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Image Source: Getty / Jena Ardell

Severe acne is more than just an inconvenience – it is stubborn, requires a dermatologist’s care, and can be extremely painful, leaving emotional and physical scars in its wake. Those who experience more extreme types of acne (from cystic acne to more serious immune responses) understand just how harrowing the process of identifying and treating these skin conditions can be. It’s more complicated than popping on a hydrocolloid patch and changing your pillowcase.

To get a better understanding of the different types out there, as well as severe acne treatment options, we tapped board-certified dermatologist Anthony Rossi, MD – a leading expert on sensitive skin at Memorial Sloan Kettering Cancer Center – to give us a rundown on the main forms, what causes them, and the most effective ways to treat them. But first, what is considered severe acne?

“Severe types have larger, inflamed cystic nodules that can be painful and result in pitted severe acne scars, as well as hyperpigmentation and dermal skin atrophy,” Dr. Rossi tells PS. Acne is extremely common – in fact, it’s the most common skin condition among teens, with up to 30 out of 100 teens experiencing moderate to severe forms of acne. While there are varying types of severe acne and many ways to treat them (more on that below), there are two main commandments, according to Dr. Rossi: “Do see a board-certified dermatologist, and don’t pick, pop, or squeeze.”

Acne Conglobata

What Is Acne Conglobata?

“This is part of a group of skin disorders called the follicular occlusion tetrad,” Dr. Rossi says, meaning acne conglobata has friends in low places – with a few other unwelcome skin conditions that form in similar ways. Acne conglobata, a severe type of nodulocystic acne, begins with blocked hair follicles that form clusters of comedones, which develop into pus-filled cysts. These nodule cysts then create a network of sores that can appear almost everywhere on the body: face, chest, back, shoulders, arms, thighs, and butt. The nodules are red and tender to the touch.

What Causes Acne Conglobata?

According to Dr. Rossi, acne conglobata can be caused by “hormones, genetic predisposition, and an inflammatory response to a bacteria known as propionibacterium acnes.” In layman’s terms, it often crops up the same way common acne (aka acne vulgaris) does. However, there are other possible causes, though they’re rare. “The ingestion of thyroid medication and exposure to halogenated aromatic hydrocarbons – a type of environmental pollutants – may also be implicated in acne conglobata, as well as androgen hormones and anabolic steroids,” Dr. Rossi says.

How to Treat Acne Conglobata

Because acne conglobata is known to result in scarring, you’ll want to get in touch with a dermatologist to get a treatment plan going ASAP. Luckily, the treatment is pretty straightforward. Dr. Rossi advises following a prescription of isotretinoin and systemic steroids.

Acne Fulminans

What Is Acne Fulminans?

Quick-onset severe acne that results in open sores on the face, chest, or back, acne fulminans is “a rare systemic disorder characterized by a presentation of nodules and cysts,” Dr. Rossi says. Though it appears like acne conglobata at first glance, acne fulminans can actually affect other organ systems as well, potentially resulting in anemia, an enlarged spleen, liver abnormalities, joint pains, and/or fevers. “SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) may also be a serious complication of acne fulminans,” Dr. Rossi says. SAPHO syndrome is a rare chronic inflammatory disorder.

What Causes Acne Fulminans?

The cause can be an increase in androgens in the body, an autoimmune complex disease, or a genetic predisposition.

How to Treat Acne Fulminans

It’s important to seek dermatologist treatment immediately, since acne fulminans can take several months and medications to get under control. “Acne fulminans requires treatment with systemic corticosteroids as well as anti-inflammatories, antibiotics, and oral isotretinoin,” Dr. Rossi says.

Nodulocystic Acne

What Is Nodulocystic Acne?

“This is a severe form of inflammatory acne and causes nodules and cysts that can be painful and lead to scarring,” Dr. Rossi says. They’re deeper, larger, and very uncomfortable. This can carry consequences beyond the physical as well. “It can cause decreased self-esteem and physical dissatisfaction, potentially causing people to become more withdrawn from social engagements.”

What Causes Nodulocystic Acne?

If skin care had a villain’s origin story, it might go something like this: Excess oil and/or dead skin cells block a pore, forming a comedone. Bacteria enter the chat, and the comedone turns to the dark side – becoming a very large, inflamed nodule. Sounds scary, we know, but why does this happen? As it turns out, nodulocystic acne is typically the byproduct of genetics, hormonal fluctuations (especially for those experiencing periods), and inflammation-causing bacteria.

How to Treat Nodulocystic Acne

If you suspect your breakout is nodulocystic acne, you’ll want to skip the over-the-counter products and make an appointment with a derm. “It usually requires oral retinoids such as isotretinoin to get under control, while steroid injections can help bring down individual lesions,” Dr. Rossi says. He adds that photodynamic therapy can be an option for those with sensitivity to isotretinoin.

Gram-Negative Folliculitis

What Is Gram-Negative Folliculitis?

“Gram-negative folliculitis is a bacterial infection of the hair follicle that looks and mimics acne, but the papules and pustules are centered around the hair follicle,” Dr. Rossi says, explaining that “gram-negative” refers to a type of bacteria. It resembles an acne-like rash of pustules (rather than papules or comedones) and occasionally penetrates the skin on a deeper level to form lesions similar to cysts.

What Causes Gram-Negative Folliculitis?

As mentioned above, gram-negative folliculitis is specifically caused by a family of bacteria that includes Pseudomonas, E. coli, Klebsiella, and Proteus. Oftentimes, patients with this infection will have tried traditional acne treatments (like acne-specific antibiotics) without success, in which case a bacterial test is the best route.

How to Treat Gram-Negative Folliculitis

“If suspected, the dermatologist can do a bacterial culture to detect the bacteria as well as see what antibiotics it is susceptible or resistant to,” Dr. Rossi says. Once gram-negative folliculitis is confirmed, it “can be treated with topical antibiotics and antibacterial washes, as well as oral antibiotics for more severe or widespread cases.”

– Additional reporting by Renee Rodriguez


Hannah Cassidy is a PS contributor.


Renee Rodriguez is a staff writer and social producer for PS. She writes across all verticals, but her main areas of expertise focus on fashion and beauty content with an emphasis on reviews and editor experiments. She also produces social content for the PS TikTok and Instagram accounts.