HappySecret, I expect the pharmacist was looking at something like the British National Formulary . He is right in that Appendix 4 of the BNF which is about information on safety of drugs in pregnancy does not actually mention Piriton. However the drug's SPC says:
`There is inadequate evidence of safety in human pregnancy. Piriton Tablets should only be used during pregnancy when clearly needed and when the potential benefits outweigh the potential unknown risks to the foetus. Use during the third trimester may result in reactions in neonates.
It is reasonable to assume that chlorphenamine maleate may inhibit lactation and may be secreted in breast milk. The use of Piriton preparations in mother's breast feeding their babies requires that the therapeutic benefits of the drug should be weighed against the potential hazards to the mother and baby.'
So, the manufacturer does not recommend its use. This is because, as JennyWren says, they have no clinical trial data because pregnant women are usually excluded from clinical trials. So they cannot say that it is safe. But it has been used by many pg women without ill effects (according to what I have read and to the GP I saw).
Which kind of Eurax have you been using? Is it hydrocortisone? I had a severe contact dermatitis during my last pg and I was given betamethasone valerate. However, I think the doctor might have been nervous about prescribing such a strong steroid if I had not been nearly 40 weeks by then.
Do you mind me asking what the allergy is to? Is there any way in which you can reduce contact with the allergen? Which antihistamine are you using at the moment? I was lucky in that I could remove my contact with the allergen but the reaction flared up dramatically even after I had done this - I don't know whether that was something to do with being pg. The PUPPP started shortly after the contact dermatitis too, so I don't know if that might have been related (PUPPP is also an allergic condition).