This month’s news from across the specialty

January 1, 2023

In this monthly column, members of the DermWorld Editorial Advisory Workgroup identify exciting news from across the specialty.  

In October’s Dialogues in Dermatology, Dr. Scott Elman, double board-certified internist and dermatologist, discusses important “new medications used in primary care and their dermatologic side effects.” A focus of the talk is diabetes drugs, given that treatment of diabetes has exploded over the past 10-15 years.

The DPP4-inhibitors (i.e., sitagliptin) have become very popular, and two important studies have shown an increased risk of bullous pemphigoid (BP) in these patients. Dr. Elman believes that the DPP4-inhibitors are the most likely of the diabetes drugs to cause BP.

SGLT-2 inhibitors, also known as the “flozins” (i.e., empaglaflozin), increase urinary excretion of glucose and are used in both diabetes and heart failure. However, because of increased urination of glucose, these medications carry an increased risk of yeast infections. Dr. Elman also notes that these medications carry an increased risk of Fournier’s gangrene, and patients may present with a new rash in the genital area.

GLP-1 receptor agonists (i.e., semaglutide) are now used in patients as a treatment for obesity. They tend to be very well tolerated by patients without the side effect of hypoglycemia. Due to the number of skin manifestations secondary to obesity that we see, there could potentially be a role for these medications to treat dermatologic diseases such as acanthosis nigricans, hidradenitis, and more.

Although unrelated to diabetes, proton pump inhibitors are a newly recognized medication that can cause SCLE. Think about this with your newly diagnosed SCLE patient who just recently started omeprazole.

In the past few years, artificial intelligence has been a hot topic in medicine, especially in dermatology and dermatopathology. In a recent study, Snyder and colleagues reported their experience on using a deep learning model for screening melanocytic lesions (Am J Dermatopathology. 2022. 44:9, 650-7). The diagnosis of difficult melanocytic lesions such as Spitz nevus, melanoma, and severely atypical nevus is a challenge even for expert pathologists. In this paper, the authors utilized whole-slide imaging (a scanned image of the entire microscopic glass slide) and a deep network learning model. Twenty-seven cases of malignant melanoma, Spitz nevi, and benign nevi were utilized as a training set. They subsequently used 34 additional cases for independent evaluation. The final model was able to correctly diagnose 85.7% of the unseen cases. While this result is less than perfect, the authors acknowledge that this model is in its initial stage of development and has a future as a meaningful machine assistant to pathologists. Potentially, machine learning can be an adjunct to the other available technologies for pathologists. We should expect a growing number of studies in this arena in the next few years.

The 12-year-old boy with the heart transplant cannot hear your greeting because of the serous crusts that cake his ears. Fissures extend down to his collar and have failed to respond to our aggressive medical management. We know that switching his immunosuppression can clear his skin. We know that changing the immunosuppression regimen will trigger the burden and risks of increased biopsies of his heart to monitor for rejection. Has an alternative to heart biopsies arrived?

Recently, numerous studies have explored the significance of the circulating foreign DNA from the donated organs as a marker of rejection. The contents of ruptured cells are carried in the blood and facilitate sampling through peripheral blood draws. There is a clear correlation between organ damage and increased amounts of circulating donor DNA. The ambiguity lies in the timing of the association and the optimal protocols to monitor the blood. Does the elevation of circulating donor DNA signal the spark in the wall that starts the housefire or the smoldering embers the day after?

A recent single center report of an alternative surveillance protocol in pediatric heart transplantation patients supports the adoption of the circulating donor DNA assay to monitor for signs of transplanted organ rejection (Pediatric Transplantation. 2022; 26e14124). 58 pediatric patients were monitored over 17 months with phlebotomy performed following decreased immunosuppression or new symptoms of uncertain significance. Relying on the circulating donor DNA levels, 47 of 58 invasive endomyocardial biopsies recommended per-protocol surveillance were not performed during the study period with no deaths nor episodes of apparent graft rejection.

Our advocacy to change immunosuppression in this vulnerable population may be getting easier with the adoption of these new circulating donor DNA protocols.

Herpes simplex virus type 2 (HSV-2) has typically been the cause of genital herpes infections. However, with decreasing rates of oral HSV-1 infection during childhood, HSV-1 has emerged as an increasing cause of genital herpes.

A study published in JAMA investigated questions pertinent to genital HSV-1 infections, including rates of genital HSV-1 shedding and outbreaks following initial infection and prevalence of concurrent oral and genital HSV-1 infection.

The study enrolled 82 participants with first-episode genital HSV-1 infection, including 42 participants with primary infection (defined as no evidence of prior HSV-1 infection). Participants self-collected oral and anogenital swabs and reported oral and genital symptoms each day during months two and 11 (with no antiviral treatment during those periods).

During month two, 65% and 30% of participants had genital and oral HSV-1 detected, respectively, during at least one day, and 15% and 2% of participants reported genital and oral lesions, respectively. During month 11, 33% and 25% had genital and oral HSV-1 detected, respectively, during at least one day, and 23% and 5% reported genital and oral lesions, respectively. Shedding and lesions were generally more likely among participants with primary infections.

These results show that genital and oral HSV-1 shedding, but not lesions, is frequent after first-episode (especially primary) genital herpes infection, but declined over the year. Because shedding can lead to transmission of infection, these data inform counseling of patients regarding risk and prevention of outbreaks and transmission to partners and, in the case of pregnant persons, to neonates.

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