From the Guidelines
The treatment for acute severe urticaria primarily involves antihistamines, with second-generation H1 antihistamines being the first-line therapy, as recommended by the most recent guidelines 1.
First-Line Therapy
- Start with medications like cetirizine 10mg, loratadine 10mg, or fexofenadine 180mg daily.
- For severe cases, dosing can be increased up to four times the standard dose, as supported by the British Journal of Dermatology guidelines 1.
Additional Therapy
- If symptoms persist, add an H2 antihistamine such as famotidine 20mg twice daily or ranitidine 150mg twice daily.
- For breakthrough or severe symptoms, a short course of oral corticosteroids like prednisone 40-60mg daily for 3-5 days can provide relief, as suggested by the guidelines for evaluation and management of urticaria in adults and children 1.
Emergency Situations
- In emergency situations with angioedema or respiratory involvement, epinephrine (0.3-0.5mg intramuscularly) may be necessary, as emphasized by the 2020 practice parameter update on anaphylaxis 1.
Symptomatic Relief
- Patients should avoid known triggers, wear loose clothing, and use cool compresses for symptomatic relief.
- Antihistamines work by blocking histamine receptors, preventing mast cell mediators from causing the characteristic wheals, itching, and swelling.
- Corticosteroids reduce inflammation by suppressing multiple inflammatory pathways.
- Most acute urticaria episodes resolve within 24-48 hours with appropriate treatment, though some patients may require medication for up to two weeks.
From the FDA Drug Label
The initial suppressive dose level should be continued until satisfactory clinical response is obtained, usually four to ten days in the case of many allergic and collagen diseases. In less severe disease processes in which corticoid therapy is indicated, it may be possible to initiate treatment with alternate day therapy. More severe disease states usually will require daily divided high dose therapy for initial control of the disease process The treatment for acute severe urticaria may involve daily divided high dose of prednisone for initial control of the disease process, which can be continued for 4 to 10 days until a satisfactory clinical response is obtained 2.
- The dose may need to be reduced to the lowest effective level as rapidly as possible after control has been established.
- Alternate day therapy may be considered after initial control, but it may not be suitable for all patients.
From the Research
Treatment Options for Acute Severe Urticaria
- Antihistamines are the mainstay of treatment for urticaria, including acute severe urticaria 3, 4, 5
- Second-generation antihistamines, such as cetirizine, loratadine, and mizolastine, are preferred due to their reduced sedative and anticholinergic effects 3, 4
- Intravenous cetirizine has been shown to be effective in treating acute urticaria, with benefits of less sedation, fewer adverse events, and shorter time spent in treatment center 4
Comparison of Treatment Options
- A systematic review of 10 randomized controlled trials found that the addition of corticosteroids to antihistamines did not improve symptoms of acute urticaria in most cases 6
- The combination of diphenhydramine and ranitidine or cimetidine was found to be effective in relieving urticaria symptoms in some studies 6
- A study comparing levocetirizine 10 mg to a combination of levocetirizine 5 mg and montelukast 10 mg found that both treatments were effective in reducing urticaria symptoms, but the combination treatment had fewer adverse effects and improved quality of life 7
Key Considerations
- The choice of treatment for acute severe urticaria should be based on the individual patient's needs and medical history 5
- Further research is needed to establish evidence-based treatment guidelines for acute urticaria, particularly regarding the use of corticosteroids and other adjunctive treatments 6