What is the recommended management of acute and chronic urticaria in children, including appropriate dosing of second‑generation antihistamines and adjunct therapies?

Management of Urticaria in Pediatric Age Group

Second-generation non-sedating H1 antihistamines are the first-line treatment for both acute and chronic urticaria in children, with dose escalation up to 4 times the standard dose recommended before adding other therapies. 1, 2

Initial Treatment Approach

Start with a second-generation antihistamine at standard dosing, offering families a choice between at least two options (cetirizine, loratadine, desloratadine, fexofenadine, or levocetirizine), as individual response and tolerance vary significantly between patients. 1, 2

• Cetirizine has the shortest time to maximum concentration, making it the preferred choice when rapid symptom relief is needed. 1, 3
• Standard pediatric dosing should be weight-adjusted according to manufacturer recommendations. 2

Dose Escalation Strategy

If symptom control is inadequate after 2-4 weeks of standard dosing, increase the antihistamine dose up to 4 times the standard dose before considering additional therapies. 1, 2, 3 This recommendation is supported by multiple guidelines, though pediatric data shows efficacy appears limited primarily to doubling the standard dose. 4

• A four-fold dose of cetirizine was necessary to significantly improve multiple urticaria parameters in one study, though doubling the dose improved pruritus alone. 1
• Approximately 67% of pediatric patients with chronic spontaneous urticaria respond to second-generation antihistamines, with most responding to standard or double doses. 4
• Tolerability of updosing is generally acceptable, with only 13.6% of children experiencing side effects, and only half of those requiring treatment change. 4

Role of Corticosteroids

Oral corticosteroids should be restricted to short courses of 3-10 days only for severe acute urticaria or angioedema involving the mouth. 1, 2, 3

• Corticosteroids can shorten the duration of acute urticaria episodes (e.g., prednisolone 50 mg daily for 3 days in adults, with lower weight-adjusted doses in children). 2, 3
• Long-term oral corticosteroids should not be used in chronic urticaria except in highly selected cases under specialist supervision, due to cumulative toxicity. 2, 5
• Corticosteroids have a slow onset of action (4-6 hours) and are not helpful for acute symptom relief. 6

Adjunctive Measures and Trigger Avoidance

Identify and minimize aggravating factors including overheating, stress, alcohol, and certain medications. 1, 2, 3

• Avoid NSAIDs in aspirin-sensitive patients with urticaria. 1, 2
• Avoid ACE inhibitors in patients with angioedema without urticaria. 2
• Cooling lotions (calamine or 1% menthol in aqueous cream) can provide additional symptomatic relief. 1, 2, 3
• Control environmental temperature through rational use of bathing, showering, swimming, and air conditioning to decrease mediator release and reduce antihistamine requirements. 1, 2, 3

When to Escalate Beyond First-Line Therapy

For chronic spontaneous urticaria (symptoms >6 weeks) unresponsive to high-dose antihistamines, omalizumab 300 mg subcutaneously every 4 weeks is the next step. 1, 2, 3

• Allow up to 6 months to evaluate response to omalizumab before considering alternative treatments. 1, 2
• Omalizumab is effective in approximately 70% of antihistamine-refractory patients. 5
• At least 30% of patients have insufficient response to omalizumab, particularly those with autoimmune urticaria mediated by IgG. 2

Cyclosporine at 4 mg/kg per day for a maximum of 2 months is recommended for patients who fail both high-dose antihistamines and omalizumab. 1, 2, 5

• Cyclosporine is effective in approximately two-thirds of patients with severe autoimmune urticaria. 1, 2
• Regular monitoring of blood pressure and renal function every 6 weeks is required due to potential side effects. 2

Emergency Management

Intramuscular epinephrine is life-saving in anaphylaxis and severe laryngeal angioedema. 1, 2, 3

• Dosing is weight-dependent: children weighing less than 25 kg should receive 0.15 mg (150 µg) via auto-injector; children over 25 kg through adults should receive 0.3 mg (300 µg). 6, 2
• When using 1:1,000 epinephrine solution, administer 0.01 mg/kg with a maximum dose of 0.5 mg. 6
• H1 antihistamines are only adjunctive therapy for relieving itching and urticaria; they do not relieve stridor, shortness of breath, wheezing, or shock, and should never be substituted for epinephrine in anaphylaxis. 6

Important Caveats

• Do not perform extensive laboratory testing for acute urticaria; testing is only indicated if symptoms persist beyond 6 weeks or if specific systemic disease is suspected. 3
• First-generation sedating antihistamines (diphenhydramine, hydroxyzine) cause sedation and cognitive impairment, and have not been proven more effective than second-generation agents. 6, 7
• H2 antihistamines and leukotriene antagonists are no longer recommended as they add little efficacy. 6, 5

Prognosis

Approximately 50% of children with chronic urticaria presenting with wheals alone will be symptom-free within 6 months. 1, 2, 3

• Patients with both wheals and angioedema have a poorer prognosis, with over 50% still having active disease after 5 years. 6, 1, 2