Welcome to this December twenty twenty-five review of Dermatologic Surgery. We've got four main articles to walk through this month — a basic-science mechanism study on laser-assisted scar improvement, a cross-sectional look at Mohs content on TikTok, a retrospective analysis tracking the progression from simple abscess to hidradenitis suppurativa, and a technique piece describing a new buried suture variant. I'll also fold in two shorter communications that ran alongside two of these pieces, since they're quick and worth knowing about. Let's get into it.

First up is a mechanism-exploration study out of Guangdong, looking at early intervention with carbon dioxide ablative fractional laser — CO2 AFL — on surgical scars, and specifically asking what's actually happening at the cellular level when we do this. You've probably already seen the clinical phenomenon yourself or heard of it: treating a fresh incision with a fractional CO2 laser in the early postoperative period seems to soften or even erase the eventual scar line. The clinical effect has been reported by multiple groups, but the actual mechanism has stayed murky. This group set out to nail down the biology, with a specific hypothesis going in — that CO2 AFL activates a gene called Trps1, which then kicks off Wnt/beta-catenin signaling, which in turn recruits hair follicle stem cells into the wound-healing process.

This is a basic-science, animal-model study, not a clinical trial, so the methods look very different from what you'd see in a human cohort paper. They used several strains of transgenic mice — including Lgr5 and Krt14 fluorescent reporter lines — specifically so they could literally watch, under fluorescence, where hair follicle stem cells and epidermal stem cells were migrating to during wound healing. That's the methodological logic worth flagging: you can't track stem cell lineage and fate in human tissue this way, so a genetically engineered mouse model is really the only tool that lets you visually confirm "this specific stem cell population moved into the wound and proliferated." They made full-thickness dorsal incisions, closed them, then treated one side with CO2 AFL on day two post-wounding at varying energy settings, leaving the other side untreated as an internal control — a nice paired design that controls for animal-to-animal variability. They first ran a dose-finding exercise across three energy settings and landed on a setting of ten percent density, twenty millijoules, and three hundred hertz as producing the least visible incision line — that's their optimal parameter, and it's the one used for all subsequent experiments. From there they layered on histology, transcriptome sequencing, quantitative PCR, and western blotting to build a mechanistic case, rather than relying on any single readout.

On results: histologically, the treated incisions had thinner, less prominent scar lines, and this showed up as early as day three to seven, with the epidermis actually thickening transiently and hair follicles and sebaceous glands starting to repopulate near the incision — something essentially absent on the untreated side. Collagen typing shifted favorably too, with more type one collagen early and more type three collagen and a more organized, skin-like collagen architecture by two weeks, versus the more disorganized pattern you'd expect in ordinary scar. On the transcriptomic side, the treated tissue showed enrichment in Wnt signaling pathway genes, extracellular matrix interaction genes, and DNA replication genes — and specifically, Lgr6, Wnt5a, and Trps1 were all significantly upregulated in the treated group by day seven. That was mirrored at the protein level, where Wnt5a and beta-catenin were elevated in treated tissue at both early and late time points. And using the fluorescent reporter mice, they could actually see it directly — Lgr5-positive and Lgr6-positive hair follicle stem cells, along with K14-positive epidermal stem cells, appearing in the center of the incision in the treated group by day seven, cells that simply were not present in that location in the untreated control.

Putting it together, the authors conclude that early CO2 AFL intervention seems to work by activating Trps1, which drives Wnt/beta-catenin signaling, which recruits hair follicle stem cells into the healing incision — essentially recruiting an adnexal regenerative program rather than a purely fibrotic one. The obvious limitation here is one you'd expect from any translational basic-science paper — this is entirely a mouse model, using engineered reporter strains and a straight surgical incision, which is a much cleaner and more homogeneous wound than what we create clinically after excisions of variable size, tension, and anatomic location. There's no long-term scar outcome scoring beyond day twenty-eight, and no human validation at all in this paper. So take the mechanistic story as hypothesis-generating and biologically plausible, not as proof that this pathway is the operative one in human patients.

Practically, this isn't practice-changing on its own — you're very likely already doing early post-op fractional CO2 laser touch-ups on high-risk scars, and this paper doesn't give you a new protocol or a new energy setting to adopt clinically, since their optimal parameter was derived and validated only in mouse skin. What it does give you is a satisfying, evidence-backed answer to the "why does this work" question you may get from curious patients or trainees — the working model now being that fractional ablation isn't just mechanically disrupting scar tissue, it's biologically waking up follicular stem cell niches and channeling healing toward a more regenerative, hair-bearing, adnexa-preserving phenotype rather than pure fibrosis. Interesting and mechanistically satisfying, but not yet something that should change your energy settings or timing in clinic.

Next, a cross-sectional analysis looking at the quality of Mohs-related content on TikTok — this falls into the "state of digital health information" genre rather than a therapeutic study, but it's directly relevant to what your patients are seeing before they ever sit in your chair. The premise is straightforward: TikTok has become a major vector for health information, good and bad, and the authors wanted to formally grade what's actually circulating about Mohs micrographic surgery under the hashtag "Mohs."

Methodologically, they pulled the top one hundred hashtagged videos over a five-day window in December twenty twenty-three, applied inclusion and exclusion criteria to end up with seventy relevant videos, and then had two independent reviewers score each one using three validated instruments — the DISCERN instrument, the JAMA benchmark criteria, and the Global Quality Scale. Using three different validated tools rather than just one is a sensible design choice here, since each instrument captures something slightly different — DISCERN is oriented toward treatment-decision quality, JAMA toward source credibility and transparency, and the Global Quality Scale toward general usefulness to a patient — and triangulating across all three makes the "low quality" conclusion much more robust than any single score would.

The results were fairly stark. Of the seventy included videos, roughly seven in ten were created by patients themselves, and only about one in seven were made by physicians, with the remainder from nurses or Mohs technicians. Across all videos, the average DISCERN score was low — about one point six on whatever scale the tool uses, which the authors characterize plainly as poor quality — and physician-created videos scored significantly better, roughly two point four, a real and statistically significant gap. But even that physician-made average still sits well below what you'd call a high-quality benchmark, so this is a case of statistically significant but only partially reassuring — physicians do better, but "better than poor" is still not "good." The JAMA and Global Quality Scale scores told the same story, averaging around one point four and one point eight respectively, both toward the low end of quality. Meanwhile, these seventy videos averaged roughly four hundred fifty thousand views apiece, with some individual videos reaching into the millions — so the reach of this low-quality content is genuinely enormous, dwarfing anything most of us could produce as individual clinicians.

The authors' discussion is appropriately restrained — they acknowledge that DISCERN, JAMA, and the Global Quality Scale were all originally built for written material, not short-form video, and that no validated scoring system yet exists specifically for social media video content, so these results should be read as directionally informative rather than as a precise psychometric verdict. They also note this pattern mirrors what's been found in other dermatologic TikTok content, like acne videos, so this isn't a Mohs-specific problem, it's a broader pattern in dermatology-adjacent social media.

The practical takeaway here isn't a change to your surgical practice, but it is a call to action worth taking seriously for your patient-facing presence: patients are getting most of their pre-visit Mohs information from other patients on TikTok, not from clinicians, and that content is measurably low quality despite massive reach. Physician-created content, while still imperfect, is significantly better — which is really the actionable point. If you or your practice have any interest in patient education content, this paper is a reasonably strong evidence-based nudge to get physician voices into that space, since right now the vacuum is being filled by anecdote.

Alongside that piece, this issue also carried a short communication describing a homemade smoke evacuation device — essentially a flexible, extendable exhaust tube connected to an external fan, nicknamed by the authors as a "Korean barbecue-style" ventilator, designed to sit near the electrocautery or laser tip during wart treatments and adapt to different patient positions without needing to be repositioned constantly. It's a letter, not a study, so there's no outcomes data — just a practical build description. The headline number worth remembering is cost: the authors report the entire system, fan and tubing included, runs about one hundred thirty-six dollars, positioned as a cheap, accessible alternative for practices without a built-in smoke evacuation system. Worth knowing about if smoke evacuation infrastructure has been a budget sticking point in your own space, though obviously this hasn't gone through any formal safety or efficacy testing against commercial units.

Third, a retrospective analysis from Atrium Health Wake Forest Baptist tracking how often patients who first present with a plain cutaneous abscess go on to be diagnosed with hidradenitis suppurativa, and how long that transition takes. The clinical problem is one we all know — HS is frequently diagnosed late, often after irreversible scarring and tunneling have already set in, and the authors wanted to know whether the anatomic pattern of an initial "simple" abscess could serve as an early warning sign, essentially asking whether we're missing a diagnostic window when these patients first show up.

This is a retrospective chart review spanning 2012 to 2023, built around patients who initially presented with a coded cutaneous abscess and had at least ten years of follow-up available, specifically excluding anyone who already carried an HS diagnosis at that first visit. That long follow-up requirement is the key methodological choice here — the authors don't spell out their reasoning explicitly, but a ten-year window makes sense if you're trying to capture a diagnosis that might not emerge for years after the index abscess, which is exactly what they found. They then compared anatomic location of the abscess, demographics, and comorbidities between those who eventually got an HS diagnosis and those who never did, using standard chi-squared and t-test comparisons.

Out of four hundred seventy-one patients meeting inclusion criteria, seventy-one — about one in seven — were eventually diagnosed with HS, and that HS group skewed heavily female, at about eighty percent. Patients who went on to develop HS presented with their first abscess significantly younger, on average around age twenty, compared to age twenty-five in those who never developed HS — a five-year gap that's both statistically significant and clinically meaningful, since it suggests earlier abscess onset itself is a soft warning sign. The average time from that first abscess to an eventual formal HS diagnosis was about two and a half years, though the range was wide — anywhere from the same month to as long as roughly twelve years, underscoring just how variable the diagnostic delay can be.

The anatomic clustering finding is really the headline result. Abscesses in the axilla, the inframammary fold, and the inguinal folds were all significantly more common in the group that eventually got diagnosed with HS — for example, axillary involvement showed up in roughly one in three of the eventual HS patients versus only about one in seven of those who never developed HS, and that gap was statistically robust. Inframammary involvement showed a similar pattern, and inguinal fold involvement as well. By contrast, anogenital and back locations did not differ significantly between groups, meaning those sites are far less specific for predicting a future HS diagnosis. When the authors grouped all the "typical" HS-distribution sites together, patients presenting with an abscess in one of those typical locations were roughly seven times more likely to eventually be diagnosed with HS than patients whose abscess was somewhere atypical — a striking and clinically intuitive signal. On comorbidities, diabetes, obesity, hyperlipidemia, and other dermatologic conditions were all statistically more common in the eventual-HS group, though the absolute differences were fairly small in several cases — obesity, for instance, at about twenty-one percent versus twenty percent — so those associations are statistically real but not something you'd necessarily use alone to flag a patient.

The authors are appropriately honest about the limitations: this is a single-center retrospective study, it doesn't capture abscess patients managed through primary care or the emergency department who never made it into dermatology's charts, it relies on ICD-10 coding accuracy for both the abscess and the eventual HS diagnosis, and patients captured toward the tail end of the study window may simply not have had enough follow-up time yet to manifest HS. They also note their own diagnostic delay figure of roughly two and a half years is actually shorter than delays reported in other cohorts using patient-reported symptom-to-diagnosis timelines, which have run as long as seven to ten years — so methodology and data source clearly affect how "delayed" this looks.

For practical purposes, this is a genuinely useful pattern-recognition tool rather than a definitive diagnostic algorithm. If you're the one lancing or excising an abscess in the axilla, inframammary fold, or groin — especially in a younger woman — this data supports a low threshold for asking about recurrence, family history, and other stigmata of HS at that very first encounter, rather than waiting for a second or third recurrence to raise the question. It won't change your surgical management of an acute abscess, but it's a reasonable nudge toward earlier counseling and referral in the right anatomic context.

Last, a technique piece describing the buried "clothesline" suture, presented as a variation on Yag-Howard's zipper stitch. As a communication rather than a study, there's no results or limitations section to walk through — this is purely a description of technique and the authors' rationale, so let's go through the mechanics.

The original zipper stitch is a running buried vertical mattress closure with two tie points, one at each end of the incision, using a loop between the last two throws to bury the knot. The modification here collapses that down to a single tie point at the distal end only. The key maneuver is what they call the "clothesline" — at the proximal end, a buried vertical mattress suture is placed, and rather than tying off immediately, the free end is stretched by a hemostat or assistant along the length of the wound bed, running along one side of the excisional edge. Subsequent running buried vertical mattress sutures, placed every three to four millimeters, are then thrown so that they incorporate this clothesline strand as they cross from one side of the wound to the other, essentially lashing the whole running closure to that single long strand before the final knot is tied and buried a few millimeters below the epidermal surface. If a subcutaneous inverted cross-mattress stitch is also being used, the clothesline is simply passed beneath it. Poliglecaprone is their suture of choice, favored for tensile strength, low friction, and easy handling, and epidermal edges can be reinforced afterward with cyanoacrylate glue or Steri-Strips if desired.

The stated rationale, straight from the authors, is that this design needs only one surgical tie point instead of two, doesn't require a separate epidermal suture, and — because the clothesline strand can be tensioned progressively like a purse-string as the closure proceeds — gives you adjustable control over both hemostasis and final incisional length depending on how much tension you dial in before the final knot. They're upfront about the trade-offs too: it uses more overall suture material, though they don't think that meaningfully affects cost, and there's some added chair time spent managing the loose clothesline end until the desired tension is achieved.

As a practical takeaway, this sits squarely in the "useful technique refinement" category rather than practice-changing territory — it's a reasonable option to have in your toolkit for closures where you want adjustable, purse-string-like tension control and eversion with a single buried knot, particularly on longer or higher-tension excisions, but there's no comparative data here on cosmetic outcome, closure time, or complication rate versus the standard zipper stitch or a conventional running buried vertical mattress. Try it if the concept appeals to you, but don't expect published outcome superiority to back it up yet.

Riding along with that piece was a short "how we do it" on button osteoma excision — a straightforward technical walkthrough rather than a study. The steps are simple: mark the incision along relaxed skin tension lines, infiltrate with lidocaine and epinephrine into both skin and the subgaleal space, incise down to subcutaneous fat and then redirect along the frontalis fibers to the periosteum, incise the periosteum at the base of the osteoma and elevate it to expose the lesion clearly, then place a one-centimeter straight osteotome tangentially at the osteoma's base and use short mallet strikes to separate it from the calvarium, smoothing the bony surface afterward if needed, and closing in layers with absorbable suture under a pressure dressing. No outcomes data is presented — it's purely a procedural pearl for a lesion most of us encounter only occasionally, so it's worth bookmarking for the next time one crosses your schedule rather than something requiring any change to how you already think about these lesions.

That wraps our four main articles and their companion pieces for this December issue. The throughline this month is really about early recognition and mechanism — recognizing HS earlier from abscess location, understanding mechanistically why early laser intervention might improve scars, and being honest about where our patients are actually getting their information versus where we'd like them to get it. Thanks for listening, and I'll see you next issue.