White spots on face can come due to many diseases fungal infection, pityriasis alba,etc etc.
For correct treatment we need to check and diagnose the problem. If it is recurrent problem along with dry skin then most probably it is allergic (happens as a part of atopic dermatitis) which clears in 4-6 weeks with proper treatment.
Next Steps
Consult qualified dermatologist and get it checked for correct diagnosis and treatment
Health Tips
Avoid self treatment