Small white bumps on the lips can be caused by several things, including acne, cold sores, sunburn, allergies, infection, trauma and cancer, according to New Health Guide. While most causes are benign and do not require medical treatment, the site recommends seeing a dermatologist for a professional diagnosis as some types of bumps may spread or get worse.
Bumps along the bottom lip line are often caused by acne breakouts, according to Med-Health.net. One type of benign bump called Fordyce's spots causes painless papules that look similar to pimples. These spots often appear in clusters and are sometimes found on other parts of the body, such as the cheeks and genital area.
Painful bumps may indicate infection, cold sores and trauma caused by lip biting. White bumps caused by sunburn often feel like sandpaper and may cause pain, according to New Health Guide.
Although rare, white spots may also indicate oral cancer. Bumps caused by malignant tissue often go through changes such as ulceration, bleeding and infection, according to New Health Guide. The bumps and discoloration might also migrate to other parts of the mouth, such as the gums, the inside of the cheeks and the tongue. A biopsy is necessary to diagnose or rule out cancer.