Hopefully this may help some people
I have always had bad reactions to insect bites. However in the last twelve months it has got incredibly worse. I have got badly bitten in December and January needing antibiotics twice. I have awful demarcation on the tops of my legs that looks like someone has beaten me up (incidentally I get bitten through my clothes. December and January are cold up north). The last nurse I spoke to in February said there in evidence to suggest that people with a B12 and/or iron problem are more likely to react this way.
Always use your insect repellent if you are finding this is an issue. Home Bargains sell a brand that contains citronella so doesn’t smell so bad.
Good luck 😁