Angular cheilitis can be caused by
diabetes, systemic corticosteroid or antibiotic use.
Dentures, especially if they are poor fitting, and there is associated gum recession
Poor nutrition: coeliac disease, iron deficiency, riboflavin deficiency
Systemic illness, particularly IBD.
Sensitive skin, especially atopic dermatitis
Oral retinoid medication: isotretinoin for acne, acitretin for psoriasis.
So it’s better to find the cause first before treatment
Next Steps
Consult online.