Itchy spots that disappear quickly

[NorthernBey]

For the last three weeks I've been getting isolated itchy bumps on my skin. They usually appear on my belly, arms or thighs. They occur just one at a time and then disappear within a few hours. They are only a few mm wide, red and itchy.
I have had at least one a day for the last few weeks.
I had my booster a month ago and this started a week later. We also changed laundry detergent a couple of months ago, but I'd imagine that would appear as a rash.
Any ideas?

I’ve been suffering with this all week but my body is now pretty much covered. I went to the Dr yesterday and she diagnosed Urticaria and prescribed antihistamines. If yours is milder an OTC antihistamine is probably enough if you feel uncomfortable.

Coincidentally I had my booster last week and I did wonder if that was the trigger. I have used a different washing powder this week but we change a lot as we just buy whatever is on offer. The Dr said for a first outbreak it’s best just work on managing the symptoms for now as it’s likely a one off.