What are the recommended first-line treatments for localised reactions to insect bites and stings in adults?

First-line treatments for localized reactions to insect bites and stings in adults usually involve simple first aid measures such as cleaning the area and applying cold compresses to reduce pain and swelling.

Oral analgesics like paracetamol or ibuprofen may be recommended to ease pain, although evidence supporting their effectiveness is limited.

Oral antihistamines (e.g., chlorphenamine) or topical corticosteroids (e.g., hydrocortisone 1%) can be used to help reduce itching, but their use is generally off-label and lacks strong quality evidence.

Topical antipruritics, topical antihistamines, and topical anaesthetics sold over-the-counter have uncertain value and may cause irritant skin reactions, so they are not routinely recommended.

For large local reactions, oral antihistamines and/or corticosteroids are often used, but again this is off-label and evidence is lacking; corticosteroids should not be prescribed if infection is suspected.

Overall, the mainstay for localized reactions is simple first aid and symptomatic relief with oral analgesics and antihistamines or topical corticosteroids as needed, with caution regarding off-label use and potential adverse effects.