How should I manage acute allergic swelling of the hands?

Management of Acute Allergic Swelling of the Hands

For acute allergic hand swelling without airway involvement, administer oral antihistamines (H1 blockers) combined with cold compresses and close observation; if symptoms are severe or progressive, add a short course of oral corticosteroids and consider intramuscular epinephrine if systemic symptoms develop. 1

Immediate Assessment

Determine if this is isolated hand swelling or part of a systemic reaction:

• Check for urticaria (hives), pruritus, or swelling elsewhere – these indicate histamine-mediated allergic reaction 2, 3
• Assess for respiratory symptoms (wheezing, throat tightness, difficulty breathing) or cardiovascular symptoms (hypotension, dizziness) – these require immediate epinephrine 1
• Ask about recent insect stings, food exposure, or new medications – helps identify trigger 1

Treatment Algorithm Based on Severity

Mild to Moderate Hand Swelling (No Systemic Symptoms)

First-line treatment:

• Oral H1 antihistamine immediately: Second-generation agents like cetirizine 10-20 mg or loratadine 10 mg are preferred over first-generation diphenhydramine due to less sedation 4
• Cold compresses to the affected hands to reduce local swelling and discomfort 1
• Elevate the hands to reduce edema 1

If inadequate response within 1-2 hours:

• Add H2 blocker: ranitidine 150 mg or famotidine 20 mg orally 1, 3
• Consider oral corticosteroid: prednisone 0.5-1 mg/kg (maximum 60-80 mg) for severe local swelling 1

Severe Hand Swelling or Any Systemic Symptoms

Administer intramuscular epinephrine 0.3-0.5 mg (0.01 mg/kg in children, max 0.3 mg) in the anterolateral thigh immediately if the patient has: 1, 5

• Difficulty breathing or throat tightness
• Hypotension or dizziness
• Widespread urticaria beyond the hands
• Gastrointestinal symptoms (nausea, vomiting, abdominal pain)

Additional acute management:

• IV diphenhydramine 50 mg (1-2 mg/kg in children) 1, 3
• IV methylprednisolone 125 mg (1 mg/kg in children) 1, 3
• H2 blocker: ranitidine 50 mg IV or famotidine 20 mg IV 1, 3
• Transport to emergency department for monitoring 1

Critical Differentiation: Rule Out Bradykinin-Mediated Angioedema

If hand swelling occurs WITHOUT urticaria or pruritus, consider bradykinin-mediated angioedema (hereditary or ACE inhibitor-induced), which requires completely different treatment: 2, 3, 6

• Ask specifically about ACE inhibitor use (lisinopril, enalapril, etc.) 2, 3
• Ask about family history of recurrent swelling episodes 2, 3
• Note if swelling developed slowly over hours rather than minutes 3

For bradykinin-mediated angioedema, standard allergy treatments (antihistamines, corticosteroids, epinephrine) are completely ineffective – these patients require plasma-derived C1 inhibitor concentrate 1000-2000 U IV or icatibant 30 mg subcutaneously and urgent specialist referral 2, 3, 6

Observation and Follow-Up

• Observe for 2-4 hours minimum after treatment to ensure no progression or biphasic reaction 1, 3
• Prescribe epinephrine auto-injector (2 doses) if any systemic symptoms occurred, with instructions for self-administration 1
• Discharge antihistamine regimen: Continue H1 antihistamine (cetirizine 10 mg or loratadine 10 mg) daily for 2-3 days 1
• Consider short corticosteroid course: prednisone 40-60 mg daily for 2-3 days if swelling was severe 1

Referral to Allergist-Immunologist

Refer for allergy consultation if: 1

• Recurrent episodes of unexplained swelling
• Unclear trigger despite thorough history
• Need for skin testing or specific IgE testing to identify allergen 3
• Patient requires education on allergen avoidance and emergency management 1

Common Pitfalls to Avoid

• Do not delay epinephrine if any signs of systemic reaction are present – fatal reactions are associated with delayed epinephrine administration 1, 6
• Do not assume infection – allergic swelling is caused by mediator release, not infection, and antibiotics are not indicated unless secondary infection is evident 1
• Do not use epinephrine, antihistamines, or corticosteroids for bradykinin-mediated angioedema – they waste critical time and are ineffective 2, 3, 6
• Do not discharge patients with oropharyngeal involvement prematurely – these require extended observation due to airway risk 2, 3