What is the treatment for insect bites?

From the Guidelines

The treatment for insect bites typically involves managing symptoms and preventing infection, with the primary goal of reducing morbidity, mortality, and improving quality of life. For most insect bites, washing the area with soap and water, then applying a cold compress to reduce swelling and pain is recommended 1. Over-the-counter medications like hydrocortisone cream (0.5-1%) can be applied 2-3 times daily to reduce itching and inflammation, while oral antihistamines such as diphenhydramine (Benadryl, 25-50mg every 4-6 hours) or non-sedating options like cetirizine (Zyrtec, 10mg daily) can help control itching and allergic reactions 1. For pain relief, acetaminophen (Tylenol, 325-650mg every 4-6 hours) or ibuprofen (Advil, 200-400mg every 4-6 hours) can be effective. Avoid scratching the bite to prevent infection. If the bite area shows signs of infection (increasing redness, warmth, swelling, pus, or red streaks), seek medical attention as antibiotics may be needed. For severe allergic reactions with symptoms like difficulty breathing, facial swelling, or dizziness, use an epinephrine auto-injector if available and seek emergency medical care immediately, as delayed use of epinephrine can be ineffective and even fatal 1. Some key considerations for managing acute reactions to stings include:

• Treating acute systemic reactions to insect stings like any anaphylactic reaction, with epinephrine injection, supportive therapy, and transport to an emergency department 1
• Using antihistamines and close observation for initial treatment of cutaneous systemic symptoms in patients with a history of only cutaneous systemic reactions 1
• Considering a brief course of oral corticosteroids for treatment of large local reactions, although antibiotics are usually not necessary unless there is evidence of secondary infection 1
• Educating patients on how to avoid insect stings, carry epinephrine for emergency self-treatment, and undergo specific IgE testing for stinging insect sensitivity and consideration for immunotherapy 1

From the FDA Drug Label

Emergency treatment of allergic reactions (Type I), including anaphylaxis, which may result from allergic reactions to insect stings, biting insects, foods, drugs, sera, diagnostic testing substances and other allergens, as well as idiopathic anaphylaxis or exercise-induced anaphylaxis. Uses For temporary relief of itching associated with minor skin irritations, inflammation and rashes due to: ● eczema ● seborrheic dermatitis ● psoriasis ● insect bites ● poison ivy, oak, sumac ● soaps ● detergents ● cosmetics ● jewelry ● external feminine genital and anal itching

The treatment for insect bites includes:

• Epinephrine (IM) for emergency treatment of allergic reactions (Type I), including anaphylaxis caused by insect bites 2
• Hydrocortisone (TOP) for temporary relief of itching associated with minor skin irritations and inflammation due to insect bites 3

From the Research

Insect Bite Treatment

• Insect bites can be prevented by having knowledge of insect behavior, and individuals allergic to insect stings should carry an epinephrine injection kit as a first aid measure 4.
• For those who travel far from medical facilities, carrying prednisone and oral antihistamines is also recommended 4.
• The bite of a brown recluse spider may cause a minor reaction or extensive soft-tissue necrosis, and if necrosis occurs, a course of oral dapsone is recommended 4.

Allergic Reactions to Insect Bites

• Insect stings are an important cause of anaphylaxis, and anaphylaxis can also occur from insect bites, although it is less common 5.
• Effective methods to diagnose insect sting allergy and assess risk of future sting reactions have been developed, and management strategies using insect avoidance measures, self-injectable epinephrine, and allergen immunotherapy are very effective in reducing insect-allergic patients' risk of reaction from future stings 5.

Management of Simple Insect Bites

• Simple insect bites are those that are not accompanied or followed by anaphylactic shock or systemic infection, and many preparations for the treatment of insect bites, including antihistamines and topical corticosteroids, are available for purchase over the counter (OTC) in the UK 6.
• However, there is a lack of evidence for the efficacy of these treatments, and recommendations for treatment are based on expert opinion and clinical experience 6.

Efficacy of Concentrated Heat for Treatment of Insect Bites

• The use of concentrated heat for relief of symptoms caused by insect bites may be a promising approach, and a real-world study found that local application of heat relieves symptoms of insect bites, including itch and pain 7.
• The study found that mosquito bite-induced itch was reduced by 57% within the first minute and by 81% 5-10 min after treatment, and the overall reduction in itch and pain was more pronounced than in the control group 7.

Antibiotic Usage for Insect Bites

• Insect bite inflammation may mimic cellulitis and promote unnecessary antibiotic usage, contributing to antimicrobial resistance in primary care 8.
• A study found that antibiotics were prescribed to nearly three-quarters of patients with insect bites, mainly orally and mostly as flucloxacillin, and that flucloxacillin for insect bites contributed a mean of 5.1% of total practice flucloxacillin prescriptions 8.