How should I manage a patient with cold urticaria who is experiencing palpitations?

Management of Cold Urticaria with Palpitations

Immediately assess for anaphylaxis and administer intramuscular epinephrine 0.3-0.5 mg (1:1000) if the patient has palpitations accompanied by any respiratory symptoms (dyspnea, wheezing, stridor), hypotension, or other systemic manifestations, as cold urticaria can progress to life-threatening anaphylaxis in up to 20% of cases. 1, 2, 3

Immediate Assessment Algorithm

When a patient with cold urticaria presents with palpitations, you must rapidly determine whether this represents:

• Anaphylaxis progression: Evaluate for tachycardia (the rule in anaphylaxis), hypotension, respiratory compromise (dyspnea, wheezing, stridor), altered mental status, or gastrointestinal symptoms (nausea, vomiting, abdominal pain) 1, 2
• Isolated cardiovascular manifestation: Palpitations alone without other systemic features may represent early anaphylaxis or anxiety-related symptoms 1

Critical distinction: Tachycardia is expected in anaphylaxis, but bradycardia may occur in patients with conduction defects, increased vagal tone, or those taking beta-blockers 1. The presence of urticaria with cardiovascular symptoms (palpitations, hypotension) strongly suggests anaphylaxis rather than a vasovagal reaction, which typically presents with bradycardia, absent urticaria, and cool/pale skin 1.

Emergency Management Protocol

If anaphylaxis is suspected (palpitations plus any other systemic symptom):

• Administer epinephrine 0.2-0.5 mL of 1:1000 (1 mg/mL) intramuscularly into the thigh immediately, repeating every 5 minutes as needed 1, 2, 4
• Position patient supine with legs elevated if hypotensive 1
• Administer 100% oxygen 1
• Establish IV access and provide aggressive fluid resuscitation (up to 50% of intravascular volume can shift to extravascular space within 10 minutes) 1
• Monitor for biphasic reactions occurring 8-12 hours after initial episode 1

Common pitfall: Patients with cold urticaria and underlying clonal mast cell disorders, those taking beta-blockers or ACE inhibitors, elderly patients, or those with significant cardiorespiratory disease are at higher risk for severe reactions and may require more aggressive treatment 1.

Non-Emergency Management

If palpitations are isolated without other systemic symptoms:

• Initiate or optimize second-generation H1 antihistamines: cetirizine 10 mg daily, fexofenadine 180 mg daily, loratadine 10 mg daily, desloratadine 5 mg daily, or levocetirizine 5 mg daily 5, 2, 4
• If inadequate response after 2-4 weeks, increase antihistamine dose up to 4 times the standard dose (over 40% of patients require higher doses for adequate control) 5
• Trial at least two different non-sedating antihistamines if the first is ineffective, as individual responses vary significantly 5

For refractory cases:

• Add H2-antihistamines (ranitidine or famotidine) for better control 5
• Consider adding leukotriene receptor antagonists (montelukast) 5

Critical Medications to Avoid

• Avoid NSAIDs and aspirin, as they inhibit cyclooxygenase and can exacerbate urticaria through leukotriene formation and histamine release 1, 5, 6
• Avoid ACE inhibitors in patients with angioedema and use with caution if angioedema is present with urticaria 1
• Avoid sedating antihistamines in elderly patients 7

Patient Education and Prevention

• Prescribe epinephrine auto-injector for all patients with cold urticaria who have experienced systemic symptoms or anaphylaxis 1, 4, 3
• Instruct patients to avoid cold exposure triggers: cold water immersion, cold air exposure, ingestion of cold substances, and administration of cold IV fluids 1, 2, 8, 3
• Warn that swimming and aquatic activities pose the highest risk for severe systemic reactions 2, 8, 4, 3
• Educate patients to inject epinephrine at the first sign of systemic symptoms rather than waiting, as adolescents and young adults are at particular risk of fatal anaphylaxis due to risk-taking behavior and failure to recognize symptoms 1

Special Considerations

Perioperative risk: Patients with cold urticaria can develop anaphylaxis from administration of cooled medications or IV fluids during surgery 1. Ensure surgical teams are aware of this diagnosis and maintain normothermia.

Desensitization: For patients with frequent unavoidable cold exposure and inadequate antihistamine response, cold desensitization protocols can lower temperature thresholds and prevent histamine release in approximately two-thirds of patients 9.