What is the recommended medication treatment for a bug bite?

Medication Treatment for Bug Bites

Immediate Local Reactions (Non-Allergic)

For typical bug bites causing localized redness, swelling, and itching, symptomatic treatment with topical antihistamines or oral antihistamines combined with cold compresses is recommended, while antibiotics should be avoided unless clear signs of secondary bacterial infection develop. 1, 2

First-Line Symptomatic Treatment

• Cold compresses reduce local pain and swelling effectively 1, 2
• Oral antihistamines (such as cetirizine) reduce itching and pain associated with cutaneous reactions 1, 2, 3
• Topical pramoxine can alleviate pruritus in bed bug bites 4
• Oral analgesics help manage pain 2

For Severe Local Reactions

• Topical corticosteroids control inflammation and pruritus, hastening resolution of significant eruptions 4
• Oral corticosteroids may be used for severe large local reactions (such as extensive wasp sting reactions), though definitive proof through controlled studies is lacking 1, 2

Critical Pitfall: Avoiding Inappropriate Antibiotic Use

Do not prescribe antibiotics for typical bug bite reactions—the swelling is caused by allergic inflammation and mediator release, not bacterial infection. 1, 2

• Large local reactions to insect stings are IgE-mediated allergic responses that peak at 24-48 hours and can last up to a week, commonly misdiagnosed as cellulitis 1
• The American Academy of Allergy, Asthma, and Immunology specifically warns against mistaking allergic swelling and lymphangitis for bacterial cellulitis 1
• Antibiotics are indicated only when clear evidence of secondary bacterial infection exists: purulent drainage, fever, or progressive worsening beyond 48-72 hours despite anti-inflammatory treatment 1, 2

Anaphylactic/Systemic Reactions

Epinephrine is the drug of choice for anaphylaxis from insect bites or stings, administered as 0.3-0.5 mg intramuscularly in the anterolateral thigh for adults (0.01 mg/kg up to 0.3 mg in children). 5, 6

Emergency Management

• Intramuscular injection in the anterolateral thigh achieves more rapid and higher plasma concentrations than subcutaneous or arm injection 5
• Delayed use of epinephrine may be ineffective; fatal outcomes are associated with delay or lack of epinephrine administration 5
• Repeat dosing may be required for persistent or recurrent symptoms 5
• Antihistamines and corticosteroids are NOT substitutes for epinephrine in systemic reactions 5, 2

High-Risk Patients

• Patients with previous systemic reactions to insect stings should carry injectable epinephrine at all times 5
• Consider prescribing more than one epinephrine injector as some patients require multiple doses 5
• There is no contraindication to epinephrine in life-threatening anaphylaxis, even in patients with cardiovascular disease or those taking β-blockers 5

Specific Bite Types

Tick Bites (Lyme Disease Prevention)

• Single-dose doxycycline 200 mg (4.4 mg/kg up to 200 mg in children) within 72 hours of removal for high-risk Ixodes tick bites only 5
• High-risk criteria: identified Ixodes species, highly endemic area, and tick attached ≥36 hours 5
• Do not use prophylactic antibiotics for equivocal or low-risk tick bites 5

Animal Bites

• Amoxicillin-clavulanate 875/125 mg twice daily is first-line for animal bites requiring antibiotic prophylaxis or treatment 5
• Alternative: Doxycycline 100 mg twice daily has excellent activity against Pasteurella multocida from cat/dog bites 5

Bed Bug Bites

• Treatment is symptomatic: topical pramoxine, oral antihistamines, and topical corticosteroids for significant eruptions 4
• Reactions are self-limited and do not require antibiotics 4

Patient Education Priorities

• Teach patients to recognize signs of true infection versus allergic inflammation 1, 2
• Patients with large local reactions have up to 10% risk of eventual systemic reaction; consider prescribing epinephrine autoinjector for reassurance 2
• Instruct on proper epinephrine administration technique and circumstances for use 5