Hi, it is an allergic reaction
to some items, like chillies. i advise you to one variety of chillies, say red chillies, and observe for one week.if you don't get itching stop it and take green chillies, then paprika. The avoid the chillies giving the itching.
If you get with all the 3 , and you want to have them by any means you consult a allergy
specialist , who will try to reduce the allergy.