Cystic acne: what it is, causes and treatment

Cystic acne is the most severe form of acne: large, sore lumps that sit deep under the skin and often leave scars. It needs a doctor, and this guide explains why, what causes it, and what treatments a dermatologist can offer. It is part of Skinli's guide to the types of acne.

Skinli is an education site and is not a doctor. If you have deep, painful lumps now, the most useful step is to book an appointment with a doctor or dermatologist. The rest of this page will help you understand what they say.

What cystic acne is

Acne ranges from small clogged pores to deep lumps. The deep end has two kinds of lump, and the American Academy of Dermatology (AAD) explains the difference:

• A nodule is a hard lump deep in the skin with no pus inside.
• A cyst is a deep lump that contains pus, so it feels softer than a nodule.

Both form the same way. The AAD says that when a pore fills with enough oil, dead skin cells and bacteria to cause swelling that goes deep into the skin, a nodule or cyst develops. Because they sit so deep, they feel tender or painful. The AAD's isotretinoin page says these lumps can be the size of a pencil eraser or larger.

People use several names for this pattern. NIAMS, part of the US National Institutes of Health, calls it severe nodular acne and says it is sometimes called cystic acne. MedlinePlus calls it nodulocystic acne. The UK NICE guideline uses nodulo-cystic acne. All of these describe the same thing: acne with deep nodules, cysts, or both.

How serious it is

Cystic acne sits at the top of every severity scale. The NICE guideline places anyone with 3 or more nodules in its moderate to severe band. It tells doctors to refer people with nodulo-cystic acne to a team led by a consultant dermatologist, a hospital skin specialist, rather than treat it alone.

The AAD describes severe acne as breakouts that often extend deep into the skin, tend to be painful, and often leave scars as they clear. It says severe acne can cover the face, chest and back, and can also appear along the jawline and neck, and sometimes on the buttocks.

What causes it

The pore-level cause is the same as for any acne: oil, dead skin cells and bacteria in a blocked pore. What makes some people get deep lumps is less clear, but the sources name a few risk factors:

• Family history. The AAD says your risk is higher if a parent or another close blood relative had deep, painful pimples, or severe acne that left scars.
• Hormones. NIAMS says a rise in androgens, often called male sex hormones, enlarges the oil glands and can lead to acne. The AAD says deep, tender acne on the lower face, jawline or neck in women can respond to hormone treatment.
• Medicines. NIAMS names medicines that contain hormones, corticosteroids and lithium. NICE says anabolic steroids that people take on their own can contribute to acne.

Skinli's guide to hormonal acne vs regular acne covers the hormone pattern in more depth. The broader list of triggers is in what causes acne.

Why store products cannot clear it

The AAD is direct about this: you cannot clear severe acne with acne treatment bought at a store. Its overview page explains why. Deep, painful acne needs treatment that works on four causes at once: clogged pores, bacteria, swelling and extra oil. Getting a treatment that does all four takes a dermatologist.

The AAD recommends store-bought benzoyl peroxide, salicylic acid and adapalene for blackheads, whiteheads and ordinary pimples. A dermatologist may keep one of them in your plan, next to the stronger treatment that deep acne needs.

What a dermatologist can offer

The AAD lists the main options for severe acne, and the 2024 US acne guideline in the Journal of the American Academy of Dermatology backs them:

Treatment	What the sources say
Antibiotic taken by mouth, plus a medicine applied to the skin	The AAD says this is often the first treatment for severe acne. The antibiotic calms redness and swelling, and the skin medicine works on bacteria and clogged pores.
Isotretinoin	A prescription pill that the AAD says works on all four causes. It says 85 percent of patients see permanent clearing after one course, which takes four to five months. The 2024 guideline strongly recommends it for acne that is severe, scarring, or not helped by other treatment.
Birth control pill (women only)	The AAD says it can be an effective part of a plan, often with an antibiotic or spironolactone.
Spironolactone (women only)	The AAD says it reduces extra oil and can treat severe acne in women.
Steroid injection into one cyst	The AAD says it flattens most nodules or cysts within 48 to 72 hours and lowers the risk of scars. It is used for one painful lump at a time. The 2024 guideline lists these injections for larger acne lesions as good practice.
Incision and drainage	A dermatologist opens a large cyst with a sterile needle or blade and removes what is inside.

Isotretinoin has strict rules. The AAD says patients in the US must enroll in a monitoring program run under the FDA, called iPLEDGE, which is designed to prevent pregnancy during treatment. A prescription covers 30 days, and a follow-up visit is needed each month. The AAD warns that buying isotretinoin online without a prescription puts your health at serious risk.

The AAD says it can take two to three months to see improvement from treatment for severe acne. After the skin clears, most people need ongoing treatment to keep it clear.

What to do while you wait for an appointment

A few steps help, and they are all about avoiding harm:

• Do not squeeze or drain a cyst. The AAD says draining a cyst or nodule at home carries a high risk of infection, and squeezing pushes material deeper, which increases swelling and the chance of scars.
• Use ice for pain. The AAD says ice reduces swelling in painful nodules and cysts.
• Keep your routine gentle. A mild cleanser, an oil-free moisturizer and sunscreen do no harm while you wait. The complete acne skincare routine lists the steps.
• Keep taking anything a doctor prescribed. Skinli's rule is to never stop a prescribed treatment without talking to the doctor who prescribed it.

Other deep lumps that are not acne

Some deep, painful lumps look like cystic acne but are a different condition:

• A boil. The NHS describes a boil as a hard, painful lump that fills with pus. It says to ask for an urgent appointment if a boil is on your face, if the skin around it is hot, painful and swollen, or if you feel hot, cold or shivery.
• Hidradenitis suppurativa. The AAD says this long-term condition causes pimple-like bumps or deep, acne-like cysts where skin touches skin, such as the armpits, groin, buttocks and upper thighs.
• Fungal acne. A 2025 review in the Journal of Fungi says fungal acne, a yeast infection of the hair follicles, does not produce nodules or cysts. Its bumps are small, itchy and all look alike. See fungal acne.

A dermatologist can tell these apart by looking at the skin and, when needed, testing it.

Scars, mood, and why early treatment matters

The AAD says the sooner treatment starts, the fewer permanent scars you will have. The NICE guideline says the risk of scarring rises with how severe acne is and how long it lasts. How to get rid of acne scars explains what can help true scars, and dark marks after pimples covers the flat marks that fade on their own.

Severe acne also affects how people feel. The AAD says many studies link acne with low self-esteem, depression and anxiety, and that treatment can improve mood as well as skin. The NICE guideline says acne of any severity that causes lasting distress is a reason to consider referral to a dermatologist. The NHS says to see a GP if acne is affecting your mental health.

When to see a doctor

See a doctor or dermatologist if you have any deep, painful lump that you think is acne. That is the point where the AAD, NICE and the NHS all agree that store-bought care is not enough. Ask for an urgent appointment if a painful lump on your face comes with hot, swollen skin or a fever, following the NHS advice on boils.

If you are not sure whether your spots are deep enough to count, Skinli's photo check flags signs that need a doctor, and its plan tells you what to say at the appointment.