It is possible to get a pimple on the outside of the lip. However, many lip lesions are actually cold sores. Pimples are distinguished from cold sores because pimples begin with a slight tenderness in the affected area.
A lip pimple is more rigid than a cold sore, which is filled with fluid. Over-the-counter acne creams are used to treat pimples. Many contain benzoyl peroxide. Hydrocortisone cream helps reduce swelling if it appears. Refraining from repeatedly touching the pimple also encourages healing. In contrast, cold sores are treated with non-prescription medications such as Abreva, although sometimes prescription antiviral creams or oral medicines are needed to prevent reoccurring problems.