Management of Urticaria in Children
Non-sedating second-generation H1 antihistamines at standard doses are the first-line treatment for all types of urticaria in children, with dose escalation up to 2-4 times the standard dose if symptoms are not controlled within 2-4 weeks. 1
First-Line Treatment: Non-Sedating H1 Antihistamines
Standard Dosing
- Begin with weight-adjusted standard doses of second-generation non-sedating H1 antihistamines 1
- Available options include cetirizine, desloratadine, fexofenadine, levocetirizine, loratadine, and mizolastine (all once daily) 1
- Offer patients a choice of at least two different antihistamines, as individual responses and tolerance vary significantly 1
- Continue standard dosing for 2-4 weeks before considering dose escalation 2
Key Antihistamine Characteristics
- Cetirizine has the shortest time to maximum concentration, advantageous when rapid symptom control is needed, though it may be sedating at higher doses 1
- Desloratadine has the longest elimination half-life (27 hours) and should be discontinued 6 days before skin prick testing 1
- First-generation sedating antihistamines are no longer recommended as monotherapy due to concerns about reduced concentration and performance 1
Dose Escalation Strategy
When to Escalate
- If urticaria is not controlled after 2-4 weeks of standard dosing, increase the antihistamine dose 1, 2
- Frequency of rash >4 days per week predicts failure of standard dosing and need for escalation 3
Updosing Protocol
- In children, increase doses up to 2-fold the standard dose as the primary escalation strategy 4, 5
- While adult guidelines recommend up to 4-fold dosing 6, 1, pediatric evidence shows efficacy is primarily limited to double the standard dose 4
- In one pediatric study, 66.7% of children responded to antihistamines: 25 with standard dose, 16 with double dose, only 2 with triple dose, and 1 with fourfold dose 4
- Updosing is generally well-tolerated, with only 13.6% experiencing side effects, and only 4.5% requiring treatment change 4
Important caveat: The evidence for higher than 2-fold dosing in children is limited, though it has become common practice when potential benefits outweigh risks 1
Treatment of Acute Severe Itching
Acute Urticaria Management
- For acute urticaria (lasting <6 weeks), second-generation H1 antihistamines remain first-line 7, 8
- Short courses of oral corticosteroids may be added if there is minimal or no response to antihistamines 7
- Long-term corticosteroids are not recommended 7
Adjunctive Measures for Severe Itching
- Cooling antipruritic lotions such as calamine or 1% menthol in aqueous cream provide symptomatic relief 1
- A sedating antihistamine at night (e.g., chlorphenamine 4-12 mg, hydroxyzine 10-50 mg) may be added to help sleep, though it adds little additional effect on urticaria control if H1 receptors are already saturated 1
- Addition of H2 antihistamines may sometimes provide better control than H1 antihistamines alone, though this is more helpful for accompanying dyspepsia 1
Chronic Urticaria Management
Definition and Natural History
- Chronic urticaria is defined as continuous activity for ≥6 weeks 1
- Children with chronic urticaria generally respond better to H1 antihistamines compared to adults 9
- High resolution rate within two years in pediatric populations 9
Stepped Treatment Algorithm
Step 1: Standard-dose second-generation H1 antihistamine for 2-4 weeks 1, 2
Step 2: Increase antihistamine dose up to 2-fold (up to 4-fold based on adult data, though pediatric efficacy limited beyond 2-fold) 6, 1, 4
Step 3: For antihistamine-refractory cases, omalizumab is the second-line treatment with excellent efficacy in children 6, 9
- Start with 300 mg every 4 weeks 6
- Allow up to 6 months for response 6
- If insufficient response, consider updosing by shortening intervals and/or increasing dosage (maximum 600 mg every 14 days) 6
Step 4: Cyclosporine is third-line for patients who do not respond to omalizumab 6
- Monitor blood pressure and renal function due to risks of hypertension and renal failure 6
- Also carries risks of epilepsy in predisposed patients, hirsutism, and gum hypertrophy 6
Alternative Agents
- Dupilumab has emerged as a potential treatment option and is approved for chronic spontaneous urticaria in some countries 9
- Leukotriene receptor antagonists may be considered if minimal response to antihistamines, though evidence is conflicting 2, 7
Non-Pharmacologic Management
Trigger Avoidance
- Minimize nonspecific aggravating factors: overheating, stress, alcohol 1
- Avoid aspirin and NSAIDs in all urticaria patients, as they can worsen symptoms through cyclooxygenase inhibition 1
- Avoid ACE inhibitors in patients with angioedema without wheals, and use with caution if angioedema is present with urticaria 1
- Prevent skin drying, avoid hot showers, scrubbing, and excessive sun exposure 2
Patient Education
- Explain that a specific cause is unlikely to be found in most cases 1
- Reassure that prognosis for eventual recovery from ordinary, physical, and vasculitic urticarias is excellent 1
- Provide written information materials 1
Diagnostic Considerations
When to Investigate
- Routine laboratory investigation is not cost-effective in chronic spontaneous urticaria unless clinical features suggest autoimmune disease 2
- For chronic cases not responsive to antihistamines, consider basic tests: differential blood count, C-reactive protein/ESR, total IgE, and IgG-anti-thyroid peroxidase 6
- High ratio of IgG-anti-TPO to total IgE is the best surrogate marker for autoimmune chronic spontaneous urticaria 6
Special Populations
- Pregnancy: Avoid all antihistamines if possible, especially first trimester; chlorphenamine often chosen due to long safety record 1
- Renal impairment: Halve dose of cetirizine, levocetirizine, and hydroxyzine; avoid acrivastine in moderate impairment 1
- Hepatic impairment: Avoid mizolastine, alimemazine, chlorphenamine, and hydroxyzine in severe disease 1