Try clove
Oil mixed with a little water. I believe from all I have read that it is
Nerve endings from your spine and neck and the nerves are attached to ur arms etc. Try using the oil and keep ur skin moisturized all the time and keep all problem areas away from light as this problem seems to be photo sensitive. I always ware long sleeves as my problem is on my arms. I TRULY got great comfort from taking amitriptaline (sorry about spelling) which was prescribed by my GP. Thank God for them they have
Made a big difference and of course u know to use ice when the itch is very bad.