What is the treatment for raised hives (urticaria) after mosquito bites?

Treatment for Raised Hives After Mosquito Bites

Antihistamines are the first-line treatment for raised hives (urticaria) following mosquito bites, with non-sedating H1 antihistamines being the preferred initial therapy. 1

First-Line Treatment

Non-Sedating H1 Antihistamines

• Start with a standard dose of a non-sedating H1 antihistamine:
  • Cetirizine 10mg once daily
  • Loratadine 10mg once daily
  • Desloratadine 5mg once daily
  • Fexofenadine 180mg once daily
  • Acrivastine 8mg three times daily 1

Management Approach

1. Initial management:

   • Clean the bite area with soap and water to prevent secondary infection
   • Apply cold compresses for 10-15 minutes several times daily to reduce swelling and itching 2

2. For inadequate response to standard doses:

   • Increase the dose of non-sedating antihistamine up to 4 times the standard dose (off-label but supported by guidelines) 1
   • For example: Cetirizine 20-40mg daily or Fexofenadine up to 720mg daily

3. For nighttime symptoms:

   • Consider adding a sedating antihistamine at night (e.g., diphenhydramine 25-50mg or chlorphenamine 4-12mg) 1, 3

Second-Line Options

Combination Therapy

• Add an H2 antihistamine to the H1 antihistamine regimen for better control 1
  • Options include ranitidine 150mg twice daily or cimetidine 300mg four times daily

Topical Treatments

• Topical corticosteroids for localized reactions
• Topical lidocaine (if skin is intact) for pain relief 2

Short-Term Systemic Corticosteroids

• Consider for severe, widespread reactions not responding to antihistamines
• Short course of prednisone (e.g., 20-40mg daily for 3-5 days) 4
• Note: Evidence for adding corticosteroids to antihistamines in acute urticaria is mixed 4

Special Considerations

For Severe Reactions

• If signs of anaphylaxis develop (difficulty breathing, dizziness, hypotension):
  • Administer epinephrine immediately (0.3-0.5mg IM in adults)
  • Seek emergency medical attention 2

For Recurrent Severe Reactions

• Refer to an allergist-immunologist for evaluation 1
• In rare cases of confirmed mosquito bite anaphylaxis, immunotherapy with whole body mosquito extracts may be considered, though this carries risks 5

Prevention Strategies

• Use insect repellents containing DEET
• Wear protective clothing
• Avoid outdoor activities during peak mosquito hours
• Consider prophylactic antihistamines during mosquito season for susceptible individuals 6, 7

Follow-up Recommendations

• If symptoms persist beyond 48-72 hours despite treatment
• If signs of secondary infection develop (increasing redness, warmth, pain)
• If systemic symptoms occur at any point

Most mosquito bite reactions are self-limiting and will resolve within a few days with appropriate antihistamine treatment. Persistent or recurrent severe reactions warrant further evaluation by an allergist.