Whiteheads and pimples are two types of blemishes associated with the common skin condition called acne. Both blemishes form as a result of skin changes related to a number of factors, including inflammation and the presence of P. acnes bacteria. The precise location of these changes determines whether you develop a pimple or whitehead.
Acne formation typically begins when the sebaceous glands located inside your hair follicles produce too much of an oily substance called sebum, according to American Academy of Dermatology, or AAD. When this excess sebum blocks the openings of your follicles, also called pores, it can trigger the entrapment of skin debris and provide an excellent breeding ground for P. acnes. In turn, increases in bacteria populations produce inflammation and trigger the formation of acne blemishes. It is the depth and degree of bacterial inflammation inside your follicles that dictates the presence of whiteheads, pimples and other acne symptoms.
Whiteheads belong to a class of "non-inflammatory" acne blemishes called comedones, according to Acne.org. They form when the flow of sebum inside your follicles is trapped close to the surface of your skin. Unlike the comedones called blackheads, the formation of whiteheads completely blocks off the affected hair follicles, the New Zealand Dermatological Society reports. In some cases, this blockage triggers the development of tiny, white spots on your skin's surface. In other cases, whiteheads trigger changes in your skin that can't be seen without some form of magnification. Despite their non-inflammatory classification, whiteheads produce minor inflammation, the AAD notes.
Pimples, also called papules, are a type of inflammatory acne, Acne.org reports. They form at deeper levels than whiteheads, and occur when clogging of your pores leads to the development of ruptures in the walls of your hair follicles. Once these ruptures form, white blood cells from your immune system enter your follicles and trigger the onset of inflammation. If inflammation occurs at a slightly deeper level, you may develop pus-filled pimples called pustules, the AAD notes.
Other Acne Forms
If you develop blockages very deep within your follicles, you may experience particularly intense amounts of inflammation, the AAD explains. This inflammation can trigger the formation of severe acne lesions called nodules, which manifest as large, painful bumps on the surface of your skin. Severe inflammation caused by very deep blockages can also trigger the formation of extremely large, pus-filled acne lesions called cysts. Both nodules and cysts can spread to nearby follicles in your skin, Acne. Org notes.
The AAD lists potential treatments for whiteheads, pimples and other forms of mild acne that include a variety of topical medications with active ingredients such as salicylic acid and benzoyl peroxide. You may also receive topical antibiotics or medications called retinoids. Available forms of these products include creams, lotions and gels. Consult your doctor to learn more about acne medications and appropriate home care options. Together, you and your doctor can make a detailed treatment plan that fits the particulars of your situation.