Causes Of Pimple On Lip. Causes of pimple on lips. Allergic reaction to cosmetics.

Lips are one of the most sensitive. Pimples appearing on the bottom lip are most like to be caused by Waxing or threading which cause the damage and irritation of the hair follicles appearing the lower lip. Your actual lips do not have any hair follicles so if the lesion is on your actual lip you may have a cold sore.
Excess oil dead skin cells and bacteria are number one culprits for pimples on lip.
Smoking also increases the chances of developing mouth cancer that can also result to bumps on the lips. Tobacco smoke contains toxins or harmful chemicals that causes irritation of the lips. Eating greasy food might not cause breakouts internally. Using poor quality lipsticks lip balms or lip stains can deliver infectious bacteria to the skin.