As per your history, this is second attack of itchy rash on face.
It looks like contact dermatitis
of allergic origin. Observe if you are exposing yourself to specific soap/water/powder/cream. It might give allergy.
If itchy rash is throwing silvery-red scales- it indicates psoriasis; which will need specific treatment.
So continue allegra
for 3 more days. Apply calamine
lotion, cold compresses on rash. If it doesnt come down or shows scales or other discomfort like pain; then you need to consult dermatologist