Q&A: Falk G. Bechara, MD, on Long-Term Tunnel Control and Structural Damage in HS

Tunnels are among the most burdensome manifestations of hidradenitis suppurativa (HS), contributing to recurrent drainage, pain, odor, inflammation, and permanent structural changes. Although surgery remains an important component of care for patients with established structural damage, emerging long-term data are providing greater insight into what medical therapy may be able to achieve—and where its limitations remain.

At the 2026 European Academy of Dermatology and Venereology (EADV) Congress in Vienna, Austria, new long-term analyses examined tunnel outcomes in patients with HS, including the durability of drainage control and exploratory changes in total tunnel burden.

In an interview with Dermatology Times, Falk G. Bechara, MD, discussed what the findings could mean for clinical practice, why surgery and medical therapy should be viewed as complementary rather than competing strategies, and the unanswered questions surrounding early vs long-standing tunnels.

Dermatology Times:

Why are tunnels such an important treatment target in hidradenitis suppurativa?

Bechara:

For the patient, the tunnel is one of the most important sources of inflammation. It is the tunnel that is oozing and draining and where the smell comes from. When it is inflamed, it is very often what causes the flare and the pain for the patient. For them, the tunnel can be one of the most bothersome symptoms.

Tunnels are also not necessarily stable in terms of their inflammatory activity. They flare. The structural damage stays in most cases, but the inflammation within that cavity can come and go. Once it flares, it can be extremely painful for the patient, and it makes the disease visible because you have stains, blood, or pus on clothing. Other people may be able to see it.

For us as physicians, tunnels are also important because they are one of the clearest signs of structural damage. A nodule may wax and wane, and the inflammation associated with a tunnel can wax and wane, but the underlying damage and overlying scars may remain.

If we approach our patients holistically and our goal is to bring them toward complete disease control, we have to understand that in many cases we may ultimately need to remove that structural damage surgically. Tunnels therefore have high importance both for patients and physicians.

Dermatology Times:

How do you approach conversations about surgery with patients who have tunnels or other structural damage?

Bechara:

It depends on the patient. If you have someone who has never had surgery, that is a different conversation from a patient who previously underwent inadequate or poorly performed surgery.

Very often, patients who have had a bad surgical experience are already afraid of surgery. They may refuse any further surgery because they tell you, “I had such a bad experience before. I don’t want that again.” In those situations, it is much harder to regain trust.

You may first put that patient on an effective medical treatment and then, several months later, discuss surgery again—not necessarily to convince them, but to explain what remains after medical treatment and what may still need to be removed.

The conversation should also be patient-centered. You have to ask, “What is your treatment goal?” Some patients will tell you their goal is simply to be pain-free and have no more drainage. You may be able to achieve that without surgery. But if the goal is to remove the remaining structural disease, apart from a surgical scar, then you have to explain that we may need a combination approach.

Importantly, I never see surgery as an opponent to medical treatment. It is a partnership. Sometimes we think in terms of either biologics or medications or surgery, but they have to come together to provide the maximum benefit for the patient.

Dermatology Times:

What were the main takeaways from the tunnel research presented at EADV?

Bechara:

There are 2 different aspects.

The first is what happens to drainage, or the activity of tunnels, over time. Imagine a patient who does not want surgery or does not have access to surgery and has draining tunnels. Our goal cannot just be a sprint. We need a marathon. We need long-term control of the drainage.

What was interesting in the work we conducted was that when we looked at the effect on tunnel drainage, we saw that drainage control could be stabilized over 3 years.

That is a long period of time, and it is exactly what the patient wants. It is not just short-term success. If a patient responds with a reduction in drainage, we can now say that this response may be maintained over a period of at least 3 years. That is a very important message.

The second part is more exploratory and somewhat controversial.

Normally, when we look at clinical outcome measures, we primarily evaluate draining tunnels. We ask whether a tunnel is draining or not. What had not really been done before was looking at the total tunnel count, independently of whether those tunnels were actively draining.

The traditional philosophy is that a tunnel can only be completely removed or closed if you excise it. For the first time, we looked at 1-year data examining total tunnel counts.

We were extremely surprised to see that after 1 year, approximately 30% of patients had no detectable tunnels.

But I want to be very cautious about what that means. I do not want the message to be that medical treatment healed the tunnels. It could be that the tunnels became so reduced in diameter that we could no longer clearly identify or count them. But even that would be meaningful for the patient.

We do not yet know exactly what this finding means. It could potentially be an indirect sign that medical treatment is reducing tissue damage, but I would be very cautious with that interpretation. This is the first time we have looked at this in this way.

One finding is much clearer: We can control drainage over the long term. The other is exploratory. We do not yet know what to make of it, but we can say that something appears to be happening to the structure.

Dermatology Times:

What additional research is needed to understand whether medical therapy is actually changing the structure of tunnels?

Bechara:

It would be very interesting to confirm these findings using objective measurements, such as ultrasound or MRI.

Right now, much of this assessment is based on palpation and inspection. If we could support those findings with objective imaging, we could better determine whether a tunnel is truly closing or changing structurally.

Then there is the question of durability. Is what we are seeing after 1 year a temporary situation, or is it something that remains stable over 2, 3, or 4 years?

I personally think timing may also matter. If you attack a tunnel very early, when it is not yet epithelialized and is still an initial cavity filled with neutrophils and pus, there might be a chance to close it.

But I think we have to differentiate those early lesions from long-standing tunnels. Unfortunately, we do not yet have the data to do that because we have not evaluated how long each tunnel was present before treatment.

That would be very interesting to study. My clinical experience suggests that long-standing tunnels, particularly those associated with fibrosis and hypertrophic or rope-like scarring, are unlikely to close completely with medical therapy alone.

Dermatology Times:

Does that raise the possibility that treating HS earlier could help prevent some permanent structural damage?

Bechara:

That is certainly an important question to investigate. We need to distinguish between early inflammatory lesions and tunnels that have been present for a long time and have developed significant fibrosis.

The possibility that an early tunnel could behave differently from an established, fibrotic tunnel is something we need to examine more closely. At this point, we do not have the data to say definitively that early medical intervention will close those tunnels, but it is an important area for future research.

Dermatology Times:

What have we learned about the safety of long-term biologic treatment in HS?

Bechara:

We are very lucky that, at least with the labeled biologics we have at the moment, we do not appear to see new HS-specific safety profiles.

These drugs have been used in other indications, depending on the molecule, for many years. We have a substantial amount of experience with them, and there does not appear to be a new safety issue that is specific to HS.

What I am personally very interested in now is safety not only with biologic monotherapy, but also when biologics are combined with surgery.

We have data for adalimumab, including randomized controlled data evaluating adalimumab in combination with surgery. I hope we will also obtain more data for other molecules.

We are working on studies evaluating surgery in combination with biologics because we want to answer a very practical question: Is it safe not to stop the biologic? Can we continue biologic treatment and perform the surgery without interruption? That is an important question as we move toward more integrated HS care.

Dermatology Times:

After working in HS for approximately 25 years, what excites you most about where the field is heading?

Bechara:

To see what has happened over the last 5 to 10 years is amazing.

It is not only here at EADV; you see it at the American Academy of Dermatology meeting and elsewhere. HS has become a major focus of research. The pipeline is full. People are caring about the disease, and that means they are caring about patients who have been suffering so much.

There is now a huge scientific effort. Studies are ongoing, awareness is rising, and people are talking about the disease.

Five or 10 years ago, it was more common to take molecules that had been developed for other indications and investigate them in HS. Now, for the first time, we are increasingly trying to identify targets based specifically on the pathophysiology of HS.

We are talking about fibroblasts. We are thinking about fibrosis because there is so much scarring and inflammation in this disease. That is great to see.

The patients have always been there. We simply did not care for them adequately enough. As physicians change their mindset and recognize HS as one of the major inflammatory skin diseases, I think we will continue to see the field move forward.

References

1. UCB. UCB announces new data at EADV 2026 supporting earlier use of BIMZELX® (bimekizumab) for treating hidradenitis suppurativa. Published September 30, 2026. Accessed October 9, 2026. UCB
2. UCB. BIMZELX® (bimekizumab-bkzx) data in hidradenitis suppurativa showed improvements in pain and resolution of draining tunnels sustained to three years. Published October 31, 2025. Accessed October 9, 2026. UCB