Sartori‐Valinotti, Julio C.

Introduction: Limited research explores dermoscopy use among physician associates (PAs), outside of one prior study examining dermoscopy in PA student education. This study sought to investigate dermoscopy use among practicing PAs and its impact on their overall diagnostic confidence, including in darker skin tones, when differentiating between benign and malignant skin lesions. Methods: An anonymous survey was developed in 2023 with input from experts in dermoscopy and survey creation to assess PA confidence in skin lesion evaluation as well as PA dermoscopy knowledge and use, perceptions, barriers to use, and prior education. The dermoscopy survey was included as an optional module in the 2024 American Academy of Physician Associates (AAPA) Salary Survey. Results: Of 3,174 invited PAs, 995 (31.4%) responded. Most had never used dermoscopy in practice (81%) but knew or recognized the term (71%). A majority (53%) believed PAs should be trained in dermoscopy during PA school, and 26% reported no interest in future dermoscopy use. Dermatology PAs reported more frequent dermoscopy use and generally greater confidence in evaluating skin lesions, both overall and in darker skin tones, than PAs in other specialties. PAs in surgical (OR=0.2, 95% CI 0.1-0.6) and medical (OR=0.3, 95% CI 0.2-0.5) subspecialties were less likely to use dermoscopy at least annually compared with PAs in primary care. PAs in rural areas were more likely to feel confident in differentiating skin lesions than those in urban areas (OR 2.9, 95% CI 1.7-5.0). Conclusion: Dermoscopy use is associated with higher overall skin lesion assessment confidence. Wider adoption, especially outside dermatology, requires training, increased advocacy, and expanded education.

Abstract Erdheim-Chester disease (ECD) is a rare systemic histiocytic neoplasm, with cardiac morbidities, including cardiovascular (CV) risk factors and cardiac conditions, playing a significant yet poorly understood role in the disease burden. This study evaluated the prevalence, characteristics, and prognosis of ECD in patients with (ECD-C) and without cardiac involvement (ECD-noC) and compared the burden of cardiac morbidities with matched controls. Patients diagnosed with ECD between 1990 and 2021 at a tertiary center were included, with cardiac involvement centrally assessed using radiographic studies. Cardiac morbidities were compared with a control group without ECD, matched for age, sex, body mass index, and smoking history. Among 104 patients with ECD, 39 (37%) had cardiac involvement. Patients with ECD-C had higher rates of hypertension (67% vs 46%), hyperlipidemia (67% vs 40%), heart failure (36% vs 8%), and pericardial effusion (28% vs 2%) than those with ECD-noC. Compared with the matched non-ECD cohort, patients with ECD had higher prevalence of coronary artery disease (20% vs 7%), heart failure (18% vs 4%), and antihypertensive drug use (55% vs 40%). Notably, patients with ECD-C had inferior progression-free survival (PFS) from frontline therapy compared with patients with ECD-noC (5-year PFS, 28.3% vs 70.5%). These findings highlight the burden of CV risk factors and cardiac conditions in ECD, even without a clinical diagnosis of ECD-C. Importantly, this cardiac morbidity burden is substantial for patients with ECD-C compared with ECD-noC. Our findings highlight the need for comprehensive cardiac risk assessment and management strategies to improve patient outcomes.

ABSTRACTBackgroundDrug‐induced hypersensitivity syndrome (DiHS), or drug reaction with eosinophilia and systemic symptoms (DRESS), is a delayed and severe immune response to certain medications. We investigated vancomycin‐induced DiHS/DRESS, notable for frequent and severe organ involvement, to describe its specific histopathology and the correlations between histopathologic and clinical findings.MethodsA retrospective review was conducted to identify patients between 2006 and 2022 who received vancomycin, had archived skin biopsy specimens, and were scored as having probable or definite DiHS/DRESS. Clinical features were retrospectively collected, and biopsy specimens were reviewed by a board‐certified dermatopathologist. A subset of histopathologic and clinical features was analyzed for statistical correlation.ResultsTwenty‐three patients met the inclusion criteria. Most biopsy specimens (87%) showed an eczematous reaction pattern; 17 (74%) showed a secondary reaction pattern. Spongiosis (87%) and neutrophilic infiltration (91%) were common epidermal characteristics. The dermal inflammatory infiltrate was frequently superficial (87%) and consistently included plasma cells (96%). Eosinophils were present in the dermis in 70% of cases. Parakeratosis negatively correlated with liver involvement and positively correlated with desquamative rash. Epidermal lymphocytes were negatively correlated with the RegiSCAR score.ConclusionsVancomycin‐associated DiHS/DRESS histopathology was characterized by a frequent eczematous reaction pattern, multiple coexisting reaction patterns, and epidermal neutrophilic infiltration.

Background: Erdheim-Chester disease (ECD) manifests as multi-organ infiltration of clonal histiocytes with mutations primarily in the mitogen-activated protein kinase (MAPK) pathway. The revised classification of histiocytosis (2016) categorizes ECD with typical bilateral, symmetric osteosclerosis of the lower extremity long bones as classical (C) and as non-classical (NC) if otherwise. The clinical and biological significance of this classification is unclear. This study compared the clinical and genotypic findings of the 2 subtypes within a large cohort of ECD patients. Methods: We included patients seen at our institution since 1990 meeting the following criteria: A) had an ECD diagnosis based on the revised criteria by Haroche J, et al. (Blood 2020;135:1311-1318); B) completed whole-body imaging studies including long bones of the legs. Classification as C-ECD required symmetric osteosclerosis of the distal femur and/or proximal tibia/fibula. Results: A total of 145 patients were enrolled, comprising a male-to-female ratio of 2:1 (66.2% male). C-ECD was diagnosed in 77.2% of cases, and NC-ECD in 22.8%. The median age at diagnosis was similar with 58.5 years (range, 18-82) in C-ECD and 55 years (range, 20-81) in NC-ECD, (p=0.65). The most frequently affected systems included skeletal (81.4%), renal (60.0%), vascular (45.5%), cardiac (40.0%), central nervous (38.6%), sinus (37.2%), pulmonary (36.6%), and adrenal (32.4%). The numbers of organs involved were significantly higher in C-ECD compared to NC-ECD (median 5 vs 3, p<0.01). Higher rates of skeletal (100% vs. 18.2%, p<0.01), adrenal gland (37.5% vs. 15.2%, p=0.02), and sinus (44.6% vs. 12.1%, p<0.01) involvement were observed in C-ECD. Arginine vasopressin deficiency (AVP-D) was exclusively observed in C-ECD (20.7% vs. 0%, p<0.01). NC-ECD had a higher rate of cardiac involvement (69.7% vs. 31.3%, p<0.01). No significant differences were found in other systems. The overall median time between onset of the first symptoms/signs to diagnosis was 15 months with no significant difference between C-ECD and NC-ECD (17.5 vs. 12 months, p=0.18). The median time to diagnosis of ECD in patients with AVP-D was 38.5 months, compared to 12 months without AVP-D (p=0.09). Genetic testing was conducted in 86.2% of patients and B-Raf proto-oncogene (BRAF) alterations were identified in 59.2% of the tested cases. BRAFV600E was more prevalent in C-ECD (61.3% vs. 21.9%, p<0.01), whereas non-V600 mutations were more commonly found in NC-ECD (12.5% vs. 1.1%, p<0.01). There was no significant difference in the frequency of BRAF fusions. NC-ECD patients exhibited a higher rate of MAP2K1 mutations (25.0% vs. 5.4%, p<0.01). Other frequently mutated genes included KRAS (4.0%), NRAS (2.4%), and CSF1R (2.4%), although no significant difference was observed in their frequency between C-ECD and NC-ECD. Testicular involvement appeared to be more common in patients with MAP2K1 mutations (23.1% vs. 8%, p=0.08). Two patients with pathogenic CSF1R mutations both had central nervous system (CNS) involvement. Among C-ECD patients, BRAFV600E conferred a higher rate of CNS involvement (50.9% vs. 25%, p=0.01). No significant difference was observed in NC-ECD patients (71.4% vs 36%, p=0.09). Among NC-ECD cases, MAP2K1 mutations conferred a reduced risk of cardiac involvement (37.5% vs. 79.2%, p=0.03) and no such difference was observed in patients with C-ECD (40% vs 34.1%, p=0.79). The median numbers of organs involved in patients with BRAF, MAP2K1, and KRAS/NRAS mutations were 5, 3, and 3, respectively, with no significant difference. Conclusions: C-ECD affects more organs and more frequently involves bones, adrenal glands, and sinuses. AVP-D was exclusively observed in C-ECD. Conversely, NC-ECD showed a higher prevalence of cardiac involvement. BRAFV600E was more commonly identified in C-ECD, whereas non-V600 mutations and MAP2K1 mutations were more prevalent in NC-ECD. Among C-ECD patients, BRAFV600E was correlated with a greater likelihood of CNS involvement. Conversely, NC-ECD patients with MAP2K1 mutations had a reduced risk of cardiac involvement. This study highlights the distinct clinical and molecular features of C-ECD and NC-ECD, underscoring the importance of subclassifying ECD into classical and non-classical forms. Further studies are needed to explore differences in the clinical outcomes between the 2 forms.

PURPOSE BRAF and MEK inhibitors are standard treatments in histiocytic disorders, such as Erdheim-Chester disease (ECD). Some patients lack MAPK-pathway alterations, making these treatments less effective. METHODS We describe three patients with histiocytic disorders who have novel non-MAPK pathway alterations. These alterations were studied through genomic and in silico analyses when applicable, then treated with off-label medications rationally selected on the basis of genomic alterations. RESULTS Patient 1 had rapidly progressive ECD involving the CNS. A CSF1R in-frame deletion (p.S560_P566del) was identified, and in silico modeling predicted a gain-of-function mutation. This alteration was targeted with pexidartinib, which led to a clinical complete response (CR) within 2 months, and a partial response (PR) on imaging after 3 months. After 15 months, the disease became resistant to pexidartinib and transformed to histiocytic sarcoma. Patient 2 has skin-only involvement of a xanthogranuloma disorder. A KIF5B-FGFR1 fusion was identified on RNA sequencing and targeted with pemigatinib. At 24 months of follow-up, she remains in a clinical PR. Patient 3 has ECD involving the bone marrow, gastrointestinal tract, and subcutaneous tissues. A MEF2C-FLT3 fusion was identified and targeted with sorafenib. He achieved a clinical CR and radiographic PR within 3 months, which has continued for 30 months. CONCLUSION We report three patients with histiocytic disorders harboring novel alterations who had sustained responses to off-label kinase inhibitors specific to their histiocytic disorder. Pathogenic variants outside of the MAPK pathway, including variants of unknown significant, may be targeted with readily available small molecules.

Background: Proper diagnosis in primary care is crucial due to the large number of skin cancer diagnoses each year and its associated growing economic burden. Understanding how primary care providers can be best trained in dermoscopy is instrumental in helping primary care providers differentiate benign and malignant cutaneous lesions so that appropriate action can be taken (eg, biopsy/referral to dermatology or reassurance). Objective: To assess the success of concise dermoscopy training among primary care providers. Design: A cohort study was conducted in primary care at Mayo Clinic, Rochester, including primary care physicians, nurse practitioners, and physician assistants in internal medicine and family medicine. Diagnostic accuracy was measured on standardized testing through image-based recognition and in clinical practice through observation of referral and biopsy patterns both before and after dermoscopy education, focused on the TADA plus method. Results: Forty-three primary care providers completed the image-based recognition tests, with significant improvement in mean score measured after dermoscopy training workshop (20%). Among the thirteen primary care providers who continued to use dermoscopy in clinical practice, a significant improvement (31%) in mean clinical diagnostic accuracy was observed comparing 1 year of practice data before versus after dermoscopy training. Conclusion: Improvement in diagnostic accuracy with utilization of the TADA plus method translates into clinical practice. Therefore, training primary care providers in dermoscopy may improve the dermatologic care patients receive in primary care, especially in rural or medically underserved areas where access to dermatology is limited.

Abstract Objectives To define the prevalence, distribution and characteristics of patients with VEXAS (vacuoles, E1-enzyme, X-linked, autoinflammation, somatic) syndrome who have confirmed vasculitis. Methods Patients with VEXAS syndrome, verified by positive UBA1 mutation, were included. Chart review was performed to identify patient characteristics and outcomes. Vasculitis diagnosis was based on either histopathology showing vascular inflammation or non-invasive angiography findings. Summary statistics were calculated. Results Eighty-nine patients met inclusion criteria. All were male with a median age of onset of 66.9 years (interquartile range 60.1, 72.7). Median (interquartile range) follow-up was 3.8 (2.2–5.5) years, during which 21 patients (23.6%) had evidence of vasculitis. Vasculitis subtypes included small vessel vasculitis (19.1%), cutaneous medium vessel vasculitis (2.2%) and large vessel vasculitis (2.2%). No patient had more than one vessel size involved. Histopathology in small vessel vasculitis patients was consistent with cutaneous leukocytoclastic vasculitis in the majority, though one patient had leukocytoclastic peritubular capillaritis on renal biopsy. Cranial symptoms (headache, vision changes or jaw pain) were noted in 18.0%. Two additional patients not experiencing cranial symptoms exhibited large vessel involvement with confirmed carotid thickening on non-invasive angiography; one of these had a positive temporal artery biopsy. Conclusion VEXAS syndrome manifests as a variable vessel vasculitis in a quarter of patients, with cutaneous small and medium vessel involvement being particularly common. Some patients may have positive ANCA serologies or even renal vasculitis leading to misdiagnosis. Cranial symptoms are common and may mimic GCA, though documented large vessel inflammation is rare.

Erythromelalgia is a rare disorder characterized by episodic burning pain with redness and warmth of the extremities. Topical and systemic medications are the mainstay of management. We reviewed the published evidence for using procedural interventions to manage erythromelalgia, including their proposed mechanism of action and possible adverse effects, and included information in this review on epidural infusion, sympathetic ganglion block, sympathectomy, pulsed radiofrequency, spinal cord stimulation, dorsal root ganglion stimulation, brain stimulation, transcranial magnetic stimulation, and botulinum toxin injections. Both successful and unsuccessful outcomes have been reported. Although these procedural interventions extend the therapeutic options for erythromelalgia, the evidence for their use is limited. Case reports and small case series comprise most of the evidence. Based on our review, a multidisciplinary approach to management may be needed for patients with erythromelalgia.