Hi,
It seems that you are having chelitis.
There are many causes.
It may be solar, vitamin deficiencies like
riboflavin, drug induces like retinoidss,
anaemia, internal diseases, irritation,allergic,
stress induced..etc
You should be thoroughly examined and investigated to find out perfect cause.
Treat the cause.
Avoidance of sun exposure, irritant like cosmetics, toothpaste or other chemical should be done.
Take vitamins containing riboflavin and B 12, minerals like Zinc.
Apply moisturiser like liquid parrafin,lactic acid..etc
Take immunobusters.
Do not rupture the skin of lip.
Avoid stress.
Have healthy food and proper sleep.
You
consult dermatologist for perfect diagnosis and treatment.
I hope you might be satisfied with my answer.
Regards.
Dr. Ilyas patel MD