itching is a common problem.
but remedies for itching is not always hydrocortisone/steroid
probably you have ringworm.
so, h.cortisone should not be used here.
itching can be controlled by antihistaminics.
now good antifungals are available.
with simple test we can detect fungal infection
these are easily amanable to treatment.
but if nails are involved then duration of treatment will be more.
so consult a dermatologist
and get wells soon.