hi, thanks for your query
You seem to have probably developed lupus like syndrome with minocycline
characterised by joint pain, stiffness
or swelling of joints, fever, muscle pain
, skin rash, inflammation of blood vessels.
Benedryl is antihistaminic will help in reduction of the rash and itching so it is helpful but it is better to rule out any serious side effects or minoxidil
You must stop taking the tablets and contact ER as early as possible.
Hope this helps you
Wishing you a speedy recovery