Have you ever had a henna tattoo?
Hello and hope you are doing well.
The reaction could be due to anything in the product. Since you have been using the product for years check to see if any new additional ingredients have been added, this could account for your allergic reactions. Sometimes even with the same ingredients you can develop an allergy to the product, as the allergy develops in response to a repeated stimulus.
Hope this helped and do keep us posted.