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Hidradenitis suppurativa: What Is It?

WoundCon Faculty
April 4, 2024

Editor's Note: In this interview, Hadar Lev-Tov, MD, MAS discusses what Hidradenitis suppurativa is and relevant questions in relation to his WoundCon Spring 2024 session titled, Hidradenitis Suppurativa and Wounds: Exploring the Unexplored.


Hi everyone, my name is Hadar Lev-Tov, MD, I'm an associate professor of dermatology. I work at the University of Miami in the department of dermatology and cutaneous surgery. I'm also the president-elect of the HS Foundation, which is the largest non-profit that is advocating for a disease called Hidradenitis suppurativa, or HS for short.

What is Hidradenitis suppurativa?

That is a very good question. And it's somewhat mysterious, right? The name Hidradenitis suppurativa, it sounds like a strange name in Latin. And it's very scary for patients as well when they hear it the first time. And so, we called it, for short, HS.

You may hear in more European literature it's also referred to as acne inversa, but really the disease is better yet defined clinically based on what we see, not necessarily about what's causing it. What we see are these lesions that occur in common locations and are recurrent. And so, I like to call these the 3 T's of HS. The typical lesions, the typical location, and the patient comes usually with a typical story. So, what are those lesions? HS presents with abscesses, nodules, tunnels, which are very familiar to us in the wound healing arena, because these are very analogous to tunneling wounds that we commonly see in practice.

What are those locations? The locations are the skin folds. Commonly the armpits (the axilla), the groin, and in females under the breast, as well as the buttocks area. So as you can imagine these are lesions that are painful, they drain a lot, sometimes patients feel like they smell bad, and so this is really translating to the immense morbidity this disease has for patients' quality of life.

So, we cover typical lesions and typical locations. Now, what is that typical story? Well, the typical story is a story of the purpose. And the textbook may say that the patient had more than 2 lesions in a span of 6 months, but really what you want to get a sense from the patient is how often this is happening. And if this is a recurrent story, meaning they get an abscess, and then it goes away but then a month later they get another abscess, or maybe they get a nodule that's very painful and then it kind of goes away. Somebody gave them antibiotics and it helps. But then 6 months later they get another one. This time it doesn't go away, and it ruptures and then becomes this tunneling wound that would just never stop draining. Those stories of recurrence of a long term process is what really differentiates a HS, from the main differential diagnosis, perhaps, which is just a random infection.

Now, you've got a random abscess that happens to be in the armpit, and that can happen, and that's fine. It doesn't mean that the patient has HS, but you really want to speak to the patient. And sometimes if you're clever enough, the skin may tell you a story because if you look at the right areas, you may see signs of older disease. And so those are the 3 T's that help you to understand what HS is on the skin, the typical lesions, the typical locations, and a typical story.

Can Hidradenitis suppurativa present with sinus tracts?

Yes, absolutely. So, first of all, let's put the terminology in order because there are 3 terms that are usually confused: sinus tracts, fistulas, and tunnels. They all mean the same thing when it comes to HS. So, if you're a patient listening to this or you are a health care provider, I'm going to refer to tunnels, but I mean all of the above.

And really what these tunnels are, are a structure that goes from the skin, burrows a hole very much like a tunnel, and goes into the dermis, into the deeper layer of the skin. Now it may end up on the other side of the skin. It may just be a blunted end, so like a dead end tunnel. It may, in rare cases, actually connect to a different organ, or different hollow space in the body, let's say the rectum, for example. And then maybe the better terminology is fistula.

But the idea is that you have a space, kind of like a tunnel, that goes into the dermis. Now, in reality these tunnels often can connect. And so, you may have a system of tunnels. One of my colleagues referred to these as the “ant farms” you can see sometimes when we were kids, we played. And so, it's easy to imagine this. I tell my patients a lot of time, this turns into almost a cave. So, you can imagine a large space that kind of expands. And what happens is these tunnels, they keep producing fluid, exudate, pus sometimes, and they are very, can be very painful and produce a lot of drainage.

And it's really strange, you can look at an opening of a tunnel that's maybe 4 millimeters in width, and it goes deep, but it produces drainage to us wound healing experts, you would look at this and say, “wow, this drains like a good size venous leg ulcer.” And that has a good implication for us to think about when we think about choosing the right dressing and the right wound care. So, tunnels also can be chronic, meaning they're not going to heal and often require surgery. A lot of times medications are just not good enough.

And so, when you see a patient with a tunnel, you should know one thing, it's not going to go away. They are going to be more chronically influenced by this disease. They need a care of a medical team, hopefully led by a dermatologist, and they need good medical care above all.

And so, tunnels are these structures that are part of HS, but they are also a marker of disease severity. And so, patients with tunnels, usually we will classify them as moderate or severe, depending on the extent of these tunnels.

How is this condition related to autoimmune disorders?

That's actually a common question that patients ask me a lot, and I want to be clear. We don't have evidence that HS is an autoimmune disease, because to define an autoimmune disease, you have to have the immune system attacking your own body. That means that you have to identify the actual antibody attacking the actual antigen, and when you identify the kind of antibody in the target, then you can really call this an autoimmune disease.

I would say that HS is autoinflammatory, meaning that the immune system is acting against your own body, but it does so by producing massive inflammation. There's some early evidence that maybe there's some antibodies that are HS specific, but I think we're far from a clear picture here. So, in short while HS may be related to autoimmune diseases, it is not clearly defined as such, and I think the better term is auto inflammatory. Your own immune system is starting to attack your own skin and create problems. Why is it doing this? What is it attacking? Still don’t know.

When treating Hidradenitis suppurativa, which are the best antibiotics for treatment? Any topical creams?

Well, that's a great question, and it eludes to the entire treatment of HS. So one thing I want to say is that probably when you see the patient in the wound center, the best thing you can do for them is refer them to a dermatologist, because this is a disease that is well known in dermatology.

Dermatologists care for HS for years and years and we have good experience and the dermatologist will probably be up to speed on all the current treatment. And I don't even know when this video is going to be released, but there's a good chance there's a new medication just about to be approved for HS because we have a slew of clinical trials and medical interventions.

And so, by the same token, the dermatologist will do very well for patients with wound problems to send to the Wound Center, especially patients with HS who have a lot of drainage and such. And so, we have to place the patients in the right health care system channel so they can navigate it and get to the right place. Now, about antibiotics, they are part, only part of the medical care that we use in HS. Antibiotics can be prescribed as systemic antibiotics by pills or even by vein, but they can also be topical antibiotics. And those have proven to be effective, mostly in the mild to moderate disease.

So, for example, the medication doxycycline or the group of medications in the tetracycline family has been shown to be pretty effective. Mostly in the mild to moderate category, patients with mostly nodules and random abscesses, when you get to tunnels, they may not help so much.

Another combination of medication that is used often is called clindamycin and rifampin used in combination. Some folks more recently may just use clindamycin alone and that seemed to work fairly well. Those oral antibiotics are effective, but like any antibiotic, you can't keep the patients on them forever. And so eventually, we have to find an alternative to that.

And there are other systemic therapies that are available. For the topical category, there is a medication called clindamycin that comes in the form of a lotion or solution, a topical application. There is some evidence that it can help, and we know in clinic that it works pretty well for the milder cases. More anecdotally, there have been reports of a cream, a keratolytic called resorcinol. It is not available commercially. in the US to my knowledge, it may need to be compounded, but some folks have used it with success. We, our group recently published on using an off-label medication called clascoterone. That medication has been approved for acne, but we have used it successfully on people with mild disease. So, you know, they get some nodules. They may be even on antibiotics, for example, but they still get some nodules, especially females around that time of the month when they're about to get their menstrual cycle, you can help control these flares by using clascoterone as our anecdotal series reported.

And then finally the last antibiotic mentioned that is really the antibiotic that is given by vein and there's a growing body of evidence to its use, so I'll mention it here and that is called ertapenem. Ertapenem is a drug again that's given by vein.

The common course is about 6 weeks. So, the patient will have to get some kind of a pick line or some kind of an IV line that can stay more durably for about 6 weeks. And then they'll get the medication daily. This medication is really strong. We reserve it to very severe cases. And I like to say that ertapenem is a bridge. It's a rescue therapy that is a bridge to other more long -term therapy. And I want to mention that all these antibiotics and creams that I mentioned are all off-label use. At this moment when we record this, there are only 2 FDA approved on labeled treatment for HS, and those are in the biologics category. So, none of the antibiotics are really on label for treatment of HS.

About the Speaker

Hadar Lev-Tov is an Associate Professor at the Department of Dermatology and Cutaneous Surgery at the University of Miami Miller school of Medicine. He is a Board-certified dermatologist with significant interest in wound healing and medical dermatology. His work is supported in part by a career development award from the Dermatology Foundation, the National Institutes of Health, and industry.

Dr. Lev-Tov completed his residency in Dermatology at Albert Einstein College of Medicine in New York City after completing a research post-doctoral training at UC Davis where he also earned his Master's in clinical research. Dr. Lev-Tov is the director of the wound healing fellowship at the University of Miami, serves as the President Elect for the HS Foundation board of directors (, is the founding program chair for the Integrative Dermatology Symposium ( and is the cofounder of the dermatology-focused educational service Learnskin (

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, HMP Global, its affiliates, or subsidiary companies.