Whiteheads and blackheads are not identical, though they share a common origin as non-inflammatory acne lesions known as comedones. Both types represent a form of pore blockage, but the key difference lies in whether the pore’s opening is sealed or open to the air. This structural distinction dictates their appearance and the most effective approach to treatment.
The Shared Formation Process
The formation of whiteheads and blackheads begins within the pilosebaceous unit, which includes the hair follicle and the attached sebaceous gland. This gland produces sebum, an oily substance that lubricates the skin and hair. Overproduction of sebum, often influenced by hormones, leads to a buildup in the follicle. This excess oil mixes with dead skin cells (keratinocytes) that are not shed properly. This combination forms a plug that obstructs the pore’s canal, which is the fundamental starting point for all comedones.
Whiteheads: Closed Comedones
A whitehead is technically termed a closed comedo because the pore’s opening remains completely covered by a layer of surface skin cells. This sealed barrier traps the mixture of sebum and dead cells beneath the skin, creating a small, raised bump. Since the contents are not exposed to the atmosphere, the material retains its original whitish or yellowish color. These lesions appear as small, flesh-colored or creamy-white bumps on the skin’s surface. Because there is no opening, the trapped material cannot react with oxygen. This lack of oxidation means whiteheads do not develop a dark color, instead appearing as a firm, subtle bump.
Blackheads: Open Comedones
In contrast, a blackhead is classified as an open comedo, meaning the follicular opening is enlarged and exposed to the environment. The plug of oil and dead skin cells remains in the pore, with the top portion open to the air. This exposure triggers oxidation, a chemical reaction affecting the melanin and lipids within the trapped debris. The dark color is not caused by dirt, as is commonly believed, but is the direct result of this oxidation process. When the contents react with oxygen, the material turns dark brown or black, creating the characteristic “black dot” appearance. This open pore structure allowing oxidation visually distinguishes a blackhead from a whitehead.
Targeted Treatments for Each Type
Because whiteheads are sealed and blackheads are open, treatment strategies target the different structures of the lesions.
For whiteheads, the primary goal is to encourage skin cell turnover to unseal the blockage and allow the material to exit the follicle. Topical retinoids, such as adapalene, are highly effective because they normalize the shedding of skin cells and reduce the keratin that is sealing the pore. The closed nature of whiteheads makes physical extraction difficult and ill-advised to attempt at home, which can lead to scarring.
For blackheads, the focus is on dissolving the existing plug and keeping the pore clear. Beta hydroxy acids (BHAs), specifically salicylic acid, are beneficial because they are oil-soluble and can penetrate the pore to break down the debris inside. Ingredients like clay or charcoal, often used in masks, can also help by absorbing excess sebum and drawing impurities out of the open pore.
For both types of comedones, consistency with products that promote exfoliation and cell turnover is necessary. Topical retinoids are often considered the most effective therapy for both open and closed comedones due to their ability to regulate cell growth and prevent future blockages.