Treatment of Urticaria in Pediatric Patients

Introduction to Urticaria Management

• The American Academy of Pediatrics recommends non-sedating H1 antihistamines as the first-line treatment for pediatric urticaria, with the possibility of increasing the dose up to 4 times the standard dose if symptom control is inadequate 1, 2
• The British Association of Dermatologists suggests starting with non-sedating antihistamines such as cetirizine, desloratadina, fexofenadine, levocetirizina, loratadina, or mizolastina at standard doses 3, 1, 2

Therapeutic Approach

• Offer the patient a choice between at least two different antihistamines, as response and tolerance vary significantly between individuals 1, 4, 2
• Cetirizine has the shortest time to reach maximum concentration, advantageous for rapid relief 4
• If symptom control is inadequate after 2-4 weeks, increase the dose up to 4 times the standard dose before considering additional therapies 1, 4, 2

Second-Line Therapy: Omalizumab

• For chronic spontaneous urticaria unresponsive to high-dose antihistamines, consider omalizumab (anti-IgE monoclonal antibody) at a dose of 300 mg every 4 weeks 1, 4, 2
• Wait up to 6 months to evaluate the response to omalizumab before considering alternative treatments 1, 4, 2
• At least 30% of patients have an insufficient response to omalizumab, particularly those with autoimmune urticaria mediated by IgG 4

Third-Line Therapy: Cyclosporine

• Cyclosporine is recommended for patients who do not respond to high-dose antihistamines and omalizumab, at a dose of 4 mg/kg per day for a maximum of 2 months 1, 2
• It is effective in approximately two-thirds of patients with severe autoimmune urticaria 3
• Regular monitoring of blood pressure and renal function (every 6 weeks) is required due to potential side effects 1, 2

Role of Corticosteroids

• Oral corticosteroids can shorten the duration of acute urticaria (e.g., prednisolone 50 mg per day for 3 days in adults, lower doses in children) 3
• Limit corticosteroids to short courses (3-10 days) only for severe acute exacerbations or angioedema involving the mouth 2
• Long-term oral corticosteroids should not be used in chronic urticaria except in highly selected cases under specialist supervision 3

Emergency Management

• Intramuscular epinephrine is life-saving in anaphylaxis and severe laryngeal angioedema 3, 5
• The dosage is weight-dependent: 0.5 mL of 1:1000 (500 µg) for adults and adolescents over 12 years; auto-injector pens 300 µg for adults or 150 µg for children between 15 and 30 kg 3
• If there is no significant relief of symptoms after the first dose of epinephrine, administer an additional dose 3

Special Population Considerations

Renal Insufficiency

• Avoid acrivastine in moderate renal insufficiency (creatinine clearance 10-20 mL/min) 3, 1, 4
• Halve the dose of cetirizine, levocetirizine, and hydroxyzine in moderate renal insufficiency 3, 1
• Avoid cetirizine, levocetirizine, and alimemazine in severe renal insufficiency (creatinine clearance < 10 mL/min) 3

Hepatic Insufficiency

• Avoid mizolastine in significant hepatic insufficiency 3, 1, 4, 2
• Avoid alimemazine, chlorphenamine, and hydroxyzine in severe hepatic insufficiency 3, 4

Pregnancy

• It is best to avoid all antihistamines in pregnancy, especially during the first trimester 3, 1, 2
• If antihistamine therapy is necessary, choose chlorphenamine for its long record of safety 3, 1, 2
• Loratadine and cetirizine are FDA Category B drugs for pregnancy 3, 1
• Hydroxyzine is specifically contraindicated during the early stages of pregnancy 3, 2

General Measures and Prevention

• Identify and minimize aggravating factors such as overheating, stress, alcohol, and certain medications (aspirin, NSAIDs, codeine) 1, 4, 2
• Avoid NSAIDs in patients sensitive to aspirin with urticaria 1, 2
• Avoid ACE inhibitors in patients with angioedema without urticaria 1, 2
• Cooling lotions (calamine or 1% menthol in aqueous cream) can provide symptomatic relief 1
• Controlling temperature within reasonable limits can reduce symptoms in children; rational use of bathing, showering, swimming, and air conditioning can decrease mediator symptoms and the need for antihistamines 5

Prognosis

• Approximately 50% of patients with chronic urticaria who present with only hives will be symptom-free within 6 months 4, 2
• Patients with hives and angioedema have a poorer prognosis, with over 50% still presenting active disease after 5 years 4, 2

Evidence‑Based Management of Pediatric Urticaria

Pharmacologic Therapy

• Corticosteroids have a delayed onset of action (approximately 4–6 hours) and therefore do not provide rapid relief of acute urticaria symptoms. 6
• First‑generation (sedating) antihistamines such as diphenhydramine and hydroxyzine cause sedation and cognitive impairment and have not demonstrated superior efficacy compared with second‑generation agents. 6, 7
• H₂‑antihistamines and leukotriene‑receptor antagonists are no longer recommended for urticaria because they add little clinical benefit. 6

Emergency Management

• Intramuscular epinephrine is the life‑saving treatment for anaphylaxis and severe laryngeal angio‑edema. Weight‑based dosing:
  
  • Children < 25 kg – 0.15 mg (150 µg) via auto‑injector.
  • Children ≥ 25 kg – 0.3 mg (300 µg) via auto‑injector.
  • When using a 1:1,000 solution, give 0.01 mg/kg with a maximum of 0.5 mg. Both dosing recommendations are supported by the same evidence. 7
• H₁‑antihistamines are only adjunctive agents for relieving itching and cutaneous wheals; they do not alleviate stridor, dyspnea, wheezing, or circulatory shock and should never replace epinephrine in anaphylaxis. 6, 7

Prognosis

• Children who present with both wheals and angio‑edema have a poorer long‑term outlook, with more than 50 % remaining symptomatic after five years. 8