My wife takes antihistamines for itchy skin (as well as moisturiser)... you can buy the shops own branded ones (very cheap from Tesco) look for the ones with 'Cetirazine' - You don't need Piriton, Zirtek etc... they use exactly the same ingredients.
If you go to a Tesco with a pharmacy you can buy boxes of thirty over the counter... otherwise they come in boxes of 7.