Hashimoto's thyroiditis, a common thyroid disease. This association between thyroid disease and urticaria is not completely understood. Specific antibody testing is warranted to determine if there is an association between urticaria and thyroid disease in appropriate patients. The overall incidence of thyroid autoantibodies in patients with chronic urticaria is approximately 24%.
How we treat patients with hives
Identification of causative allergens, from the clinical history and blood testing or skin testing will enable the individual with urticaria and angioedema to avoid flares. Where a reaction to medication has been implicated, for example, NSAID's or antibiotics, the physician should identify alternative drug groups for future treatment, or simply remove the medication all together.
Acute attacks of urticaria or angioedema can be treated with H1 antihistamines, such as Claritin, Zyrtec, or Allegra. If urticaria and angioedema have occurred previously resulting in a systemic anaphylaxis reaction, the patient should be prescribed an Epinephrine pen to always carry.
Often an episode of hives will occur without any explanation or lasting clinical significance and will not reoccur again. Patients that have little or no relief with using antihistamines can be treated judiciously with corticosteroids.
First generation antihistamines are sometimes used in combination with 25-50 mg Hydroxyzine or Diphenhydramine (Benadryl) at bedtime. This additional antihistamine regimen can help with sleeplessness or residual itch if urticaria is otherwise controlled. H-2 receptor antagonists (Pepcid or Zantac) and leukotriene antagonists (Singulair) are no longer recommended; there is lacking evidence of efficacy beyond the placebo effect.
When the response to antihistamines is unsatisfactory, the agent of choice is Omalizumab (Xolair) administered as a 150 mg or 300 mg subcutaneous injection monthly in the Dermatology office.
We know that antihistamines successfully treat 45% of hives patients, and Xolair is successful in treating the remaining 55%, then it is estimated that both drugs should be effective in about 83% of patients with CSU. When a response to Xolair is not seen, the next drug of choice is cyclosporine. Dapsone, sulfasalazine, hydroxychloroquine, IV gamma globulin, and methotrexate are all second to third line treatments for hives if Xolair treatment is unsuccessful. Corticosteroids can be used acutely, but not chronically, for particularly severe episodes.
How can I make an appointment to get treatment for my hives?
Arkansas Dermatology offers same-day or next-day appointments for conditions like hives! Contact us today to see an urticaria expert and get your hives under control.
You can contact our office at 501-791-7546 or schedule an appointment online here.