Types of Blemishes

Ever wondered how whiteheads and blackheads differ? Or how different types of blemishes respond to different treatments? We’ve covered it all with our comprehensive guide to understanding imperfections.


Milia are tiny white bumps that often appear in clusters around the nose, eyelids and cheeks. They are most common in newborns, but can make an appearance in adult life too. Often a result of skin trauma (burns, blisters etc.), or skin conditions such as rosacea and dandruff. People often mistake them for blemishes, but they are actually a build-up of the protein, keratin. They can be managed by a skincare regime incorporating AHAs, BHAs and retinoids.


Papules are inflamed lesions that appear as small, pink bumps on the skin. They can often be tender to the touch and are usually the first sign that a breakout is on the way.

When a pore becomes blocked with dead skin cells and excess sebum, blemish-causing bacteria (P. acnes) begin to thrive. This infection triggers an inflammatory response in the body, which is why papules are raised and slightly pink.


Pustules develop from papules. As levels of blemish-causing bacteria rise, white blood cells are sent to the site of the blemish to fight off infection. The aftermath of the 'bacteria vs white blood cell' battle is pus, a whitish substance made up of dead white blood cells, P. acnes and sebum. As such, pustules are topped with pockets of yellow or white pus and will usually be painful and red at the base. They are what most people refer to when they talk about a pimple.

Blackheads & Whiteheads

Also known as comedones, these types of blemish refer to a hair follicle that has become clogged with excess sebum and dead skin cells. If the blockage reaches the skin’s surface, the clogged up sebum becomes oxidised by the air and turns black or grey in colour. Dermatologists refer to it as an open comedone, but we know it as a blackhead.

If the blockage remains beneath the the skin, it is called a closed comedone or whitehead. Because oxygen cannot reach the built-up plug of sebum, oxidation cannot take place. This prevents the sebum from turning grey, allowing it to retain its natural white colour.

Both types of comedone are a non-inflammatory, so they should never be painful or swollen. But they can sometimes lead to inflammatory blemishes.

Nodules & Cysts

Nodules occur when a hair follicle wall ruptures within the dermis. This happens when a pore is clogged at its base. Because the infection is so deep, the rupture takes place under the skin rather than at the surface. This causes significant damage to the follicle, which leads to excessive inflammation and tenderness. Just like pustules, nodules can be filled with pus, but you will never see a whitehead as the infection is so deep.

When the swelling and inflammation of a nodule becomes so intense that it damages the healthy skin surrounding it and destroys the hair follicle, dermatologists refer to it as a cyst. This type of blemish is the most painful of them all and is extremely prone to scarring.

Both nodules and cysts can take several weeks or months to fully heal.

How do you treat different types of blemishes?

Blackheads, whiteheads, papules and pustules are often treated with specific skincare, which does not require a prescription. Salicylic acid is the gold-standard treatment for this type of blemish, as it can enter the hair follicle and break down clogged pores, preventing the formation of blemishes. If you’ve got mild to moderate blemishes, try Medik8 Blemish Control Pads. Use them once or twice a day, to keep skin clear and healthy.

For severely inflamed blemishes, like nodules and cysts, prescription medication may be required. Trained professionals can offer peels and facials that penetrate the skin at a much deeper level to target under-the-skin breakouts.

At Medik8, we offer Clarity Professional Skin Peel, a clarifying chemical peel that uses a blend of powerful exfoliating acids to effectively clear the skin of breakouts while preventing future blemishes. See the results on our before and afters page or find your nearest skincare centre here.

Living with acne is tough. That’s why we have a full topical solution dedicated to this concern at Medik8. Start your journey to clearer skin today.

Understanding the acne grading system

Dermatologists often grade acne using the Pillsbury Classification Scale. This is a numeric system, ranging from 1 to 4, that allows you to determine the severity of your blemishes.

Grade 1

The mildest form of acne. It consists mostly of comedones and pustules on the nose, forehead, cheeks and chin. Salicylic acid-based products will usually clear these problems.

Grade 2

Considered moderate acne. There will be a far greater number of comedones accompanied by papules and pustules. Occasionally, deeper inflamed lesions will also develop. Thorough exfoliation is required to keep this level of acne in check. If left untreated there is a high chance that it will progress to grade 3.

Grade 3

Considered a severe form. The main difference is the amount of inflammation present. Sore, red, swollen lesions tend to take over. Papules and pustules are developed in greater numbers and nodules are generally present. This type of acne is best treated through a combination of topical and oral therapies prescribed by a dermatologist.

Grade 4

The most severe form of acne. It is often referred to as nodulocystic or cystic acne. The skin will display a whole spectrum of blemishes such as comedones, papules, pustules and nodules with the addition of deep-seated cysts. Acne of this severity usually extends beyond the face and may affect the entire back, chest, shoulders and upper arms. Grade 4 acne should always be treated by a dermatologist as it is notoriously difficult to control and almost always requires powerful prescription medicine to keep it at bay.