Derms on Drugs – Episode Summary

Episode Title: What Do Kidney Failure, Short Kids and the Vagus Nerve Have in Common?
Podcast: Derms on Drugs
Hosts: Dr. Matt Zirwas, Dr. Laura Ferris, Dr. Tim Patton
Date: December 19, 2025
Produced By: Scholars in Medicine

Overview

In this "six-pack" episode, Matt, Laura, and Tim deliver a rapid-fire literature review with their signature blend of expertise and wit. They break down recent dermatological research and controversies, exploring unexpected intersections among pediatric growth, kidney risk from beauty products, the vagus nerve’s role in rosacea, and more. The trio dares to ask: what do kidney failure, short kids, and the vagus nerve have in common? Tune in for evidence, debate, practical tips for clinicians, and comedic detours that somehow make dermatology even more enlightening.

Key Discussion Points & Insights

1. Isotretinoin and Height in Kids

Study Discussed: Effect of isotretinoin treatment for acne vulgaris on height in adolescents (Ju et al., JAMA Dermatology)
Key Findings: Isotretinoin may cause a temporary dip in height velocity but does not affect final adult height. The mean difference was 0.67 cm (not statistically significant).
Clinical Relevance: Reassuring data for parents/patients wary of stunted growth from Accutane.
Debate: Matt remains skeptical, noting the non-significant yet consistent trend of slightly shorter stature. Laura counters that temporary slowing is less relevant than final adult height.

B (Laura): “So, you know, in the end, do you care about if your kid's shorter, a little bit shorter for six months versus are you really concerned with their ultimate height, you know, in adulthood? And I would argue it's probably the latter.” (04:03)

A (Matt): “Yeah, it doesn't make people any shorter. We should put everybody on Accutane. That's what I'm… that's my final answer.” (04:44)

2. Atopic Dermatitis, Growth, and Dupilumab

Study Discussed: Decreased risk of reduced linear growth among children with atopic dermatitis receiving dupilumab.
Key Findings:
- Children with atopic dermatitis (AD) showed a higher risk of reduced stature, particularly in boys, older children, and those with chronic steroid use or sleep problems.
- Dupilumab (“Doopy”) cohort: Significantly less likely to remain under-height compared to those on conventional immunosuppressants.
- Mechanism: Chronic inflammation and cytokines (IL-4/IL-13) may suppress growth; dupilumab’s anti-inflammatory action may restore normal growth trajectories.
Notable Moment: Matt notices an oddity in the data—why is <50th percentile in height such a small proportion? Laura figures out that only clinically coded cases counted in the dataset, not all heights measured.

B (Laura): “The sleep disturbance is probably really critical to the height. I remember one time a patient saying: 'Kids grow when they sleep.' And I was like that doesn’t make any sense. And now I actually think it does.” (11:30)

B (Laura): “So most kids don't have any kind of coding, but you are more likely to less likely to have that coded if you are on dupixent.” (30:23)

3. Vagus Nerve Stimulation for Rosacea

Study Discussed: Transcutaneous Auricular Vagus Nerve Stimulation for erythematotelangiectatic rosacea (Lee et al., JAMA Dermatology, Oct 2025)
Key Findings: Small randomized trial; device users had significantly improved rosacea (CEA scale) versus sham. Effects persisted at 15 and 27 weeks. Cost ranges from $278–$600 for devices.
Clinical Relevance: New non-pharmacologic, neuromodulatory option for difficult-to-treat rosacea.
Mechanism: Vagus stimulation modulates the parasympathetic system, possibly addressing neuroinflammation.

C (Tim): “I may kind of mention it to my sort of red fleshy rosacea patients.” (16:12)

A (Matt): “So, as somebody who's interested in anxiety treatment... basically, the idea here is, there's now a general consensus that anxiety disorder is often a parasympathetic/sympathetic imbalance... by stimulating the vagus nerve, you're upregulating people's parasympathetic nervous system…” (16:33)

C (Tim), on home-use device: “I got a hair helmet. Yeah, I wear a hair helmet. My vagus nerve stimulation, I look like Frankenstein when I'm going to bed. It's pretty sweet.” (18:37)

4. N-Acetylcysteine (NAC) as a “Democratized” Dermatology Supplement

Study Discussed: Oral NAC in combination with NB-UVB for vitiligo—pilot study.
Key Findings: NAC may provide a modest improvement when added to phototherapy; Matt notes psychiatric uses (OCD, anxiety) and even personal experience for hangover mitigation.

A (Matt): “I'm always looking for cheap, safe supplements that do stuff... N-acetylcysteine does something.” (20:20)

C (Tim), joking: “And I would bet $1,000 you test this on yourself.” (22:14)

5. Tranexamic Acid—Acne and Melasma, But What About Thrombosis?

Studies Discussed:
- Isotretinoin + Tranexamic Acid for acne: combo group showed bigger, faster improvements.
- Trinetics study on tranexamic acid and thromboembolism risk: flawed methods, but no clear thrombotic signal.
Clinical Relevance: Tranexamic acid could be an effective adjunct in acne and remains “standard of care” for melasma, with negligible thrombosis risk at dermatology doses.

A (Matt): “If this would matter with like a normal full course of isotretinoin, don't know. But like it was a big difference.” (24:44)

A (Matt): “So at that dose, there has been no evidence at all suggesting that it affects how your blood clots. Now, I can't tell you 100% there's definitely not any risk. But the data has been like, we really don't think there's any risk like that. That's my spiel.” (28:33)

6. Topical Ruxolitinib for Hidradenitis Suppurativa (HS)

Study Discussed: Efficacy and safety of ruxolitinib cream in mild to moderate HS.
Key Findings:
- HS patients (Hurley I/II, 3-10 nodules, no tunnels) using ruxolitinib cream had greater AN (abscess/nodule) count reductions than placebo.
- 79% of ruxolitinib users had ≥50% improvement vs. 56% for vehicle; no major safety events or meaningful systemic absorption.

B (Laura): “So kind of cool that we have a topical study... At 16 weeks, the mean AN count dropped by 3.6 in the rux group vs. 2.42 for the vehicle... So they also looked at milestone reductions as secondary endpoints. I think these are kind of more interesting, helpful.” (31:10)

7. Adalimumab Biosimilars in HS—Not All the Same?

Study Discussed: Originator vs. biosimilar adalimumab in HS—retrospective, multi-center.
Key Findings:
- At 52 weeks, originator performed better than biosimilars in maintaining HS response. Loss of response occurred at median 100 weeks (originator) vs. 52 weeks (biosimilar).
- “Switchers” (from originator to biosimilar) also lost response earlier.
- Raises whether real molecular differences exist, not just “nocebo” effect.
Unanswered Questions: Which biosimilars? Are there anti-drug antibodies, lower serum levels, or other mechanistic clues?
Call to Listeners: Matt asks for biosimilar experts to contact the show with insights.

C (Tim): “At week 52, originator was statistically significantly more effective using those three measures... The median time to loss of response was 100 weeks in the originator vs. 52 weeks in the biosimilar group. I mean that's just a big difference.” (39:08)

A (Matt): “I wish I knew of someone in the world who could really talk about... are the biosimilars actually the same?” (40:00)

8. Critical Look at Statistical Models for Drug Study Dropouts

Focus: Matt’s soapbox: Markov chains, multiple imputation, and attrition modeling in long-term trials—are they valid?
Takeaway: Most models cannot account for non-random dropout (which is how real-world studies usually work). Only “as observed” or “non-responder imputation (NRI)” approaches are defensible—everything else is, in Matt's words, “totally meaningless.”

A (Matt): “Completely worthless. Literally all of them, totally worthless. The only way they are ever useful is if people dropped out at random... The real number is somewhere between [as observed and NRI]. Nobody can make up anything more than that.” (47:42)

9. Kidney Damage from Keratin “Smoothing” Treatments

Hot Take: Modern “formaldehyde-free” keratin hair-straightening products contain glyoxylic acid, which can be absorbed through the scalp and transformed into oxalate, causing acute and likely chronic kidney damage, especially in those with scalp conditions.
Clinical Pearls: Counsel patients with any scalp barrier dysfunction (dermatitis, psoriasis) to avoid glyoxylic acid–containing treatments.
Real-World Impact: Acute kidney injury and risk of stones have occurred—even with correct professional use.

A (Matt): “It is possible that everybody who gets one of these keratin treatments to make your hair shinier and smoother is getting mild kidney damage that can be cumulative and is increasing their risk of getting calcium oxalate kidney stones.” (50:46)

Memorable Quotes & Moments

On Personal Experimentation:
- C (Tim): “And I would bet $1,000 you test this [NAC for hangover] on yourself.” (22:14)
- A (Matt): “I have a big bottle of N-acetylcysteine at home. That is correct.” (22:18)
On Vagus Stimulation Devices:
- C (Tim): “I got a hair helmet... My vagus nerve stimulation, I look like Frankenstein when I’m going to bed. It's pretty sweet.” (18:37)
On Stat Models:
- A (Matt): “Statistics, lies, lies, and damn lies. They all just... they’re making it up.” (48:41)
Comic Relief:
- C (Tim): “I've always had silky smooth hair. I'm just blessed. I don't have much of it.” (54:05)

Timestamps for Important Segments

00:52 – Laura on isotretinoin/height in kids
06:45 – Laura: Atopic dermatitis, growth, and dupilumab
13:54 – Tim: Vagus nerve stimulation in rosacea
20:19 – Matt: N-acetylcysteine and vitiligo/psychiatry
23:13 – Matt: Tranexamic acid, acne, and thrombosis risk
29:25 – Laura solves the “height percentile” coding mystery
31:09 – Laura: Ruxolitinib for hidradenitis suppurativa
37:15 – Tim: Adalimumab biosimilars in HS
47:49 – Matt: Attrition bias/statistical model rant
48:41 – Matt: “Statistics, lies, and damn lies” quote
48:49 – Matt: Keratin treatments and kidney risk

Conclusion

This “six-pack” delivers everything the podcast promises: quickfire, practical, and witty breakdowns of dermatology’s hottest questions and controversies. Whether it’s new risks in the hair aisle, advances in HS or rosacea, or tough questions about growth and safety in pediatric derm, the hosts provide essential context and their trademark candor—backed by both the literature and their clinical guts.

For full articles, tables, or further discussion, check out the video component on ScholarsInMedicine.com.

Derms on Drugs – Episode Summary

Overview

Key Discussion Points & Insights

1. Isotretinoin and Height in Kids

Study Discussed: Effect of isotretinoin treatment for acne vulgaris on height in adolescents (Ju et al., JAMA Dermatology)
Key Findings: Isotretinoin may cause a temporary dip in height velocity but does not affect final adult height. The mean difference was 0.67 cm (not statistically significant).
Clinical Relevance: Reassuring data for parents/patients wary of stunted growth from Accutane.
Debate: Matt remains skeptical, noting the non-significant yet consistent trend of slightly shorter stature. Laura counters that temporary slowing is less relevant than final adult height.

B (Laura): “So, you know, in the end, do you care about if your kid's shorter, a little bit shorter for six months versus are you really concerned with their ultimate height, you know, in adulthood? And I would argue it's probably the latter.” (04:03)

A (Matt): “Yeah, it doesn't make people any shorter. We should put everybody on Accutane. That's what I'm… that's my final answer.” (04:44)

2. Atopic Dermatitis, Growth, and Dupilumab

Study Discussed: Decreased risk of reduced linear growth among children with atopic dermatitis receiving dupilumab.
Key Findings:
- Children with atopic dermatitis (AD) showed a higher risk of reduced stature, particularly in boys, older children, and those with chronic steroid use or sleep problems.
- Dupilumab (“Doopy”) cohort: Significantly less likely to remain under-height compared to those on conventional immunosuppressants.
- Mechanism: Chronic inflammation and cytokines (IL-4/IL-13) may suppress growth; dupilumab’s anti-inflammatory action may restore normal growth trajectories.
Notable Moment: Matt notices an oddity in the data—why is <50th percentile in height such a small proportion? Laura figures out that only clinically coded cases counted in the dataset, not all heights measured.

B (Laura): “The sleep disturbance is probably really critical to the height. I remember one time a patient saying: 'Kids grow when they sleep.' And I was like that doesn’t make any sense. And now I actually think it does.” (11:30)

B (Laura): “So most kids don't have any kind of coding, but you are more likely to less likely to have that coded if you are on dupixent.” (30:23)

3. Vagus Nerve Stimulation for Rosacea

Study Discussed: Transcutaneous Auricular Vagus Nerve Stimulation for erythematotelangiectatic rosacea (Lee et al., JAMA Dermatology, Oct 2025)
Key Findings: Small randomized trial; device users had significantly improved rosacea (CEA scale) versus sham. Effects persisted at 15 and 27 weeks. Cost ranges from $278–$600 for devices.
Clinical Relevance: New non-pharmacologic, neuromodulatory option for difficult-to-treat rosacea.
Mechanism: Vagus stimulation modulates the parasympathetic system, possibly addressing neuroinflammation.

C (Tim): “I may kind of mention it to my sort of red fleshy rosacea patients.” (16:12)

A (Matt): “So, as somebody who's interested in anxiety treatment... basically, the idea here is, there's now a general consensus that anxiety disorder is often a parasympathetic/sympathetic imbalance... by stimulating the vagus nerve, you're upregulating people's parasympathetic nervous system…” (16:33)

C (Tim), on home-use device: “I got a hair helmet. Yeah, I wear a hair helmet. My vagus nerve stimulation, I look like Frankenstein when I'm going to bed. It's pretty sweet.” (18:37)

4. N-Acetylcysteine (NAC) as a “Democratized” Dermatology Supplement

Study Discussed: Oral NAC in combination with NB-UVB for vitiligo—pilot study.
Key Findings: NAC may provide a modest improvement when added to phototherapy; Matt notes psychiatric uses (OCD, anxiety) and even personal experience for hangover mitigation.

A (Matt): “I'm always looking for cheap, safe supplements that do stuff... N-acetylcysteine does something.” (20:20)

C (Tim), joking: “And I would bet $1,000 you test this on yourself.” (22:14)

5. Tranexamic Acid—Acne and Melasma, But What About Thrombosis?

Studies Discussed:
- Isotretinoin + Tranexamic Acid for acne: combo group showed bigger, faster improvements.
- Trinetics study on tranexamic acid and thromboembolism risk: flawed methods, but no clear thrombotic signal.
Clinical Relevance: Tranexamic acid could be an effective adjunct in acne and remains “standard of care” for melasma, with negligible thrombosis risk at dermatology doses.

A (Matt): “If this would matter with like a normal full course of isotretinoin, don't know. But like it was a big difference.” (24:44)

A (Matt): “So at that dose, there has been no evidence at all suggesting that it affects how your blood clots. Now, I can't tell you 100% there's definitely not any risk. But the data has been like, we really don't think there's any risk like that. That's my spiel.” (28:33)

6. Topical Ruxolitinib for Hidradenitis Suppurativa (HS)

Study Discussed: Efficacy and safety of ruxolitinib cream in mild to moderate HS.
Key Findings:
- HS patients (Hurley I/II, 3-10 nodules, no tunnels) using ruxolitinib cream had greater AN (abscess/nodule) count reductions than placebo.
- 79% of ruxolitinib users had ≥50% improvement vs. 56% for vehicle; no major safety events or meaningful systemic absorption.

B (Laura): “So kind of cool that we have a topical study... At 16 weeks, the mean AN count dropped by 3.6 in the rux group vs. 2.42 for the vehicle... So they also looked at milestone reductions as secondary endpoints. I think these are kind of more interesting, helpful.” (31:10)

7. Adalimumab Biosimilars in HS—Not All the Same?

Study Discussed: Originator vs. biosimilar adalimumab in HS—retrospective, multi-center.
Key Findings:
- At 52 weeks, originator performed better than biosimilars in maintaining HS response. Loss of response occurred at median 100 weeks (originator) vs. 52 weeks (biosimilar).
- “Switchers” (from originator to biosimilar) also lost response earlier.
- Raises whether real molecular differences exist, not just “nocebo” effect.
Unanswered Questions: Which biosimilars? Are there anti-drug antibodies, lower serum levels, or other mechanistic clues?
Call to Listeners: Matt asks for biosimilar experts to contact the show with insights.

C (Tim): “At week 52, originator was statistically significantly more effective using those three measures... The median time to loss of response was 100 weeks in the originator vs. 52 weeks in the biosimilar group. I mean that's just a big difference.” (39:08)

A (Matt): “I wish I knew of someone in the world who could really talk about... are the biosimilars actually the same?” (40:00)

8. Critical Look at Statistical Models for Drug Study Dropouts

Focus: Matt’s soapbox: Markov chains, multiple imputation, and attrition modeling in long-term trials—are they valid?
Takeaway: Most models cannot account for non-random dropout (which is how real-world studies usually work). Only “as observed” or “non-responder imputation (NRI)” approaches are defensible—everything else is, in Matt's words, “totally meaningless.”

A (Matt): “Completely worthless. Literally all of them, totally worthless. The only way they are ever useful is if people dropped out at random... The real number is somewhere between [as observed and NRI]. Nobody can make up anything more than that.” (47:42)

9. Kidney Damage from Keratin “Smoothing” Treatments

Hot Take: Modern “formaldehyde-free” keratin hair-straightening products contain glyoxylic acid, which can be absorbed through the scalp and transformed into oxalate, causing acute and likely chronic kidney damage, especially in those with scalp conditions.
Clinical Pearls: Counsel patients with any scalp barrier dysfunction (dermatitis, psoriasis) to avoid glyoxylic acid–containing treatments.
Real-World Impact: Acute kidney injury and risk of stones have occurred—even with correct professional use.

A (Matt): “It is possible that everybody who gets one of these keratin treatments to make your hair shinier and smoother is getting mild kidney damage that can be cumulative and is increasing their risk of getting calcium oxalate kidney stones.” (50:46)

Memorable Quotes & Moments

On Personal Experimentation:
- C (Tim): “And I would bet $1,000 you test this [NAC for hangover] on yourself.” (22:14)
- A (Matt): “I have a big bottle of N-acetylcysteine at home. That is correct.” (22:18)
On Vagus Stimulation Devices:
- C (Tim): “I got a hair helmet... My vagus nerve stimulation, I look like Frankenstein when I’m going to bed. It's pretty sweet.” (18:37)
On Stat Models:
- A (Matt): “Statistics, lies, lies, and damn lies. They all just... they’re making it up.” (48:41)
Comic Relief:
- C (Tim): “I've always had silky smooth hair. I'm just blessed. I don't have much of it.” (54:05)

Timestamps for Important Segments

00:52 – Laura on isotretinoin/height in kids
06:45 – Laura: Atopic dermatitis, growth, and dupilumab
13:54 – Tim: Vagus nerve stimulation in rosacea
20:19 – Matt: N-acetylcysteine and vitiligo/psychiatry
23:13 – Matt: Tranexamic acid, acne, and thrombosis risk
29:25 – Laura solves the “height percentile” coding mystery
31:09 – Laura: Ruxolitinib for hidradenitis suppurativa
37:15 – Tim: Adalimumab biosimilars in HS
47:49 – Matt: Attrition bias/statistical model rant
48:41 – Matt: “Statistics, lies, and damn lies” quote
48:49 – Matt: Keratin treatments and kidney risk

Conclusion

For full articles, tables, or further discussion, check out the video component on ScholarsInMedicine.com.

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What Do Kidney Failure, Short Kids and the Vagus Nerve Have in Common?

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Summary

Derms on Drugs – Episode Summary

Overview

Key Discussion Points & Insights

1. Isotretinoin and Height in Kids

2. Atopic Dermatitis, Growth, and Dupilumab

3. Vagus Nerve Stimulation for Rosacea

4. N-Acetylcysteine (NAC) as a “Democratized” Dermatology Supplement

5. Tranexamic Acid—Acne and Melasma, But What About Thrombosis?

6. Topical Ruxolitinib for Hidradenitis Suppurativa (HS)

7. Adalimumab Biosimilars in HS—Not All the Same?

8. Critical Look at Statistical Models for Drug Study Dropouts

9. Kidney Damage from Keratin “Smoothing” Treatments

Memorable Quotes & Moments

Timestamps for Important Segments

Conclusion

Summary

Derms on Drugs – Episode Summary

Overview

Key Discussion Points & Insights

1. Isotretinoin and Height in Kids

2. Atopic Dermatitis, Growth, and Dupilumab

3. Vagus Nerve Stimulation for Rosacea

4. N-Acetylcysteine (NAC) as a “Democratized” Dermatology Supplement

5. Tranexamic Acid—Acne and Melasma, But What About Thrombosis?

6. Topical Ruxolitinib for Hidradenitis Suppurativa (HS)

7. Adalimumab Biosimilars in HS—Not All the Same?

8. Critical Look at Statistical Models for Drug Study Dropouts

9. Kidney Damage from Keratin “Smoothing” Treatments

Memorable Quotes & Moments

Timestamps for Important Segments

Conclusion