Face it. Except for the very lucky, few of us are able to escape biting insects. After getting bit, the range of reactions is immense; from no reaction to anaphylaxis. Thankfully, most simply have mild pruritis and urticaria. But how are we supposed to treat these?
This review article from the UK lays out the evidence behind all the common treatments for bug bites. Here is a summary:
- Oral antihistamines are recommended, but data is lacking. A review consisting mostly of multiple studies from one group in Finland showed them to be effective.
- Use non-sedating antihistamines during the daytime, and sedating ones as night.
- Topical antihistamines don’t work well, can cause sensitization, and aren’t recommended for longer than 3 days.
- Topical corticosteroids are poorly studied but may be effective.
- Topical corticosteroids shouldn’t be used on broken skin or on the face.
- Oral corticosteroids are used for severe urticaria, but no studies have been found to support this.
- Use the lowest dose for the shortest time possible for oral corticosteroids.
- OTC analgesics can be used for pain, but topical anesthetics can cause sensitization.
- Calamine isn’t the slightest bit effective, so don’t use it.
- Counter-irritants (such as dilute ammonium) may be effective based on one double blind RCT.
- Topical antiseptics after bites are probably overkill.
- Generalized symptoms or redness/swelling over 10cm should be referred to an allergist.
- Secondary infections should be treated with antibiotics.
- Treat anaphylaxis appropriately.
Nothing earth shattering here, but maybe this will prevent unnecessary topical treatments which are often ineffective and possibly harmful. I do wish more people would recommend loratidine or cetirizine for this instead of diphenhydramine. The sedating effects as well as the duration of effect would tend to recommend the newer, now OTC agents, but I still see most everyone giving patients prescriptions for Benadryl®.
Management of simple insect bites: where’s the evidence? Drug Ther Bull. 2012 Apr;50(4):45-8. [PMID 22495051]
EBM Gone Wild