MANAGEMENT
Nonpharmacologic therapy
Treatment of the underlying cause, if identified, may be helpful and should be considered. For example, if a thyroid disorder is found on serologic testing, correcting the disorder may resolve the urticaria.9 Similarly, if a complement deficiency consistent with hereditary angioedema is detected, there are medications to correct it, which can be life-saving.3 Medications for treating hereditary angioedema are best prescribed in an allergy practice.
If triggers are discovered, the patient must be made aware of them and advised to avoid them as much as possible; however, total avoidance can be very difficult. Other common potentiating factors—such as alcohol overuse, excessive tiredness, emotional stress, hyperthermia, and use of aspirin and NSAIDs—should be avoided.10 These factors can worsen what is already triggering the urticaria and make it more difficult to treat; an example would be a patient who develops urticaria from a new household dog and is taking anti-inflammatory drugs for arthritis symptoms.
Topical agents rarely result in any improvement, and their use is therefore discouraged. In fact, high-potency corticosteroids may cause dermal atrophy.11 Also, dietary changes are not indicated for most patients with chronic urticaria, because undiscovered allergy to food or food additives is not likely to be responsible.4
Antihistamines
Antihistamines are the most commonly used pharmacologic treatment for chronic urticaria (see Table 4). H2-receptor blockers, taken in combination with first- and second-generation H1-receptor blockers, have been reported to be more efficacious than H1 antihistamines alone for the treatment of chronic urticaria.6 This added efficacy may be related to pharmacologic interactions and increased blood levels achieved with first-generation antihistamines. Increased doses of second-generation antihistamines—as high as four times the standard dose—are advocated by the 2014 Joint Task Force on Practice Parameters (JTFPP) for the diagnosis and management of acute and chronic urticaria.4
A stepwise approach to treatment is imperative. The JTFPP guidelines (available at www.allergyparameters.org) are summarized below.
Step 1: Administer a second-generation antihistamine at the standard therapeutic dose (see Table 4) and avoid triggers, NSAIDs, and other exacerbating factors.
If symptom control is not achieved in one to two weeks, move on to
Step 2: Increase therapy by one or more of the following methods: increase the dose of the second-generation antihistamine used in Step 1 (up to 4x the standard dose); add another second-generation antihistamine to the regimen; add an H2 blocker (ranitidine, famotidine, cimetidine); and/or add a leukotriene-receptor antagonist (montelukast 10 mg/d).
If these measures do not result in adequate symptom control, it’s time for
Step 3: Gradually increase the dose of H1 antihistamine(s) and discontinue any medications added in Step 2 that did not appear beneficial. Add a first-generation antihistamine (hydroxyzine, doxepin, cyproheptadine), which should be taken at bedtime due to risk for sedation.12
If symptoms are not controlled by Step 3 measures, or if the patient is unable to tolerate an increased dose of first-generation antihistamines, the urticaria is considered refractory. At this point, the clinician should consider referral to an allergy specialist for
Step 4: Add an alternative medication, such as cyclosporine (an anti-inflammatory, immunosuppressive agent) or omalizumab (a monoclonal antibody that selectively binds to IgE).
It should be noted that while the recent FDA approval of omalizumab for treatment of chronic urticaria has been life-changing for many patients, the product label does carry a black box warning about anaphylaxis. Because special monitoring is needed (and prior authorization will likely be required by the patient’s insurer), omalizumab is best prescribed in an allergy office.
It is not uncommon for patients with chronic urticaria to require multiple medications to control their symptoms. Once controlled, they will require maintenance and reevaluation on a regular basis.13
When to refer
Clinicians must know when to refer a patient with chronic urticaria to an allergist/immunologist. Referral is indicated when an underlying disorder is suspected, when symptoms are not controlled with Steps 1 to 3 of the management guidelines, or when the patient requires repeated or prolonged treatment with glucocorticoids.
Unfortunately, out of frustration on both the provider and the patient side, glucocorticoids may be started, after determining that that is “all that works” for the patient. There appears to be a limited role for glucocorticoids, so they should be avoided unless absolutely necessary (ie, if there is no response to antihistamines).
If signs and symptoms suggest urticarial vasculitis, it is prudent to consider referral to a specialist in rheumatology. Urticarial vasculitis requires a special skin punch biopsy to confirm the diagnosis.8 The biopsy procedure may be performed by a primary care provider; if the clinician is not comfortable doing so, referral to an appropriate dermatology provider is indicated.