Hello and welcome to healthcaremagic
I am Dr. Kakkar. I have gone through your query.
I would keep a possibility of Angular Cheilitis/Perleche.
I would suggest an oral B-complex vitamin + Zinc supplement
(Cap Becosule-Z) once daily for 3-4 weeks.
Topically you could apply a mild steroid
+ antifungal combination cream e.g Eumosone- M cream OR Clotrin- B cream, twice daily for 7-10 days.
That should make it fine