Different Types of Acne: A Dermatologist's Guide to Breakouts

When it comes to acne, there is no one singular type, cause, or treatment. 

From mild breakout to inflammatory acne, each type of acne looks and behaves differently — and responds to varying ingredients and treatments. As such, understanding what type you are experiencing may be the difference between finding a solution that works, or one that causes more long-term skin problems. 

In this article, we'll explore the six most common types of acne, how to differentiate between them, their causes, and suitable treatment options.

If you've landed here, chances are you have at least a base-level understanding of what acne is. But just in case, here's the quick explanation:

Acne vulgaris is a skin condition that results from hair follicles becoming clogged with sebum (oil) and dead skin cells. Bacteria can then multiply in the blocked pores, triggering inflammation.

Once the pore is clogged, it can develop into one of two types of acne:

• Inflammatory acne: includes papules, pustules, nodules, and cysts.

• Non-inflammatory acne: includes blackheads and whiteheads.

There are four factors linked to acne breakouts:

• Excess oil production

• Clogged pores

• Bacteria

• Inflammation

Want to learn more? Read our full article on What Causes Acne in Adults? 6 Triggers You Might Not Know About.

Whiteheads are one of the two non-inflammatory types of acne. They are closed comedones that remain sealed at the surface of the skin due to clogged pores — consisting of dead skin cells and oil — preventing the hair follicle from opening.

Unlike blackheads, which are known as open comedones, a whitehead occurs when the pore remains sealed, resulting in a white, raised bump. Because the dead skin and oil don't oxidise, they don't change colour.

Whiteheads generally appear as one or more of the following:

• White or yellow raised bumps

• Commonly found on the face, neck, back, and chest

• Minimal inflammation or redness

Whiteheads result from hair follicles and sebaceous glands becoming blocked and inflamed, with a few contributing factors:

• Excess sebum production

• Unusual formation of keratin — the protein responsible for your hair, skin, and nails

• An increase in acne-causing bacteria on the skin

Blackheads are another of the non-inflammatory types of acne. Like whiteheads, they occur when pores become clogged with oil, dead skin cells, and bacteria — resulting in raised bumps on the skin's surface.

Unlike whiteheads, however, blackheads are open comedones. This leaves the material inside the pore exposed to the environment, causing it to darken through oxidation. While many people assume a blackhead is dirt, it's actually this chemical reaction that causes the colour change.

• Small, raised or flat bumps that are black or dark grey

• Most commonly found on the nose, chin, and forehead (the oiliest parts of the skin)

• May also appear on the back, chest, shoulders, and ears

• Non-inflammatory — no pain, redness, or swelling

Blackheads are caused by the same things as whiteheads: excess oil production, dead skin cell buildup, bacteria, and hormones. You may be more prone to blackheads if you have enlarged pores or produce excess sebum.

• Salicylic Acid: Helps dissolve the bonds holding dead skin cells together, preventing pores from becoming blocked.

• Tea Tree Oil: A 2019 review found tea tree oil to be effective for mild to moderate acne, owing to its antioxidant, antimicrobial, and anti-inflammatory benefits.

• Azelaic Acid: Boasts antimicrobial and anti-inflammatory properties that encourage cell turnover to avoid pore blockages.

• Retinoids: Help normalise the skin cell shedding process, reducing pore blockages caused by excess sebum and irregular cell turnover.

Papules are one of the four inflammatory types of acne. They appear as raised, inflamed bumps on the skin, generally under 1cm in size. Papules don't contain pus — they are solid acne lesions consisting of bacteria, oil, and dead skin cells.

• Small, solid bumps that are red, brown, purple, or skin-toned, with no centre

• No larger than 1cm

• Swollen, red, and tender

• No visible pus

• Often appear in clusters

A comedone becomes a papule when excess sebum causes natural bacteria to overgrow, rupturing the pore and spreading bacteria into the surrounding skin tissue. The resulting redness and swelling is your body's immune response as it works to fight the infection.

Like other types of acne, papules can occur due to:

• Excess sebum production

• Increased androgen hormone activity

• Increased bacterial presence on the skin

Pustules are another of the inflammatory types of acne, characterised by small, raised bumps that contain pus or fluid. Most pustules begin as papules.

• Raised, red bump with a white or yellowish centre

• Painful and inflamed

• Commonly found on the face, chest, and back

When the immune system responds to a papule, it sends white blood cells to fight the bacterial overgrowth. The accumulation of those white blood cells is what forms the white or yellow head — otherwise known as pus.

Nodular acne is a more severe type of inflammatory acne that presents as hard, painful bumps deep under the skin. Due to how deep this type of acne forms, it requires a much more tailored and considered treatment plan than surface-level types of acne.

• Hard bumps deep within the skin

• Can be skin-toned or red

• No head (no pus)

• Painful, swollen, and red

• Won't respond to over-the-counter products

• Can cause significant scarring if not treated adequately

Nodules form when P. acnes bacteria becomes trapped in the pores along with excess oil and dead skin cells, causing infection deep under the skin and triggering an inflammatory response of swelling, redness, and tenderness.

Cystic acne is the most severe of all the types of acne. It presents as large, pus-filled cysts that form deep within the skin. Often mistaken for boils, cystic acne is red, painful, and requires a dermatologist's guidance to treat safely.

• Large, boil-like appearance

• Pus-filled, so softer to touch than nodules

• Painful, swollen, and red

• Relatively large in size

• Most commonly found on the face, but can also occur on the chest, neck, back, and arms

Like nodular acne, cystic acne occurs deep within the skin and can cause considerable pain and swelling. The key difference between the two types of acne is that cysts contain fluid (pus), whereas nodules are solid, hard lumps with no fluid.

Cystic acne occurs when bacteria, dead skin cells, and excess sebum become trapped in the pores, allowing bacteria to spread deep within the skin. As with pustules, the body's immune response creates the pus through the accumulation of white blood cells — but unlike pustules, this happens at a much deeper layer of the skin, which is why cystic acne is considered the most severe type.

Whether a pustule develops into a cyst can depend on:

• Whether the follicle wall ruptures

• How intensely the immune system responds

Inflammatory types of acne vary in severity. While some can be resolved with over-the-counter treatments and a consistent skincare routine, others require professional guidance. Regardless of the type, inflammatory acne with pus should never be popped — doing so can spread bacteria and worsen breakouts.

These types of acne can often be treated with over-the-counter or prescription products, which may include the following ingredients:

• Benzoyl Peroxide

• Salicylic Acid

• Retinoids

• Sulfur

However, with all forms of acne, whether mild or more severe, we always recommend seeking expert guidance from a skin professional before starting any new treatments or products. 

Due to their severity, these types of acne don't respond to standard over-the-counter treatments. It's essential to seek the guidance of a dermatologist or doctor who can create a tailored protocol for your needs. Treatment options may include:

• Prescription-strength salicylic acid, benzoyl peroxide, or retinoids

• Antibiotics

• Birth control pill

• Laser therapy

• Chemical peels