Clinical Guidelines
The American Academy of Allergy, Asthma, and Immunology (AAAAI) and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA2LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO) have both updated their guidelines for managing chronic urticaria. [47] While some differences in their recommendations exist, the core recommendations remain similar.
A brief summary and highlights of the AAAAI guidelines are as follows:
-
Second-generation nonsedating H 1 antihistamines as first-line treatment
-
First-generation H 1 antihistamines remain in the treatment algorithm (differs from EAACI/GA 2LEN/EDF/WAO guidelines)
-
Equally weighted second-line options to consider: Up-dosing second-generation H 1 antihistamines; adding other second-generation H 1 antihistamines; adding H 2 antagonists, leukotriene receptor antagonists, or first-generation H 1 antihistamines at bedtime
-
Third-line treatment option is omalizumab
-
Corticosteroids considered only for the short-term intervention; avoid as long-term treatment
-
Acknowledged role for cyclosporine A as add-on for refractory chronic urticaria not responsive to other treatments
A brief summary and highlights of EAACI/GA2LEN/EDF/WAO guidelines are as follows:
-
First-line treatment is second-generation H 1 antihistamines
-
Second-line therapy is up-dosing second-generation H 1 antihistamines
-
Third-line treatment is omalizumab, which is recommended before the more toxic cyclosporine A
-
H 2 antihistamines not included in algorithm (used only on an individual case basis but not as first-, second-, or third-line treatment)
-
Avoid first-generation H 1 antihistamines based on benefit-to-risk ratio
-
Corticosteroids considered only for the short-term intervention; avoid as long-term treatment
-
Acknowledged role for cyclosporine A as add-on for refractory chronic urticaria not responsive to other treatments
In March 2015, the Standards of Care Committee of the British Society for Allergy and Clinical Immunology published guidelines on treatment of chronic urticaria. [48] Management must include the identification and exclusion of possible triggers, patient education, and a personalized management plan.
Often, food allergy can be excluded as a cause of urticaria if no temporal relationship exists to a particular food trigger, by either ingestion or contact. Food additives rarely cause chronic urticaria. Certain drugs may cause or aggravate chronic urticaria; therefore, a detailed drug history is mandatory.
Up to 50% of chronic urticaria cases in older children and adults are reported to be autoimmune in nature, and these may be associated with other autoimmune conditions such as thyroiditis. Autoimmune and some inducible wheals can follow a more protracted course and may be more resistant to treatment.
Antihistamine doses at higher than normal levels may be required to control severe urticaria. An increased dose of a single antihistamine is preferred over mixing different antihistamines.
For adult patients with wheals, check that symptomatic episodes have not followed ingestion of an NSAID (eg, aspirin, ibuprofen). Provide an explanation for the symptoms and reassure that the histamine-induced chronic urticaria symptoms do not involve the respiratory tract or cardiovascular system, such as occurs in anaphylaxis. Note that very rare exceptions to this rule do exist. A once-daily dose of a long-acting, nonsedating antihistamine should be given, as necessary, if symptoms are infrequent. If necessary, double the antihistamine dose (usually given at night), and/or add a second antihistamine. Consider (1) further increases of antihistamine doses (≤ 4 times recommended), (2) adding one or more second-line drugs, and/or (3) short-term oral corticosteroid rescue treatment.
For chronic urticaria in children, the primary strategy should be avoidance of known provoking stimuli. The mainstay of treatment for children with chronic urticaria is nonsedating antihistamines; up to 4 times the recommended dose may be required for adequate symptom control. In patients who do not respond to high-dose antihistamine therapy, consider the possibility of an underlying diagnosis such as vasculitis.
For chronic urticaria in pregnancy and breastfeeding, antihistamine treatment can possibly be reduced, as chronic urticaria often improves in pregnancy. Note, however, that in some rare cases it deteriorates. While the risks of prenatal urticaria treatment are small, pregnant women should be informed that no drug can be considered absolutely safe. Antihistamines should only be used if clearly needed. If an antihistamine is required in pregnancy, the lowest dose of chlorphenamine, cetirizine, or loratadine should be used. In breastfeeding mothers, either cetirizine or loratadine at the lowest effective does is recommended and chlorphenamine should be avoided.
-
Urticaria developed after bites from an imported fire ant.
-
Urticaria associated with a drug reaction.
