Yes you can treat ringworm with hydrocortisone cream.
The best hydrocortisone cream that worked my ring work was the Canesten Plus Clotrimazole & Hydrocortisone Cream which is a combined anti inflammatory and anti fungal cream that works to attack the cause of the infection causing the Ringworm.
If you can't get the above cream usually any athlete foots cream or other anti fungal cream will work to get rid of ringworm.