In a healthy adult with a pruritic abdominal rash that occurs mainly in cold weather, what is the most likely etiology and appropriate initial management?

Cold-Induced Abdominal Pruritus: Cold Urticaria

You most likely have cold urticaria, a form of physical urticaria triggered by cold exposure that causes itchy wheals (hives) or pruritus without visible rash, and should be treated with non-sedating antihistamines as first-line therapy while strictly avoiding cold triggers. 1, 2, 3

Understanding Your Condition

Cold urticaria occurs when cold exposure triggers mast cell activation and release of histamine and other inflammatory mediators, causing itchy skin reactions. 2, 3 The abdomen is a common site because:

• It has thinner clothing coverage during temperature changes 1
• Direct cold contact (cold air, cold surfaces) triggers symptoms within minutes 2, 4
• Symptoms typically appear as itchy wheals (raised bumps) but can present as pruritus alone in milder cases 1, 3

Diagnostic Confirmation

Ice cube test: Apply an ice cube wrapped in plastic to your forearm for 5 minutes, then observe for 10-15 minutes after removal. 1, 2 A positive test shows:

• Development of wheals or intense itching at the contact site 1, 4
• Symptoms appearing within 2-10 minutes after cold removal 2, 4

If the ice cube test is negative but symptoms persist with cold exposure, consider atypical cold urticaria forms that require specialized testing. 2, 4

Immediate Management Strategy

First-Line Treatment

Non-sedating antihistamines are the cornerstone of therapy: 2, 3, 4

• Fexofenadine 180 mg daily (preferred) 5
• Loratadine 10 mg daily as alternative 5, 6
• Cetirizine 10 mg daily as alternative 7, 5

These medications work by blocking histamine release and reducing itch intensity. 2, 3

Cold Avoidance (Essential)

• Wear layered clothing covering the abdomen during cold weather 2, 3
• Avoid sudden temperature changes (cold showers, swimming in cold water) 3, 4
• Pre-medicate with antihistamines 1-2 hours before unavoidable cold exposure 2, 3

Symptomatic Relief

• Apply high-lipid content emollients twice daily to reduce skin barrier dysfunction 5, 6
• Keep the abdomen covered with warm, breathable cotton clothing 8

When Antihistamines Fail

If symptoms persist after 2-4 weeks of standard-dose antihistamines: 2, 3

1. Increase antihistamine dose up to 4-fold (e.g., fexofenadine 180 mg twice daily) 2, 3
2. Add omalizumab (anti-IgE monoclonal antibody) for severe refractory cases—highly effective in cold urticaria 3, 4
3. Short-course oral corticosteroids (prednisone 20-40 mg for 5-7 days) only for severe flares, not for maintenance 1, 9

Critical Safety Warning

Carry injectable epinephrine if you have a history of: 3, 4

• Systemic symptoms (dizziness, throat swelling, difficulty breathing) with cold exposure 3, 4
• Large body surface area exposure to cold (swimming, winter sports) 3, 4
• Previous anaphylactic reaction to cold 9, 3

Cold-induced anaphylaxis occurs in a minority of patients but can be life-threatening with whole-body cold immersion. 3, 4

Rule Out Secondary Causes

Most cold urticaria in adults is idiopathic (no underlying cause found), but 5-10% have secondary triggers: 1, 9, 3

Order basic screening if symptoms are severe or atypical:

• Complete blood count to exclude cryoglobulinemia or hematologic disorders 1, 3
• Hepatitis B and C serologies if risk factors present 9, 3
• Cryoglobulin testing if systemic symptoms suggest vasculitis 1, 3

Do not perform extensive malignancy or autoimmune workup unless other systemic symptoms are present. 5, 8

Common Pitfalls to Avoid

• Never use sedating antihistamines (diphenhydramine, hydroxyzine) long-term due to dementia risk and cognitive impairment 5, 8, 6
• Do not rely on topical treatments alone—cold urticaria requires systemic antihistamine therapy 2, 3
• Avoid calamine lotion, topical capsaicin, or crotamiton cream—these are ineffective for cold urticaria 7, 8
• Do not assume all cold-triggered rashes are benign—rare familial forms (cryopyrin-associated periodic syndrome) require genetic testing and IL-1 blockade 2, 3, 4

When to Refer to Dermatology/Allergy

• Symptoms persist despite 4-6 weeks of high-dose antihistamines 6, 2
• Atypical cold stimulation test (delayed reaction >30 minutes, negative test with clear clinical history) 2, 4
• Family history of cold-induced symptoms suggesting hereditary forms 2, 3, 4
• Need for omalizumab or other advanced therapies 3, 4