Middle, outside bottom lip developed a rough patch. no pain or tingling but not much feeling. only slightly redder than lips. started 3 days ago?

If not a cold sore..: Some roughness and mild redness on a lip can be lip eczema, which may be treated like skin eczema, using hydrocortisone cream (twice a day for 1 week) plus Vaseline or Aquaphor to retain moisture. Sometimes lip balm or lip sunscreen chemicals cause an allergic reaction. Other times a person is a primary lip-licker (it's her habit). Once cracked, lips can get irritated by routine foods and juices.