Thanks for the query,
You might be suffering from an autoimmune disorder.
Lupus or rheumatoid arthritis
may be thought of.
Your description matches with this.
Please get an ANA profile done.
This will bring out what exactly is going on.
Treatment is with anti histamines
Steroids might be required if it is severe.
Please meet a dermatologist
for exact diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.