Hi Ross, thanks for your message I forgot to make an update here.
Went to see a GP as it kept happening on and off. Doctor said it's and allergic reaction called Hives, also named Urticaria. Which basically is an allergic reaction to foods, insects, sun, cold, plants, medication, stress. So it could be anything.
Started adiary to try to find out what the allergy is. SHe didn't get any marks after stop sitting on the couch and eating Nutella.. also still taking anti histamine on and daily basis. When itchiness would start we use Calamine chilled in the fridge.
I read that acute Urticaria generally takes 6 weeks..? And happens to 20% of people somewhere in their lives!