From the Guidelines
Urticaria treatment should begin with non-sedating antihistamines like cetirizine (10mg daily), loratadine (10mg daily), or fexofenadine (180mg daily), as they are the mainstay of therapy and have been shown to be effective in reducing symptoms 1.
Key Considerations
- For severe cases, dosages may be increased up to four times the standard dose, and adding an H2 blocker such as ranitidine (150mg twice daily) or famotidine (20mg twice daily) can help if symptoms persist 1.
- Avoiding triggers is essential, and common ones include certain foods, medications (especially NSAIDs and antibiotics), heat, cold, pressure, and stress 1.
- Chronic urticaria (lasting more than 6 weeks) may require referral to an allergist or dermatologist for additional treatments such as omalizumab or cyclosporine 1.
Treatment Options
- Non-sedating antihistamines: cetirizine, loratadine, fexofenadine
- H2 blockers: ranitidine, famotidine
- Corticosteroids: prednisone (for acute severe outbreaks)
- Immunomodulating therapies: ciclosporin, tacrolimus, mycophenolate mofetil (for severe autoimmune chronic urticaria)
Important Notes
- Urticaria occurs when mast cells in the skin release histamine and other inflammatory chemicals in response to triggers, causing blood vessels to dilate and fluid to leak into surrounding tissues, creating the characteristic wheals and itching 1.
- The duration of individual weals can be very helpful in distinguishing between different clinical patterns of urticaria, such as ordinary urticaria, physical urticarias, and urticarial vasculitis 1.
From the Research
Definition and Classification of Urticaria
- Urticaria is a common disease characterized by erythematous, edematous, itchy, and transient plaques that involve skin and mucous membranes 2
- It is classified as acute spontaneous urticaria, chronic spontaneous urticaria, chronic inducible urticaria, and episodic chronic urticaria 2
- Urticaria commonly presents with intensely pruritic wheals, sometimes with edema of the subcutaneous or interstitial tissue 3
Causes and Triggers of Urticaria
- Many factors such as infections, medicines, food, psychogenic factors, and respiratory allergens are accused of etiology, but sometimes, it is idiopathic 2
- Urticaria is caused by immunoglobulin E- and non-immunoglobulin E-mediated release of histamine and other inflammatory mediators from mast cells and basophils 3
Diagnosis of Urticaria
- Diagnosis is made clinically; anaphylaxis must be ruled out 3
- Urticarial vasculitis, drug eruptions, viral eruptions, and urticaria pigmentosa must also be considered 2
Treatment of Urticaria
- The mainstay of treatment is avoidance of triggers, if identified 3
- The first-line pharmacotherapy is second-generation H1 antihistamines, which can be titrated to greater than standard doses 3
- First-generation H1 antihistamines, H2 antihistamines, leukotriene receptor antagonists, high-potency antihistamines, and brief corticosteroid bursts may be used as adjunctive treatment 3
- The addition of a prednisone burst improves the symptomatic and clinical response of acute urticaria to antihistamines 4, but another study found that the addition of prednisone did not improve the symptomatic and clinical response of acute urticaria to levocetirizine 5
Treatment of Chronic Urticaria
- In refractory chronic urticaria, patients can be referred to subspecialists for additional treatments, such as omalizumab or cyclosporine 3
- Steroid-sparing agents such as azathioprine may be used for treatment of recalcitrant itch in urticarial dermatitis 6
- More than one-half of patients with chronic urticaria will have resolution or improvement of symptoms within a year 3