Urticaria

Diagnosis/Definition:

An evanescent, pruritic rash characterized by a wheal and flare.

Initial Diagnosis and Management

• Reliable history of an evanescent, pruritic rash with a wheal and flare.
• Physical examination of the skin at the time symptoms are present in order to rule out other conditions is desirable, but may not be practical.
• The cause for urticaria is often idiopathic, but may be due to a drug reaction, infectious illness, or autoimmune process. Rarely it is due to a food allergy.
• Trial of second generation non-sedating antihistamines, e.g. Loratadine (Claritin) 10 mg per day (MUCH lower cost), Cetirizine (Zyrtec) 10mg per day and/or Fexofenadine (Allegra) 180mg per day, on a regular (not PRN) basis until urticaria resolves. If urticaria persists, combined antihistamine therapy with Loratadine, Cetirizine or Fexofenadine plus Atarax 25-50mg at bedtime prn is often effective. Zyrtec may be more effective for urticaria than Allegra (but may be more sedating). Cold urticaria may respond best to Cyproheptadine (Periactin) 4mg po tid.
• Avoidance of known precipitants and extremes of temperature.
• If not adequately controlled on the above antihistamines, consider adding an H2 blocker or montelukast. However, many patients will not get significant added benefit with these additional medications.
• Effective medications may need to be given regularly (daily) to suppress symptoms (such a regimen is often more satisfactory than waiting until symptoms occur).

Ongoing Management and Objectives

• Suppression of symptoms sufficient to allow for normal sleep without undue sedation during normal hours of wakefulness.
• If urticaria is chronic (more than 6-8 weeks in duration) evaluate for an underlying medical problem. Chronic hives have been associated (<50%) with such medical problems as chronic infections, rheumatologic disease, cancer, thyroid problems, etc.

Indications for Specialty Care Referral

Symptoms that cannot be adequately controlled by the regular use of antihistamines and H2 blockers.

Referral is NOT needed for acute urticaria (duration less than 6-8 weeks) since it usually resolves spontaneously.

Additional consideration may be given if there are symptoms of respiratory distress or hypotension (suggesting that anaphylaxis may be present).

Strong suggestion of an allergic component of undetermined cause.

Subspecialty consultation for urticaria and angioedema may be initially sent to either Allergy or Dermatology.

Criteria for Return to Primary Care:

Problem has resolved or a suitable management plan is in place.