Many possibilities for this ranging from reaction to your washing powder or softener or something you might have eaten. I agree with other comments that you should see a doctor. Also you could try an antihistamine tablet.

Itching can be caused by so very many things – if you haven’t had this before, I would suggest seeing a medical professional. In the interim, you could ask your chemist for some advice. For me, if over the counter ointments don’t work after a day, I would definitely be seeing a GP.

I recommend you see GP asap.