Difference Between Cold Sore and Pimple

Cold Sore and Pimple are of different causes. Also, cold sores are blisters that appear in clusters and are infectious and pimples are physiological and uninfected pimples are not blisters nor contagious. However, understanding the difference between cold sore and pimple may help to address the problem at an early stage.

Cold Sore

Cold sores are also known as fever blisters. They occur outside the mouth and genitalia. They occur in clusters, and the skin around the blisters is warm, reddened and painful. These blisters rupture overtime and exude a clear, straw colored fluid and crust over. Healing takes around one to two weeks. Fever, enlarged lymph nodes, runny nose, malaise, loss of appetite may accompany the sores.

Diagnosis of cold sore is clinical. This condition is self-limiting and treated if they are very painful. Antiviral skin creams, ointments can be used, sometimes in concert with oral treatment in severe cases. Cold sores can be prevented by using separate drinking cups, plates, and cutlery, proper hand-washing and avoiding kissing an infected person. Direct exposure to sunlight may induce a flare up. Herpes simplex virus (HSV) type 1 and 2 both cause cold sores. Some individuals carry the virus without having symptoms. HSV is transmitted via direct contact and is very contagious. Sharing eating utensils, sharing shaving equipment, coming into contact with saliva of an infected person are some common routes of transmission. It enters the body through damaged skin and mucus membranes.


Pimple is a localized globular elevation in the skin due to blockage of skin pores. Sebaceous glands secrete sebum which is channeled onto the skin surface. These channels are blocked by dead skin cells which are shed from the skin. Sebaceous glands continue to secrete sebum which accumulates behind the block forming the bleb. This sebum is a good culture medium for bacteria. Propionibacterium acne is the most common organism that grows in these blocked channels. Infected acne result in a pustule surrounded by red, tender skin.

Acne do not need treatment unless severe. Many over-the-counter medications containing salicylic acid, triclosan, nicotinamide, clindamycin and benzoyl peroxidase are available. Prescription antibiotics such as erythromycin and tetracycline have been shown to be effective against severe cases of acne. Skin hygiene is of critical importance in treating acne. A combination of good skin cleansing and a topical antibacterial application is usually adequate to keep acne under check.

Cold Sore vs Pimple

• Cold sores are blisters, and uninfected pimples are not.

• Cold sores are caused by a virus while a formed pimple is infected by a bacterium.

• HSV is the cause of the sore while P. acne is not the cause of pimples.

• Cold sore is caused by an exogenous pathogen while pimples are physiological.

• Cold sores can be treated with antiviral drugs and infected pimples need antibiotics.

• Cold sores can transmit the virus via direct contact while uninfected pimples are not contagious.