What are the recommended treatments for urticaria?

Treatment of Urticaria

Second-generation H1 antihistamines are the first-line treatment for urticaria, with dose escalation up to four times the standard dose for inadequate response. 1

First-Line Treatment

• Start with standard doses of second-generation H1 antihistamines:
  • Fexofenadine 180mg daily
  • Cetirizine 10mg daily
  • Loratadine 10mg daily 1

These medications are preferred over first-generation antihistamines because they:

• Do not cross the blood-brain barrier
• Cause significantly less sedation and psychomotor impairment
• Offer more convenient dosing schedules (once or twice daily) 2

Step-wise Treatment Approach

Step 1: Standard-dose second-generation H1 antihistamine

• Begin with a standard dose of a second-generation antihistamine
• Reassess response within 1-2 weeks using validated tools like Urticaria Control Test (UCT) or Urticaria Activity Score (UAS7) 1

Step 2: Increase antihistamine dose

• If inadequate response, increase dose up to 4 times the standard dose
• This approach is effective in many patients who don't respond to standard dosing 1, 3
• Common pitfall: Many clinicians fail to increase antihistamine doses sufficiently before declaring treatment failure 1

Step 3: Add additional therapies

For patients with insufficient response to up-dosing:

• Add H2 antagonists (e.g., cimetidine, ranitidine) - particularly effective for symptomatic dermographism 1, 4
• Consider leukotriene receptor antagonists 1
• Consider higher than 4x dosing of antihistamines - shown to be effective in 49% of patients who failed 4x dosing, with minimal increase in side effects 3

Step 4: Refractory cases

For patients who fail the above approaches:

• Omalizumab
• Cyclosporine
• Other alternatives: tacrolimus, mycophenolate mofetil, dapsone, sulfasalazine, and tranexamic acid 1, 5

Special Considerations

Sedating Antihistamines

• First-generation antihistamines (e.g., diphenhydramine, hydroxyzine) should be used cautiously due to sedative effects
• May be useful for nighttime symptoms 1, 2
• Topical doxepin may provide relief but should be limited to 8 days and 10% of body surface area (maximum 12g daily) due to risk of allergic contact dermatitis 1

Anaphylaxis Management

If urticaria is accompanied by signs of anaphylaxis:

1. Administer epinephrine 0.3 mg IM in the mid-anterolateral thigh immediately
2. Seek emergency medical attention
3. Follow with combined H1+H2 blockade (diphenhydramine 25-50 mg IV plus ranitidine 50 mg IV) 1

Monitoring and Follow-up

• Reassess within 1-2 weeks of initiating or changing therapy
• Follow the principle of "as much as needed and as little as possible" for medication use
• Consider discontinuing or reducing treatment after symptom control is achieved 1

Side Effects and Safety

• Second-generation antihistamines are generally well-tolerated
• Somnolence is the most common side effect, reported in about 17% of patients
• Even at higher than 4x dosing, side effects remain limited (reported in only 10% of patients) 3
• Cardiovascular side effects with some antihistamines (terfenadine, astemizole) are rare and typically occur with overdose or drug interactions 2

Prognosis

More than half of patients with chronic urticaria will experience resolution or improvement of symptoms within a year 5. However, some cases may persist for years, requiring long-term management.