Less-sedating antihistamines
Monotherapy with a less-sedating antihistamine is first-line treatment of urticaria in adults and children. Less-sedating antihistamines have similar efficacy as (and are better tolerated than) sedating antihistamines. Sedating antihistamines should only be used in patients with disturbed sleep related to urticaria (see Sleep disturbance associated with urticaria).
For first-line therapy of urticaria in an adult or child 12 years and older, use:
1cetirizine 10 mg orally, once daily1 cetirizine cetirizine cetirizine
OR
1desloratadine 5 mg orally, once daily desloratadine desloratadine desloratadine
OR
1fexofenadine 180 mg orally, once daily fexofenadine fexofenadine fexofenadine
OR
1loratadine 10 mg orally, once daily. loratadine loratadine loratadine
For first-line therapy of urticaria in a child younger than 12 years, use:
1cetirizine1 cetirizine cetirizine cetirizine
child 1 to 2 years: 0.25 mg/kg (up to 2.5 mg) orally, twice daily
child 2 to 6 years: 5 mg orally, once daily or in 2 divided doses
child 6 to 12 years: 10 mg orally, once daily or in 2 divided doses
OR
1desloratadine desloratadine desloratadine desloratadine
child 6 to 12 months: 1 mg orally, once daily
child 1 to 6 years: 1.25 mg orally, once daily
child 6 to 12 years: 2.5 mg orally, once daily
OR
1fexofenadine fexofenadine fexofenadine fexofenadine
child 6 months to 2 years: 15 mg orally, twice daily
child 2 to 12 years: 30 mg orally, twice daily
OR
1loratadine loratadine loratadine loratadine
child 1 to 2 years: 2.5 mg orally, once daily
child 2 to 12 years and weight less than 30 kg: 5 mg orally, once daily
child 2 years or older and weight more than 30 kg: 10 mg orally, once daily.
Less-sedating antihistamines are typically given in the morning, but they can be given at night if night-time symptoms are an issue.
Adults and children older than 12 years may need another dose late in the afternoon, because urticaria often flares early in the evening.
Response and tolerance of a less-sedating antihistamine varies between patients. If therapy with one less-sedating antihistamine is not effective or causes drowsiness during the day, change to a different less-sedating antihistamine. Sedating potential of less-sedating antihistamines can vary between patients; of the less-sedating antihistamines, cetirizine is the most likely to cause sedation.
If symptoms persist, trial higher doses of the less-sedating antihistamine (eg increasing doses over 2 to 4 weeks)—up to four times the standard recommended dosage (in two divided doses) is safe and effective in adults, but this has not been confirmed in young children. Parents or carers may be concerned about long-term safety with higher doses in children. Higher doses of cetirizine can be safely taken in children older than 6 months The Royal Children's Hospital (RCH), 2019. However, if long-term therapy is required, consider specialist referral and assessment for other treatment options (eg omalizumab).
If there is good response, continue treatment until urticaria is well controlled, reassess symptoms and consider weaning over a few months (because abrupt withdrawal can cause symptoms to recur). If symptoms recur during weaning, restart therapy (control of symptoms often takes a couple of weeks) and consider specialist referral.