Colleen Cotton, MD: Challenges in Diagnosing Pediatric Hidradenitis Suppurativa

Colleen Cotton, MD

Credit: Childrens National Hospital

In a recent Q&A interview with the HCPLive editorial team, Colleen Cotton, MD, spoke about some of the challenges in diagnosing pediatric hidradenitis suppurativa (HS) as well as current HS research.

Cotton is known for her work as Attending Physician for the Division of Dermatology at Children's National Hospital, as well as her work as Assistant Professor of Dermatology for the George Washington School of Medicine and Health Sciences.

The discussion covered much of what her upcoming presentation touches upon. Cotton will be presenting at the 8th annual Symposium on Hidradenitis Suppurativa Advances (SHSA) Conference on October 13 - 15, speaking on the topic of pediatric HS.

HCPLive: Why did you feel your presentation on pediatric HS for the upcoming SHSA conference was important to give to the attendees?

Cotton: I think it's particularly important in the context of HS to talk about pediatric HS, because initially, I think there's still this misconception that this is a condition that really starts to start to come around around age 20 - 25 or so. And what we've kind of realized is that the initial average was really kind of missing this bimodal peak of HS coming on in patients. And so really, that first peak occurs during adolescence.

Somewhere around at least 50% of patients, according to 1 study, started to develop their first signs and symptoms of HS in their adolescent years…I do feel like we're seeing a lot more in terms of patients with HS. I do think that incidence is increasing, and I think that education is needed in terms of helping people understand that not only is this also a pediatric disease, but this is something that can progress rather rapidly during that time period.

HCPLive: What are some of the current challenges in diagnosing pediatric HS? I know you mentioned that, for some, age is an element that affects diagnosis.

Cotton: In adults, there have been the classic statistics that a delay in diagnosis can be 7 to 10 years, which is crazy long, but also this suggests that a lot of these patients develop their initial symptoms in childhood. Some of the more recent studies on pediatric patients have shown that there is a delay in diagnosis that is closer to around 2 years or so. And I think one of the challenges there is I'm not convinced that's definitely a delay, since not all of these patients necessarily meet criteria for HS, with their very first flare of symptoms.

Do they just have folliculitis, and they had a particularly bad abscess related to that? Sometimes it can be very challenging to tell the difference between folliculitis and early HS. And in some cases, it doesn't necessarily matter in how you treat them initially, because those treatment strategies overlap quite a bit. But it is important to have that conversation with the family and say, ‘Look, I don't know exactly what this is going to look like chronically long-term, whether this is going to be a progressive disease, or whether this is a condition that we're going to be able to get a pretty good handle on.’

…For adults, we ask the screening question of ‘have you had a boil in one of these characteristic areas, 2 or more times in the last 6 months?’ Well, at the beginning of the disease, that may not be enough time in pediatric patients to see that recurrence. They may only be having an episode once every several months, once a year, if they're starting out kind of slow on that trajectory. So it may be a couple of yours before we can tell them ‘yes, this is definitely a recurrent problem.’

Something I see a lot also is when patients go to the emergency room and say get their first boil lanced, there's not necessarily a bacterial culture that's done. So when they come to me, and they say, ‘I've had two abscesses in my underarm, and they've had to drain them twice, and there's been no culture.’ Okay, what was that like a recurrent Mrsa infection? Is there a bacterial component here? Or is this the first sign of HS when you have no involvement in any other areas, and you've never had anything else like this? It can also be very challenging to make that diagnosis.

HCPLive: Are there any other notable challenges for this particular population?

Cotton: It can also be difficult, because they may not want to tell you that or their parents, that they're having this. It's not uncommon where a kid comes in, they have a bad one, and their parents are like ‘This is the first time that's ever happened.’ And the kid says ‘Well, actually, I've been having it for the last year’ and they didn't feel comfortable telling anybody because they were embarrassed, or they thought it wasn't a big deal.

They don't always have, in my experience, that degree of pain that we expect with HS in adults, especially early on. They may still have these lesions that are present, but they aren't necessarily aware of them all of the time because they don't have that same degree of pain until later on in the disease course. And by that point, there could be some significant scarring related to the presence of those lesions, even if they're not aware of it.

HCPLive: Could you explain some of the current therapies or treatment modalities for pediatric HS, as well as any obstacles to research?

Cotton: Treatment in pediatric HS is a little tricky, because we are largely extrapolating from adult studies, and the only FDA-approved therapy at the time of this recording for pediatric HS is adalimumab. And that was never actually studied for HS in pediatric patients. What they did was they sort of extrapolated the adult pioneer studies, and safety data and pharmacokinetic data from other indications that adalimumab has been approved for in pediatric patients, and sort of used that to come to an approval for adalimumab, from ages 12 - 17.

But it's never actually been studied. And the dosing is different, depending on your weight in that age group. We don't really know if that dosing is appropriate or not, so it's an educated guess. But it's still a guess. And it's very difficult to include adolescent patients in clinical trials…There's not really a requirement for companies to think about that until they have completed their phase two trials in adults.

…But in HS, the clinical criteria that we currently use to include patients, a lot of pediatric patients, even with what I would consider to be severe disease don't necessarily have as much scarring as would be necessary to include in one of the clinical trials. So how do we design a trial that still accounts for the severity of disease and gets those patients in without completely excluding them or without changing the patient population so much that it becomes difficult to compare it to other available treatments?

The quotes contained in this interview were edited for clarity.