Hives from medication
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Hives from Medication: Causes, Symptoms, and Treatments
Introduction to Medication-Induced Hives
Hives, also known as urticaria, are raised, itchy welts on the skin that can result from various triggers, including medications. Medication-induced hives are a common allergic reaction that can range from mild to severe, sometimes accompanied by other symptoms such as swelling (angioedema), dizziness, and vomiting 1.
Common Medications Causing Hives
Analgesics and NSAIDs
Analgesics like acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are frequent culprits in medication-induced hives. A case study highlighted a 31-year-old woman who developed hives and other symptoms such as facial swelling and dizziness after taking acetaminophen and aspirin 1. This reaction underscores the potential for common pain relievers to trigger significant allergic responses.
Antihistamines and Other Treatments
While antihistamines are typically used to treat hives, some patients may still experience symptoms despite their use. For instance, the same patient continued to have breakthrough hives even while taking loratadine and cetirizine 1. This suggests that while antihistamines can be effective, they may not always fully control symptoms in all patients.
Efficacy of Antihistamines in Treating Chronic Urticaria
Terfenadine vs. Chlorpheniramine
A study comparing the efficacy of terfenadine, a nonsedating H1 antihistamine, with chlorpheniramine and placebo found that terfenadine significantly improved symptoms of chronic idiopathic urticaria, including pruritus and redness, more effectively than chlorpheniramine and placebo 2. This indicates that nonsedating antihistamines may offer superior symptom control with fewer side effects like drowsiness.
Loratadine for Urticaria
Loratadine, another nonsedating antihistamine, is available over-the-counter for the relief of itching due to hives. However, it is important to note that while loratadine can treat hives, it does not prevent them from occurring 3. Patients are advised to avoid known triggers and seek medical attention if severe symptoms like difficulty breathing or swallowing occur 3.
Alternative Treatments for Refractory Cases
Nifedipine
For patients with chronic urticaria that does not respond to antihistamines, nifedipine, a calcium channel blocker, has shown promise. A double-blind, placebo-controlled trial demonstrated that nifedipine significantly reduced hive count and itch index in patients with chronic idiopathic urticaria 4. This suggests that nifedipine can be an effective adjunct therapy for difficult-to-treat cases.
Azathioprine
In cases of autoimmune urticaria, where traditional treatments may fail, immunosuppressive agents like azathioprine can be beneficial. A study found that azathioprine significantly reduced the severity of urticaria and the need for rescue antihistamines in patients with chronic urticaria 6. This highlights the potential of azathioprine as a cost-effective treatment option with lasting therapeutic effects.
Conclusion
Medication-induced hives are a common and sometimes severe allergic reaction. While antihistamines like terfenadine and loratadine are effective for many patients, alternative treatments such as nifedipine and azathioprine may be necessary for refractory cases. Patients experiencing severe symptoms should seek immediate medical attention, and those with chronic urticaria should work closely with their healthcare providers to identify the most effective treatment plan.
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Most relevant research papers on this topic
An unusual case of immediate hypersensitivity reaction to a common medication.
A rare case of immediate hypersensitivity to a common medication, aspirin, acetaminophen, and caffeine, led to coalescing hives, swelling, dizziness, and vomiting within 1 hour of taking the medication.
Case ReportDouble-blind comparison of terfenadine, chlorpheniramine, and placebo in the treatment of chronic idiopathic urticaria.
Terfenadine provides superior symptom control and less drowsiness and fatigue compared to chlorpheniramine for primary management of chronic idiopathic urticaria.
RCTOTC product: Loratadine for urticaria.
Claritin Non-Drowsy Hives Relief effectively relieves itching caused by hives, making it a safe and effective OTC treatment for urticaria.
Therapy of chronic idiopathic urticaria with nifedipine: demonstration of beneficial effect in a double-blinded, placebo-controlled, crossover trial.
Nifedipine, when used as an adjunct to antihistamines, is a safe and effective treatment for chronic idiopathic urticaria.
RCTUrticaria and angioedema.
Urticaria and angioedema are common but often not due to allergy, and stress is a major contributor to both conditions.
Azathioprine in autologous serum skin test positive chronic urticaria: A case–control study in a tertiary care hospital of eastern India
Azathioprine effectively reduces the intensity of chronic urticaria and reduces the need for rescue antihistamines, with minimal hematological or biochemical disturbances.
RCTUrticaria and angioedema
Urticaria and angioedema are common disorders, and managing them effectively requires understanding their causes, diagnosis, and treatment strategies.
Highly CitedRecall Urticaria: Aspirin Also Induces It.
Recall urticaria can be caused by NSAIDs, such as ibuprofen, in patients with previous subcutaneous allergen immunotherapy.
Case ReportUrticaria. The diagnostic challenge of hives.
Hives are a diagnostic challenge, and treatment varies depending on the severity and duration of symptoms.
Diagnosis and treatment of urticaria in primary care
Urticaria is a common condition caused by factors such as infections, medicines, food, psychogenic factors, and respiratory allergens, and can be effectively treated with H1 antihistamines and short-term systemic corticosteroids.
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