Management of Urticaria on Hands and Legs
Start immediately with a second-generation non-sedating H1 antihistamine (cetirizine 10 mg, fexofenadine 180 mg, loratadine 10 mg, or desloratadine 5 mg daily) and if symptoms persist after 2-4 weeks, increase the dose up to 4 times the standard dose. 1, 2
Initial Clinical Assessment
First, determine the duration and pattern of the urticaria to guide your diagnostic and therapeutic approach:
Ask how long each individual wheal lasts: Typical urticaria wheals last 2-24 hours, while physical urticaria resolves within 1 hour 3, 4. If individual lesions persist beyond 24 hours, suspect urticarial vasculitis and obtain a skin biopsy 3, 4.
Classify as acute versus chronic: Acute urticaria lasts less than 6 weeks, while chronic urticaria persists for 6 weeks or more 3, 5.
Identify potential triggers: Ask specifically about recent medications (especially NSAIDs, aspirin, ACE inhibitors, codeine), foods, infections, physical stimuli (pressure, heat, cold, exercise), and whether the patient can reproducibly trigger the wheals 3.
First-Line Pharmacologic Treatment
Begin with a single second-generation H1 antihistamine at standard dosing for 2-4 weeks 1, 2, 4:
- Cetirizine 10 mg daily
- Fexofenadine 180 mg daily
- Loratadine 10 mg daily
- Desloratadine 5 mg daily
- Levocetirizine 5 mg daily
Critical point: Trial at least two different non-sedating antihistamines if the first is ineffective, as individual responses vary significantly 1, 2, 4.
Dose Escalation for Inadequate Response
If standard dosing provides inadequate control after 2-4 weeks, increase the antihistamine dose up to 4 times the standard dose 1, 2, 4. Over 40% of patients with ordinary urticaria respond to antihistamines alone, but many require higher doses 1.
Adjunctive Therapies for Resistant Cases
When high-dose second-generation antihistamines are insufficient:
Add a first-generation antihistamine at night (chlorphenamine 4-12 mg or hydroxyzine 10-50 mg) to help with sleep and provide additional symptom control 2, 4.
Consider adding an H2-antihistamine (ranitidine or famotidine), which may provide better control than H1 antihistamines alone 1, 2.
Add a leukotriene receptor antagonist (montelukast) for refractory cases, particularly beneficial for aspirin-sensitive urticaria 1, 4.
Critical Medications and Triggers to Avoid
Avoid NSAIDs and aspirin completely, as they inhibit cyclooxygenase and can exacerbate urticaria through leukotriene formation and histamine release 1, 2, 4. Cross-reactions between aspirin and other NSAIDs are common 2.
Discontinue ACE inhibitors immediately if angioedema is present, as they cause angioedema through inhibition of kinin breakdown 2, 4.
Role of Corticosteroids
Restrict oral corticosteroids to short courses only for severe acute episodes, due to cumulative toxicity including hypertension, hyperglycemia, osteoporosis, and gastric complications 1, 2, 4. They should not be used for maintenance treatment 2.
Advanced Therapies for Chronic Refractory Urticaria
If symptoms persist despite high-dose antihistamines and adjunctive therapies:
Omalizumab 300 mg subcutaneously every 4 weeks is recommended for chronic spontaneous urticaria unresponsive to high-dose antihistamines 2, 4.
Cyclosporine 4 mg/kg daily for up to 2 months is effective in approximately 65-70% of patients with severe autoimmune urticaria who fail omalizumab 4, 6.
Emergency Management
Administer intramuscular epinephrine 0.5 mL of 1:1000 immediately if systemic symptoms develop, including wheezing, hypotension, laryngeal edema, oxygen desaturation, or cardiovascular collapse 1, 4.
Common Pitfalls to Avoid
- Inadequate antihistamine dosing: Many patients require higher than standard doses for adequate control 2.
- Continuing NSAIDs in aspirin-sensitive patients: All NSAIDs should be avoided in these patients 2.
- Prolonged corticosteroid use: Should be restricted to short courses to avoid cumulative toxicity 1, 2.
- Extensive laboratory testing: Only perform limited workup unless history or physical examination suggests specific underlying conditions 5, 7.
Prognosis
About 50% of patients with chronic urticaria presenting with wheals alone will be clear by 6 months 1, 2, 4. However, patients with both wheals and angioedema have a poorer outlook, with over 50% still having active disease after 5 years 4.