You would not believe it but I spent a day and a night of my holiday in hospital following an extreme allergic reaction to a mosquito bite.
It went beyond a hard red infected lump (my normal reaction) that lasts a couple of weeks. I'm talking a football sized weal. A massive inflated ball. Someone did actually scream when they saw me. It was not funny.
So please do take creams and potions on holiday with you and if you do get bad lumps when bitten, it's worth checking with your GP as to whether to take an anti-histamine with you.
Here's a useful site:
"http://www.beyondallergy.com/skin-allergies/mosquito-bite.php"