I sometimes get a bit overwhelmed by mozzie bites in summer, Eliza (horsefly bites don't bother me). I hate putting on repellent, that's the trouble, especially the only one that seems to work (DEET). Last summer I bought some of that Piriton stuff you mentioned, thinking that it would calm down the bites while I was in bed. It worked a treat, but it also turned me into a 12-hour zombie! I found that the two weaker ones, ceterizine and loratidine, did the trick and gave me a good night's kip. I'm not recommending anything here, as we're all different and we shouldn't be handing out medical advice, just responding to your mention of Piriton!