Acne and cold sores are both lesions that occur on the face. They can look similar. However, they have different causes, they can be distinguished visually as well as by their location on the face, and their treatment differs. Most importantly, cold sores are infectious, while acne lesions are not.
Causes
Acne occurs when hair follicles in your skin become clogged with sebum--the oil your skin produces to keep itself from drying out. Excess sebum production occurs with increases in the production of hormones known as androgens. Cosmetics that block pores, as well as restrictive clothing and sweating, can contribute to the development of acne. In contrast, cold sores result from reactivation of herpes simplex virus 1, or HSV-1. After an initial infection with HSV-1, the virus lays dormant in nerve cells in your body. Periods of stress and other triggering events can cause HSV-1 to re-activate, at which point it migrates to the surface of your skin to form characteristic herpes lesions.
Appearance
The lesions of acne and cold sores look different. Acne often takes the form of whiteheads, which are small flesh-colored or white bumps, or blackheads, which are small flesh-colored or white bumps with a black center. As acne lesions grow larger, they may become inflamed, forming solid, red bumps. Finally, acne lesions can become infected, in which case pus, or a crusty exudate, may be visible on the surface. In contrast, cold sores tend to take the appearance of several small, fluid-filled blisters on a red base
Location
Acne occurs most commonly on the face, back, neck and shoulders, although it can occur in other places. In contrast, cold sores occur most commonly along the border between the lip and the rest of the face, and less commonly, on the inside of the mouth, on the hard palate.
Epidemiology
Although anyone can get acne, it is most common in teenagers and young adults, and can occur along with pregnancy or during the premenstrual period of the menstrual cycle in women, as a result of an excess of hormones driving the production of sebum. Cold sores result from a reactivation of HSV-1, with which a majority of American adults are infected. Reactivation can occur at any time, although it is more common when a person is feverish, giving rise to the term "fever blisters" as a description of cold sores, and reactivation tends to decrease after age 35.
Treatment
Usually, treatment for acne is topical, and options for treatment vary depending on the severity of the acne. These include benzoyl peroxide, tretinoin and topical antibiotics. Oral preparations may be used if topical treatment is impractical. Rarely, steroids may be used. Cold sores are treated with anti-herpes medications, including topical acyclovir and valacyclovir. If you are concerned that you have acne or cold sores, you should see your doctor for diagnosis and treatment.
