Acne is caused when pores within the skin become blocked, causing inflammation and irritation and the formation of pimples, pustules, or nodules. Sebaceous glands, attached to hair follicles, produce sebum that naturally lubricates the hair and skin. But sometimes, the glands can create too much sebum, which can result in the formation of spots and blemishes, as well as the appearance of oiliness on the skin surface.

Comedonal acne is superficial and mild, presenting in the surface layer of the skin, the epidermis, in the form of white or blackheads. The accumulation of oil, dead skin cells and debris within pores creates a suitable environment for the proliferation of acne-causing bacteria (P.acnes) which triggers the body's immune response. White blood cells then invade the area, forming pimples and pustules, known as whiteheads.

In more severe cases of inflammation and infection, nodules and cysts may develop in the deeper layers of the skin, the dermis. This acne type is much more challenging to treat and can result in scarring and post inflammatory hyperpigmentation in darker skin tones.

Hormones, including testosterone and progesterone, can also play a role in the formation of acne, as they can overstimulate the sebaceous glands, as well as some cosmetic products (comedogenic), medications, smoking and diet.

Blue light is a clinically proven, effective and non-invasive treatment for acne as it stops the proliferation of the P.acnes bacterial cells. Naturally occurring photosensitisers within acne-causing bacteria (P.acnes) absorb the specific wavelength of 415nm blue light, causing cell destruction.