Hello. Thank you for writing to us A white patch on face could be either of Pityriasis alba which is actually due to post-inflammatory hypopigmentation Or it could be a patch of Vitiligo which is due to complete absence of melanin. They can be easily distinguished clinically. Pityriasis alba is more common in dry skin. It presents as faintly white, ill-defined, asymptomatic hypopigmented patches, commonly on face. Vitiligo on the other hand is completely de-pigmented i.e devoid of melanin and is milky-white in color. If I was the treating doctor I would have suggested you to use a topical immunomodulator e.g tacrolimus ointment, twice daily. It should be rubbed in gently. It is a prescription drug and therefore I suggest that you talk to your doctor for a confirmatory diagnosis as well as for the needful. Tacrolimus is first line treatment for patches of vitiligo as well as Pityriasis alba. Regards