What is the initial treatment for a patient with hives?

Initial Treatment for Hives

Start immediately with a second-generation non-sedating H1 antihistamine such as cetirizine 10 mg once daily or loratadine 10 mg once daily, and if symptoms persist after 2-4 weeks, increase the dose up to 4 times the standard dose. 1, 2

First-Line Therapy: Non-Sedating Antihistamines

• Offer the patient a choice between at least two different second-generation antihistamines (cetirizine, loratadine, desloratadine, fexofenadine, or levocetirizine), as individual responses and tolerance vary significantly between agents 1, 3, 2

• Cetirizine has the shortest time to maximum concentration, making it the preferred choice when rapid symptom relief is the priority 1, 3

• Avoid first-generation antihistamines (diphenhydramine, hydroxyzine, chlorpheniramine) as primary therapy due to significant sedation and anticholinergic effects, though they may be added at bedtime for additional symptom control if needed 2

Dose Escalation Algorithm

• If standard dosing provides inadequate control within 24-48 hours for acute urticaria or 2-4 weeks for chronic urticaria, increase the antihistamine dose up to 4 times the standard dose 4, 1, 2

• This updosing strategy (e.g., cetirizine 40 mg daily or loratadine 40 mg daily) is recommended when potential benefits outweigh risks 4, 2

Adjunctive Measures for Immediate Management

• For severe acute urticaria with inadequate antihistamine response, add a short course of oral corticosteroids (e.g., prednisolone 50 mg daily for 3-10 days maximum) 1, 3

• Restrict corticosteroids to short courses only for severe acute exacerbations; long-term use should be avoided due to cumulative toxicity 3, 2

• Prescribe an epinephrine autoinjector if there is any concern for potential anaphylaxis or severe angioedema involving the airway, particularly if hives occur with organ involvement (respiratory, cardiovascular, or neurologic symptoms) 4, 1

Trigger Identification and Avoidance

• Identify and minimize aggravating factors including overheating, stress, alcohol, aspirin, NSAIDs, and codeine 1, 3

• Apply cooling antipruritic lotions (calamine or 1% menthol in aqueous cream) for symptomatic relief 1

• Control environmental temperature through rational use of bathing, showering, swimming, and air conditioning to decrease mediator release 1

Critical Distinction: When to Use Epinephrine vs. Antihistamines Alone

• Use antihistamines alone for isolated hives with mild itching and no systemic symptoms 4, 1

• Use epinephrine immediately for systemic hives with organ involvement: upper/lower airway symptoms, gastrointestinal symptoms, neurologic changes, cardiovascular compromise, hypotension, laryngeal edema, oxygen desaturation, or seizures 4

• When uncertain whether symptoms represent anaphylaxis, err on the side of prompt epinephrine injection rather than relying solely on antihistamines 4

When Symptoms Persist Beyond 6 Weeks

• If symptoms persist beyond 6 weeks despite high-dose antihistamines, the patient has chronic spontaneous urticaria and should be referred to an allergist or dermatologist 1, 3

• Second-line therapy is omalizumab 300 mg subcutaneously every 4 weeks, with up to 6 months allowed for response 4, 1, 3

• Third-line therapy is cyclosporine 4 mg/kg daily for up to 2 months, reserved for specialist management in patients who fail omalizumab 4, 1, 2

Important Caveats

• Do not perform extensive laboratory testing for acute urticaria; testing is only indicated if symptoms persist beyond 6 weeks or if specific systemic disease is suspected 1, 2

• Approximately 50% of patients with chronic urticaria presenting with only hives will be clear by 6 months, though those with both hives and angioedema have a poorer prognosis with over 50% still having active disease after 5 years 4, 3

• Adjust antihistamine dosing in renal impairment: halve the dose of cetirizine and levocetirizine in moderate renal impairment, and avoid these agents entirely in severe renal impairment 3, 2