Before choosing a skincare product, it is essential to understand why the skin reacts in this way. The appearance of blackheads or open comedones can indicate a deeper imbalance linked to sebum production, hormones, your skincare routine, lifestyle or the environment.
Excess sebum: whilst the sebaceous glands produce sebum to lubricate and protect the skin, they can sometimes produce too much, causing sebum to build up in the pores. When it mixes with dead skin cells (or keratin debris), it forms plugs in the dilated pilosebaceous ducts, known as open comedones (1). These open comedones reveal a central black opening: blackheads. Not to be confused with spots, enlarged pores, which are tiny openings on the skin’s surface, or sebaceous filaments, which form yellowish or translucent irregularities on the T-zone (forehead, nose, chin). Combination to oily skin naturally produces more sebum on the face and is therefore more prone to blackheads. Furthermore, genetic factors may explain why some people have more active sebaceous glands and are more prone to blackheads.
An accumulation of dead skin cells: During the skin’s renewal process, dead skin cells that do not shed properly and accumulate on the skin tend to mix with sebum and block the pores, creating an environment conducive to the proliferation of bacteria, which leads to inflammation. This build-up, known as hyperkeratinisation, can occur even with normal sebum production (2).
Bacterial proliferation: if bacteria such as Propionibacterium acnes (or Cutibacterium acnes) develop in blocked pores, they can multiply, contribute to the blockage of the pores involved in the formation of blackheads, and ultimately trigger inflammation that can transform the blackhead into a red spot or pustule (2).
Surface oxidation: the build-up of sebum and dead skin cells, trapped inside the open pore, is exposed to the air, causing the substances to oxidise and, consequently, resulting in the characteristic black colour.
Hormonal imbalance: puberty, pregnancy, the menstrual cycle, stopping or changing contraception, or polycystic ovary syndrome (PCOS) can increase sebum production, which is a key factor in the formation of blackheads.
A polluted environment: fine particles of dust and pollution in the air can become lodged in the pores and mix with sebum, thereby creating blockages.
An unbalanced lifestyle: stress, smoking, and a lack of physical activity and sleep can affect hormones and the skin’s repair mechanisms. Similarly, a diet high in fast-acting sugars and saturated fats can lead to increased sebum production and skin inflammation (3).
An unsuitable skincare routine: over-cleansing with irritating active ingredients can disrupt the protective barrier, prompting the skin to defend itself by increasing sebum production. Conversely, insufficient cleansing is not enough to remove impurities accumulated in the pores, which promotes the formation of blackheads. Furthermore, occlusive make-up and comedogenic products can prevent the skin from breathing properly and lead to blocked pores.
