if really you are suffering from red scrotum syndrome
then first of all avoid any use of steroids
in any form .
you may start your treatment with doxycycline which is effective for this condition as it has anti inflammatory action as well , take it orally for 4 weeks and then you can switch over to oral gabapentin
for 1 month or so and even if does not work completely then you can also apply topical tacrolimus ointment or cream which will remove the erythematous rashes but for your pain and itching management gabapentin is best.
wish you all the best.