This is burning mouth syndrome. Exact cause is difficult to say but i am mentioning some local and systemic cause, it might help you. :-
LOCAL -
*candidal infection ,denture wear, decreased salivary outout, parafunction oral habit.
SYSTEMIC -
nutrional deficiency, iron deficiency anemia, harmonal changes like
diabetes,
thyroid, some drugs
Next Steps
As your condition is initial, i am suggesting you few medication .1.CAPSAICIN GEL 0.025% (brand name -capsain-p). 2Multivitamin (
B12,methyl cobalamin and folic acid) initially for 15days ,if it give you benefit then continue for 1 month. .
Health Tips
you can also use Alpha-lipoic acid for mouth rinsing twice daily for 1 month. (ALA -100,ALADIN 100 mg)