The science of nodular acne: Understanding this form of acne

For a variety of reasons, this is one of the most difficult types of acne to treat.

Written by
Rachael Belfield
Medically reviewed by
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Have you ever run a finger over your skin and noticed it's without a "head" and instead, is a hard, painful bump under your skin? This might be nodular acne.

Nodular acne breakouts are normal and nothing to be worried about: they happen to a range of people, at all ages of life and to all different skin types. But, for a variety of reasons, they're one of the most difficult types of acne to treat.

So, knowing how to treat nodular acne causes, and keeping it away, is vital for clear, scar-free skin.

What is nodular acne?

Nodular acne is, according to a 2012 study in the American Journal of Clinical Dermatology, characterised by "...nodules, intense erythema, inflammation, cysts, and scarring" [1].

They're sometimes referred to as blind pimples. These zits are particularly sinister because they start deep under the skin's surface as a clogged pore, which progresses into a hard, sore bump.

What does an acne nodule look like?

Nodular acne often turns red, but sometimes it will stay the same colour as your skin, making it difficult to determine what it is. The most obvious characteristic of nodular acne is that it feels like a knot, or hard lump, under your skin.

And, to make it even nastier, these pimples don’t usually have a whitehead or blackhead at the centre. This is because the clogged pore is too deep under the skin to produce a pimple "head" — they are not filled with fluid like acne vulgaris.

Being deep under the skin means they are often sore and sensitive: being trapped causes them to become inflamed [2].

Nodular acne lives deep under the dermis, in the same place where our collagen is. Unfortunately, this means scarring can often come with these nasty little zits, as the inflammation caused by the bump damages the collagen.

What causes acne nodules?

Nodular acne is caused by the same things that cause acne vulgaris, or regular acne. Here is a non-exhaustive list of common nodular acne causes.


Those pesky genes, which we have no control over, might be one of the reasons you're getting acne nodules. If you have a family history of nodular acne, chances are that gift will be passed onto you, too.

Dead skin cells

When left on the face, dead skin cells can mix with sebum and sit under the skin's surface, clogging the pore.


Nodular acne can form when a type of bacteria that lives on the skin (P. acnes) gets trapped deep inside the clogged pore, leading to an infection that affects the deeper layers of the skin.

Androgen hormones

Fluctuations in the androgen hormones are specifically linked to nodular outbreaks, simply because these 'male' hormones increase oil from our sebaceous glands, building up and clogging our pores. Teenagers are the most susceptible to these fluctuations as they move through puberty.


Certain drugs, including corticosteroids, can worsen nodular acne [3].


An increase in stress and anxiety in your life can cause your body to produce stress hormones, particularly cortisol, which in turn increases sebum production and leads to inflammatory acne [4].

Nodular acne vs cystic acne

It can be easy to incorrectly identify nodular acne as cystic acne. They are similar, but there are some crucial differences between these types of acne.

Both cystic and nodular acne form under the skin and form painful bumps. Both are caused by bacteria being present on the skin and clogging a pore. Both lead to swelling and inflammation and, often, scarring.

But cystic acne causes cysts, not nodules, under the skin. Cysts are softer than nodules because they are filled with pus, a fluid; they look like angry, red boils. Nodular acne is harder, like a knot, and it does not contain any fluid [5].

Cystic acne lumps are softer than nodules. Nodules are firmer, very painful and feel like knots under your skin. Some people have both cysts and nodules, which would be classified as severe acne.

How long does a nodule pimple last?

If nodular acne is overstaying it's welcome on your face, you're probably wondering when it's going to get the hint and leave. Typically, nodules will minimise and disappear within 2-4 weeks with treatment. If left untreated, acne nodules can stick around for much longer, sometimes months.

This is because, unlike whiteheads, blackheads or pustules, nodular acne is deep under the skin, meaning it will be harder to get out.

Scarring is much more likely to occur if nodules are left untreated.

Can you drain or pop nodular acne?

NO! And we really, really mean it! Absolutely not!

You cannot drain or pop acne nodules because they are too deep under the skin. If you poke or prod at nodular acne, you will cause more scarring and pain for your poor, inflamed skin. This is because they are not filled with fluid like regular pimples.

The lump you're running your finger over is infected, inflamed skin that needs some careful TLC. It might be tempting to try and pop it, but you will open yourself up to inflammation, infection and acne scarring.

If you have a particularly painful nodule, your dermatologist may use a procedure called incision and drainage, which involves using a sterile blade to open the pimple and remove what's inside [6]. A dermatologist can do this safely and without the risk of scarring. Never do this at home.

How do I treat nodular acne?

Luckily, there are a number of effective and safe ways to treat nodular acne. Following these treatment options properly will not only remove nodules but also minimise the risk of scarring.

Oral medications

  • Hormonal treatments: There is a wealth of clinical evidence to suggest that hormone therapies are highly effective for treating nodular acne [7]. Taking combined birth control pills, under the guidance of your healthcare provider or dermatologist, can be a good place to start, especially if your nodular acne is persistent.
  • Oral antibiotics: An oral antibiotic should be used only if you are experiencing severe acne nodules. Oral antibiotics are safe and effective.

Topical medications

  • Retinoids: Prescription retinoids are another type of vitamin A and are particularly good for reducing scarring and stopping the formation of acne.
  • AHAs and BHAs: These handy acids help to treat acne by penetrating deep into the skin and clearing away acne-causing bacteria. Software's AHA/BHA Pimple Patches harness the power of AHAs and BHAs to kill off bacteria deep within the follicle, which helps contain the spread and limit new spots from popping up.
  • Salicylic acid: Salicylic acid gently exfoliates and removes dead skin cells, therefore helping to unclog pores and minimising the risk of further inflammation. Software's Salicylic Acid Foaming Wash unclogs debris and trapped oils in the pores and helps reduce the formation of acne.

Other treatments

  • Apple cider vinegar: ACV can balance the skin's pH levels, exfoliates the skin cells and can help manage nodular acne thanks to its antibacterial and anti-microbial properties.
  • Chemical peels: A chemical peel will remove the dead skin around hair follicles and reduce oil production.
  • Dermatological removal: Once again, this must be done by a dermatologist.

Does nodular acne leave scars?

Unfortunately, nodular acne is more likely to cause scarring than acne vulgaris. Due to it being embedded under the skin, severe nodular acne can leave acne scars, especially if left untreated.

How can I prevent nodular acne?

To prevent nodular acne, you need to look after your skin with careful consideration. Using an exfoliating wash 2-3 times a week, like our Salicylic Acid Foaming Wash, will stand you in good stead in avoiding those nasty nodules.

Software also offers a personalised solution for all kinds of acne in the form of our prescription acne formula. Simply complete our online consult and an Australian health practitioner will create a formula based on your skin needs and goals with ingredients like prescription retinoids, niacinamide, hyaluronic acid and azelaic acid.

Not into the idea of a full regime just yet? You might want to browse our non-prescription range, which includes acne-banishing goodies like our 4-step Acne Kit. This is designed to target acne at all stages and repair your skin barrier for a clearer complexion.

Either way, Software is here to support you with a holistic approach to good skin.

Photo credit: Getty Images

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