Welcome back to the journal review. This month we're working through the August 2026 issue of Dermatologic Surgery, and we've got four pieces on the docket — a commentary on anogenital anatomy, an original randomized trial comparing two laser-assisted topical therapies in vitiligo, a reconstructive conundrum on a large lower lip defect, and an original experimental study testing how well skin shields actually protect against different laser wavelengths. Let's get into it.

First up is a commentary — so no methods, no results, this is opinion and synthesis — written by Nahid Vidal at Mayo Clinic in response to a review article by Jeha and colleagues on surgical anatomy of the genital and inguinal region for the dermatologic surgeon. The commentary's central argument is that anogenital anatomy deserves the same rigor we give head and neck anatomy, and right now it doesn't get it. Formal training in this area is thin, yet the stakes are enormous — continence, sexual function, body image. A technical misstep here isn't just a suboptimal scar, it's potential dyspareunia, erectile dysfunction, sphincter dysfunction, or anal stenosis. The commentary pulls out a few very practical technical pearls from the parent review worth flagging for your own practice: anogenital surgery under local anesthesia is genuinely difficult to execute comfortably, because achieving adequate retraction while keeping the patient comfortable is a real tension — bilateral retraction alone can generate stretch pain, for instance around the clitoris. And because local anesthesia distorts this tissue so much more than it distorts, say, facial skin, the commentary recommends marking your orientation with suture — Ethibond or nylon — rather than ink or hash marks, since ink just doesn't survive the tissue shift.

The piece also spends real time on the sex-based gap in anatomic education. Female anogenital anatomy has historically been taught and studied less rigorously than male anatomy, often using male anatomy as the implicit reference standard, and the commentary suggests this isn't just an academic curiosity — it may be contributing to outcome disparities. It cites a meta-analysis finding that vulvar extramammary Paget disease is more likely to be treated with radical surgery than the penoscrotal counterpart, which is a striking data point suggesting our comfort and anatomic fluency may be shaping treatment aggressiveness. There's also a good clinical reminder that anatomy here isn't static — vulvovaginal atrophy and labial resorption with estrogen loss, pelvic organ prolapse shifting the spatial relationships of urethra, vagina, and anus, and analogous age- and comorbidity-driven changes on the male side with vascular disease, diabetes, and prior surgery. A single anatomic mental model for "the anogenital region" across a patient's lifespan will fail you.

The commentary closes with two points worth carrying into your own practice. One is a genuine plug for knowing your limits — recognizing when a case needs multidisciplinary input from urology, colorectal, gynecology, or plastic surgery colleagues, particularly when tumors approach the urethra, vagina, rectum, or deeper erectile or sphincteric structures. The other is more of an advocacy point: current reimbursement for anogenital work, including Mohs micrographic surgery in this region, doesn't reflect its complexity — the example given is that a vulvar biopsy reimburses less than other special sites like lip or nail, and substantially less than a penile biopsy. Nothing here is practice-changing in a technical sense, but it's a worthwhile recalibration of how seriously we should be treating anatomic preparation before we ever pick up a blade in this region.

Next, an original randomized clinical trial out of Assiut University in Egypt, looking at fractional carbon dioxide laser-assisted delivery of topical methotrexate versus topical 5-fluorouracil in stable, nonsegmental vitiligo, with a secondary interest in interleukin-23, or IL-23, as a biomarker.

The background here is straightforward: vitiligo treatment remains unsatisfying across the board, and there's growing interest in using ablative fractional lasers to punch physical channels through the stratum corneum so that topical drugs — which otherwise can't penetrate intact skin — get where they need to go. Topical 5-fluorouracil with laser assistance already has some track record in vitiligo. Topical methotrexate is the newer entrant, attractive because, unlike the oral route, it's believed to avoid the hepatotoxicity and hematologic risk of systemic methotrexate. The specific gap the authors identify is that nobody had directly compared laser-assisted topical methotrexate against laser-assisted topical 5-fluorouracil, and nobody had looked at lesional — as opposed to just serum — interleukin-23 in vitiligo at all.

Methodologically, this was a randomized trial with an intra-patient split design — each patient contributed two comparable, symmetric vitiligo patches, one treated with the laser at a lower energy and one at a higher energy, within their assigned drug arm, methotrexate for one group of twenty-one patients, 5-fluorouracil for another twenty-one, three monthly sessions each. Using each patient as their own control for the energy comparison is a sensible design choice you'll see often in dermatology device trials, since it controls for interpatient variability in things like skin type, disease duration, and baseline severity that would otherwise muddy an energy-dose comparison. It's worth noting the trial was open-label — investigators knew group assignments — which the authors don't dwell on, but which matters for interpreting the photographic grading and satisfaction outcomes, even though the photo evaluators themselves were blinded.

On the statistics side, this paper leans heavily on repeated-measures ANOVA, or analysis of variance, to handle the primary outcome — the modified Vitiligo Area Scoring Index, or VASI, measured at baseline, one month, and three months. It's worth pausing on why that's the right tool here rather than just running a series of separate t-tests at each timepoint. Repeated-measures ANOVA is built for exactly this scenario: the same lesion measured repeatedly over time, which means the data points within a patient are correlated with each other rather than independent. If you ran naive pairwise t-tests instead, you'd inflate your false-positive rate every time you added another comparison, and you'd also be ignoring the fact that a given patient's own baseline severity is a good predictor of their own follow-up values. Repeated-measures ANOVA instead partitions the variability into what's attributable to time, what's attributable to treatment group, and what's just individual patient variation, letting the model ask whether change over time differs meaningfully between groups while accounting for that within-patient correlation. The authors then applied Tukey correction for the pairwise follow-up comparisons, which is a standard guard against false positives when you're making multiple comparisons off the same overall model.

So what did they find. Both treatments worked, and importantly, they worked about equally well. At three-month follow-up, percent reduction in VASI was around 28 percent in both the high-energy laser plus methotrexate group and the high-energy laser plus 5-fluorouracil group — essentially identical — while the lower-energy groups showed somewhat less improvement, roughly 24 percent with methotrexate and 18 percent with 5-fluorouracil, though the paper reports no statistically significant difference between drugs overall. Interestingly, improvement kept building between the one-month and three-month mark specifically in the methotrexate groups, while the 5-fluorouracil groups had already peaked earlier — so if you're counseling a patient on methotrexate, the message is that patience through the third month matters. Photographic grading told a similar story: at one month, the high-energy 5-fluorouracil arm actually showed more "excellent" repigmentation, a statistically significant edge, but by three months that gap had closed and was no longer significant. Patient satisfaction was reasonably good and statistically similar across arms, running roughly in the range of half to two-thirds of patients rating themselves satisfied or very satisfied. Safety was reassuring for both drugs — no significant differences in erythema, pain, or hyperpigmentation between methotrexate and 5-fluorouracil, though a small handful of patients on each drug had transient, self-resolving lab abnormalities, mild liver enzyme elevation in a few methotrexate and 5-fluorouracil patients, and a slight hemoglobin dip in two 5-fluorouracil patients — nothing that changed management, but a reminder that even topical, laser-assisted delivery of these agents warrants baseline and interval labs, which the investigators appropriately built into the protocol.

On the biomarker side, both serum and lesional IL-23 dropped significantly after treatment in both groups. The serum drop was significantly greater with methotrexate than with 5-fluorouracil, while the lesional tissue drop was significantly greater with the higher laser energy regardless of which drug was used. The authors frame IL-23 as a promising treatment-response biomarker, though I'd flag that this is hypothesis-generating rather than something with any current clinical application — you're not ordering serum IL-23 levels on your vitiligo patients tomorroow.

For limitations, the sample size is modest — forty-two patients, ninety-four patches — and the trial was open-label, both of which the authors don't extensively dwell on but which you should factor into how much weight you give the finer-grained differences, like the early photographic edge for 5-fluorouracil. There's also inherent selection bias in only including patients with stable, refractory vitiligo who'd already failed conventional therapy, which limits generalizability to earlier-line patients.

Practically: this isn't practice-changing in the sense of altering your current disease management, since most Mohs surgeons and dermatologic oncologists aren't managing vitiligo. But if you do collaborate with medical dermatology colleagues on combination physical-topical vitiligo approaches, the actionable takeaway is that laser-assisted topical methotrexate appears to be a legitimate, comparably effective, similarly safe alternative to laser-assisted 5-fluorouracil, with the added appeal of a theoretically more favorable systemic safety profile — worth knowing about as an option, though the IL-23 biomarker angle remains research-stage.

Third, a reconstructive conundrum — so this is a case-based technique piece, format is presentation, question, then solution and discussion, no formal results or limitations section in the traditional sense.

A 77-year-old man had a 3-centimeter squamous cell carcinoma of the mid lower lip excised, leaving a full-thickness, 5-centimeter defect — about half the length of the lip — spanning mucosa, vermillion, skin, and part of the orbicularis oris muscle. The question posed to the reader is how you'd reconstruct a defect that large in the mid lower lip without resorting to a staged flap.

Their solution was a bilateral mucosal V-Y advancement island flap. Two triangular island flaps were raised on either side of the defect, incorporating mucosa, vermillion, skin, and underlying muscle, dissected down to the orbicularis oris to allow medial advancement, then sutured to each other in the midline. Inferiorly, they used a W-plasty rather than a single standing cone excision specifically to avoid crossing the mental crease — a deliberate aesthetic choice to keep the resulting scar out of a visually conspicuous landmark. At one-year follow-up, the patient had complete healing and an excellent cosmetic result, no significant microstomia, and only a transient issue with oral incontinence for liquids, which the authors attribute to temporary neuromuscular dyscoordination of the reconstructed orbicularis oris and altered proprioception — this fully resolved after ten sessions of targeted orofacial physical therapy focused on lip seal strength and coordination.

The discussion walks through why they didn't reach for the more familiar options. A wedge excision, even with W-plasty, wasn't feasible given the defect size, due to microstomia risk and wound tension. The Abbe flap, a cross-lip flap based on the labial artery, is a reasonable option for defects this size but requires a two-stage procedure with a real risk of flap damage from mouth opening between stages. The Karapandzic flap handles large lower lip defects well but comes with predictable microstomia as a trade-off. Bilateral lip advancement or a stair-step design were also considered but come with either wide chin incisions or a geometrically obvious scar that doesn't blend into the mental crease. The bilateral mucosal V-Y advancement flap threaded the needle: single-stage, technically simpler than cross-lip or circumoral options, low microstomia risk, and a cosmetically acceptable trade-off of slight vermillion shortening.

The authors are appropriately specific about patient selection here, which is really the main teaching point. This flap is best suited to centrally located defects — off-center placement risks an asymmetric vermillion — and requires adequate laxity and volume in the adjacent labial mucosa for tension-free advancement. It's a poor choice when there's scarring from prior surgery limiting mucosal laxity, when the defect involves very extensive muscle loss beyond what two advancement flaps can reasonably reconstitute, or when the defect extends significantly onto the chin, where something with more structural bulk, like a Karapandzic flap, would serve better. For your own practice, this is a genuinely useful single-stage tool to have available for that specific niche — the large, but not too large, centrally located full-thickness lower lip defect — and worth remembering as an alternative to defaulting to Karapandzic or Abbe reconstruction in appropriately selected patients.

Last, an original study, though I'd characterize it more as a bench safety experiment than a clinical trial — there's no patient population, no inferential statistics, just direct physical measurement, so we'll walk through it as reported rather than teaching a statistical test.

The clinical problem: as laser and intense pulsed light, or IPL, procedures are increasingly performed over larger body surface areas, there's growing risk of inadvertently hitting nontarget pigmented structures — melanocytic nevi, tattoos — with treatment energy, and there have been isolated case reports of concerning changes, including pseudomelanoma, in nevi exposed to laser energy. The European Society for Laser Dermatology recommends covering benign nevi with white tape, but the evidence base for what actually blocks energy transmission adequately is thin. This study set out to directly measure, with a laser power and energy meter, how much energy actually gets through several commonly used protective materials — commercial adhesive skin shields, laser treatment patches, silk tape, one and two layers of paper tape, and laser versus IPL eye shields — when exposed to five different energy sources: a 532-nanometer KTP laser, an 810-nanometer diode laser, a 1,064-nanometer neodymium-doped yttrium aluminum garnet, or Nd:YAG, laser, a 2,940-nanometer erbium-doped yttrium aluminum garnet, or Er:YAG, laser, and IPL with three different filters.

The method itself is simple and appropriate to the question: fire the device at a bare sensor to get a baseline energy reading, then repeat with each material interposed, and calculate percent transmission. No blinding or randomization is needed here because there's no subjective outcome and no human variability to control for — this is a straightforward physics measurement, which is exactly the right level of methodological complexity for this question.

The headline result is that the purpose-built adhesive skin shields performed impressively well across almost every device tested. Transmission was around 4 percent with the KTP laser, about 7 percent with the diode laser, roughly 1 percent with the Er:YAG laser, and under 2 percent across all three IPL filters — meaning the skin shields blocked the vast majority of energy in each of those scenarios. The one major exception, and this is the clinically important finding, was the 1,064-nanometer Nd:YAG laser. Even though the skin shield's measured transmission with the Nd:YAG was only around 11 percent, which sounds protective on paper, the shield itself, along with both types of eye shields tested, actually caught fire and began vaporizing during testing. In other words, the material failed catastrophically rather than safely absorbing the energy — a transmission percentage alone doesn't capture that risk. By contrast, silk and paper tape provided much more modest protection across the board, generally blocking only somewhere between a quarter and two-thirds of the energy depending on wavelength, and the specialized laser treatment patches, designed for plume reduction rather than shielding, transmitted the most energy of all the products tested, in some cases over 90 percent — so those clearly aren't fit for this repurposed use.

The discussion is appropriately narrow here — this is a materials-testing study, not a clinical trial, so the authors aren't claiming clinical efficacy, just physical blocking capacity, and they're honest that no prior study has established a definitive best practice or even conclusively linked incidental nevus exposure to malignant transformation; the case reports remain isolated. The obvious limitation, which the authors don't need to belabor because it's inherent to the design, is that this is bench data on a sensor plate, not skin — there's no accounting for how actual tissue optical properties, curvature, or patient movement might change real-world protection, and there's no clinical outcomes data attached.

The practical takeaway here is genuinely actionable for anyone doing laser or IPL work over larger fields where nevi or tattoos might be in the treatment path: these commercial skin shields are a reasonable, effective option for the KTP, diode, Er:YAG lasers, and IPL across all three filters tested, and they clearly outperform tape. But — and this is the one you should actually change practice on — do not rely on these skin shields, or the eye shields, for protection against a 1,064-nanometer Nd:YAG laser. The fire and vaporization finding is a real safety hazard, not just a suboptimal transmission number, and it means an alternate protective strategy is needed whenever Nd:YAG energy might reach a shielded nontarget area.

That wraps our four articles from the August issue. A commentary reminding us that anogenital anatomic mastery is a discipline unto itself, a well-designed trial showing topical methotrexate holds its own against 5-fluorouracil for laser-assisted vitiligo therapy, an elegant single-stage flap solution for large central lower lip defects, and a bench study with one very concrete safety warning about Nd:YAG lasers and skin shields. Thanks for listening, and we'll see you next month.