Defining D-irAEs: consensus-based disease definitions for the diagnosis of dermatologic adverse events from immune checkpoint inhibitor therapy.

With an increasing number of patients eligible for immune checkpoint inhibitors, the incidence of immune-related adverse events (irAEs) is on the rise. Dermatologic immune-related adverse events (D-irAEs) are the most common and earliest to manifest, often with important downstream consequences for the patient. Current guidelines lack clarity in terms of diagnostic criteria for D-irAEs. The goal of this project is to better define D-irAE for the purposes of identification, diagnosis, and future study of this important group of diseases.The objectives of this project were to develop consensus guidance for an approach to D-irAEs including disease definitions and severity grading. Knowing that consensus among oncologists, dermatologists, and irAE subspecialists would be critical for usability, we formed a Dermatologic irAE Disease Definition Panel. The panel was composed of 34 experts, including oncologists, dermatologists, a rheumatologist, and an allergist/immunologist from 22 institutions across the USA and internationally. A modified Delphi consensus process was used, with two rounds of anonymous ratings by panelists and two virtual meetings to discuss areas of controversy. Panelists rated content for usability, appropriateness, and accuracy on 9-point scales in electronic surveys and provided free text comments. A working group aggregated survey responses and incorporated them into revised definitions. Consensus was based on numeric ratings using the RAND/UCLA Appropriateness Method with prespecified definitions.Following revisions based on panelist feedback, all items received consensus in the second round of ratings. Consensus definitions were achieved for 10 core D-irAE diagnoses: ICI-vitiligo, ICI-lichen planus, ICI-psoriasis, ICI-exanthem, ICI-bullous pemphigoid, ICI-Grover's, ICI-eczematous, ICI-eruptive atypical squamous proliferation, ICI-pruritus without rash, and ICI-erosive mucocutaneous. A standard evaluation for D-irAE was also found to reach consensus, with disease-specific exceptions detailed when necessary. Each disorder's description includes further details on disease subtypes, symptoms, supportive exam findings, and three levels of diagnostic certainty (definite, probable, and possible).These consensus-driven disease definitions standardize D-irAE classification in a useable framework for multiple disciplines and will be the foundation for future work. Given consensus on their accuracy and usability from a representative panel group, we anticipate that they can be used broadly across clinical and research settings.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part II diagnosis and management.

Drug-induced hypersensitivity syndrome, also known as drug reaction with eosinophilia and systemic symptoms, is a severe cutaneous adverse reaction characterized by an exanthem, fever, and hematologic and visceral organ involvement. The differential diagnosis includes other cutaneous adverse reactions, infections, inflammatory and autoimmune diseases, and neoplastic disorders. Three sets of diagnostic criteria have been proposed; however, consensus is lacking. The cornerstone of management is immediate discontinuation of the suspected drug culprit. Systemic corticosteroids remain first-line therapy, but the literature on steroid-sparing agents is expanding. Longitudinal evaluation for sequelae is recommended. Adjunctive tests for risk stratification and drug culprit identification remain under investigation. Part II of this continuing medical education activity begins by exploring the differential diagnosis and diagnosis of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms and concludes with an evidence-based overview of evaluation and treatment.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part I. Epidemiology, pathogenesis, clinicopathological features, and prognosis.

Drug-induced hypersensitivity syndrome (DiHS), also known as drug reaction with eosinophilia and systemic symptoms (DRESS), is a severe cutaneous adverse reaction (SCAR) characterized by an exanthem, fever, and hematologic and visceral organ involvement. Anticonvulsants, antibiotics, and allopurinol are the most common triggers. The pathogenesis involves a complex interplay between drugs, viruses, and the immune system primarily mediated by T-cells. DiHS/DRESS typically presents with a morbilliform eruption 2-6 weeks after drug exposure, and is associated with significant morbidity, mortality, and risk of relapse. Long-term sequelae primarily relate to organ dysfunction and autoimmune diseases. Part I of this continuing medical education activity on DiHS/DRESS provides an update on epidemiology, novel insights into pathogenesis, and a description of clinicopathological features and prognosis.

Development of a Skin-Directed Scoring System for Stevens-Johnson Syndrome and Epidermal Necrolysis: A Delphi Consensus Exercise.

Importance: Scoring systems for Stevens-Johnson syndrome and epidermal necrolysis (EN) only estimate patient prognosis and are weighted toward comorbidities and systemic features; morphologic terminology for EN lesions is inconsistent. Objectives: To establish consensus among expert dermatologists on EN terminology, morphologic progression, and most-affected sites, and to build a framework for developing a skin-directed scoring system for EN. Evidence Review: A Delphi consensus using the RAND/UCLA appropriateness criteria was initiated with a core group from the Society of Dermatology Hospitalists to establish agreement on the optimal design for an EN cutaneous scoring instrument, terminology, morphologic traits, and sites of involvement. Findings: In round 1, the 54 participating dermatology hospitalists reached consensus on all 49 statements (30 appropriate, 3 inappropriate, 16 uncertain). In round 2, they agreed on another 15 statements (8 appropriate, 7 uncertain). There was consistent agreement on the need for a skin-specific instrument; on the most-often affected skin sites (head and neck, chest, upper back, ocular mucosa, oral mucosa); and that blanching erythema, dusky erythema, targetoid erythema, vesicles/bullae, desquamation, and erosions comprise the morphologic traits of EN and can be consistently differentiated. Conclusions and Relevance: This consensus exercise confirmed the need for an EN skin-directed scoring system, nomenclature, and differentiation of specific morphologic traits, and identified the sites most affected. It also established a baseline consensus for a standardized EN instrument with consistent terminology.

Assessing the Discriminatory Ability of Diagnostic Criteria for Ulcerative Pyoderma Gangrenosum and Its Mimickers.

This comparative effectiveness research study assesses the discriminatory ability of diagnostic criteria for pyoderma gangrenosum.

Identification of a neutrophil-specific PIK3R1 mutation facilitates targeted treatment in a patient with Sweet syndrome.

BackgroundAcute febrile neutrophilic dermatosis (Sweet syndrome) is a potentially fatal multiorgan inflammatory disease characterized by fever, leukocytosis, and a rash with a neutrophilic infiltrate. The disease pathophysiology remains elusive, and current dogma suggests that Sweet syndrome is a process of reactivity to an unknown antigen. Corticosteroids and steroid-sparing agents remain frontline therapies, but refractory cases pose a clinical challenge.MethodsA 51-year-old woman with multiorgan Sweet syndrome developed serious corticosteroid-related side effects and was refractory to steroid-sparing agents. Blood counts, liver enzymes, and skin histopathology supported the diagnosis. Whole-genome sequencing, transcriptomic profiling, and cellular assays of the patient's skin and neutrophils were performed.ResultsWe identified elevated IL-1 signaling in lesional Sweet syndrome skin caused by a PIK3R1 gain-of-function mutation specifically found in neutrophils. This mutation increased neutrophil migration toward IL-1ß and neutrophil respiratory burst. Targeted treatment of the patient with an IL-1 receptor 1 antagonist resulted in a dramatic therapeutic response and enabled a tapering off of corticosteroids.ConclusionDysregulated PI3K/AKT signaling is the first signaling pathway linked to Sweet syndrome and suggests that this syndrome may be caused by acquired mutations that modulate neutrophil function. Moreover, integration of molecular data across multiple levels identified a distinct subtype within a heterogeneous disease that resulted in a rational and successful clinical intervention. Future patients will benefit from efforts to identify potential mutations. The ability to directly interrogate the diseased skin allows this method to be generalizable to other inflammatory diseases and demonstrates a potential personalized medicine approach for patients with clinically challenging disease.Funding SourcesBerstein Foundation, NIH, Veterans Affairs (VA) Administration, Moseley Foundation, and H.T. Leung Foundation.

Stenotrophomonas maltophilia, a Pathogen of Increasing Relevance to Dermatologists: A Case Report and Review of the Literature.

Stenotrophomonas maltophilia is a Gram-negative bacillus that causes skin and soft tissue infections (SSTI), as well as bacteremia, pneumonia, and urinary tract infections. S. maltophilia infections are typically nosocomial and are often transmitted through water sources. Although historically described in immunocompromised hosts, S. maltophilia prevalence is increasing in both immunocompromised and immunocompetent populations. In light of high morbidity and mortality, it is critical that dermatologists are aware of this organism because of the limited options for therapy. Here, we describe a case of a S. maltophilia abscess with bacteremia in a patient with chronic lymphocytic leukemia and aplastic anemia that was successfully treated with trimethoprim-sulfamethoxazole. We also review the current standard of care and propose an algorithm for the treatment of S. maltophilia infection.

Mucocutaneous Leishmaniasis in a Pregnant Immigrant.

Cutaneous leishmaniasis is a parasitic infection that causes significant maternal morbidity, and even fetal mortality, during pregnancy, yet there are limited therapeutic options. Here, we report a case of leishmaniasis in a pregnant immigrant with exuberant mucocutaneous lesions with favorable response to liposomal amphotericin B.

Risk Factors for the Development of Bullous Pemphigoid in US Patients Receiving Immune Checkpoint Inhibitors.

Importance: De novo bullous pemphigoid (BP) is a rare immune-mediated adverse event from immune checkpoint inhibitors (ICIs) that can necessitate permanent discontinuation of the anticancer therapy, but the risk factors for developing this toxic effect are unknown. Objective: To compare potential risk factors for BP in patients treated with ICIs who did and did not develop BP. Design, Setting, and Participants: This cohort and nested propensity score-matched case-control study was conducted at the Dana-Farber Cancer Institute, Brigham and Women's Hospital, and Massachusetts General Hospital. All patients at these facilities with de novo BP after ICI treatment were compared with all patients on the cancer registry who were treated with ICIs between October 1, 2014, and December 31, 2020. Patients with incomplete or blinded data regarding the ICI agent or total cycles were excluded. Exposures: In the cohort, assessed potential risk factors included age at ICI introduction, sex, ICI molecular target, and cancer type, which were then used as matching variables. In the propensity score-matched case-control analysis, risk factors assessed included sex, race and ethnicity, cancer stage, metastasis sites, idiopathic BP comorbidities, pre-ICI vaccination, radiation history, body mass index, and derived neutrophil-to-lymphocyte ratio. Main Outcomes and Measures: Diagnosis of BP at any point after ICI treatment, confirmed by direct immunofluorescence, indirect immunofluorescence, autoantibody serologies, or diagnostic consensus among study board-certified dermatologists. Odds ratios (ORs) and 95% CIs were calculated for all risk factors. In the secondary analysis, best overall responses to ICIs between cases and controls were compared by Fisher exact test. Results: Among 5636 patients treated with ICIs at Dana-Farber Cancer Institute, Brigham and Women's Hospital, and Massachusetts General Hospital during the study period, 35 (0.6%; median [IQR] age, 72.8 [13.4] years; 71.4% [25] male patients) developed BP. In a multivariate logistic regression model that assessed 2955 patients with complete data in the cancer registry, age 70 years or older (OR, 2.32; 95% CI, 1.19-4.59; P = .01), having melanoma (OR, 3.21; 95% CI, 1.51-6.58; P < .003), and having nonmelanoma skin cancer (OR, 8.32; 95% CI, 2.81-21.13; P < .001) were significantly associated with developing BP. In the nested 1:2 case-control comparison of all 35 cases to 70 propensity score-matched controls, a complete or partial response on initial restaging imaging was a risk factor for BP development (OR, 3.37; 95% CI, 1.35-9.30; P = .01). Bullous pemphigoid cases also more frequently exhibited overall tumor response to ICIs than matched controls (29 of 35 [82.9%] vs 43 of 70 [61.4%]; P = .03). Conclusions and Relevance: In this cohort study, age 70 years or older and skin cancer were associated with increased risk of developing ICI-associated BP. Given the association of BP with improved initial and best overall tumor responses, early identification and toxic effect-directed treatment should be prioritized, especially in individuals at risk for developing de novo BP.

Neutrophilic Dermatoses: a Clinical Update.

Purpose of Review: Neutrophilic dermatoses are defined by the presence of a sterile neutrophilic infiltrate on histopathology. This review focuses on the pathogenesis, epidemiology, clinicopathological features, diagnosis, and management of four disorders: Sweet syndrome, pyoderma gangrenosum, Behçet syndrome, and neutrophilic eccrine hidradenitis. Recent Findings: Recent studies have provided insight into the complex pathogenesis of neutrophilic dermatoses. Evidence supports an intricate interplay of abnormal neutrophil function and inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic predisposition. Summary: Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, and neoplastic disorders, as well as drug reactions. Emerging diagnostic and therapeutic frameworks identify an expanding role for biologic and targeted anti-inflammatory therapies.

Development and Initial Validation of a Novel System to Assess Ichthyosis Severity.

IMPORTANCE: A comprehensive, user-friendly system to assess global ichthyosis disease burden is imperative to improving the care of patients with ichthyosis, identifying appropriate participants for clinical trials, and quantifying treatment outcomes. To our knowledge, there is currently no validated scale to objectively and systematically measure ichthyosis severity across the entire body. OBJECTIVE: To create and evaluate a comprehensive and user-friendly instrument to measure total body ichthyosis severity in adults and children. DESIGN, SETTING, PARTICIPANTS: In this qualitative study, ichthyosis experts participated in the content development of the Ichthyosis Scoring System (ISS). The body was divided into 10 regions, and Likert scales (0-4) were created to quantify scale and erythema, with extensive descriptors and photographic standards. An 83-image teaching set was created from photographs of participants with ichthyosis. Two cohorts of dermatologists (11 total) independently scored all test photographs twice to evaluate interrater and intrarater reliabilities. Participants were enrolled worldwide from referral centers and patient advocacy groups. Participants of all ages, races, and ethnicities were included in the creation of ISS, and dermatologists with varying experience and areas of expertise participated as raters to evaluate the ISS. The study was conducted from 2019 to 2021, and the data were analyzed in 2021. MAIN OUTCOMES AND MEASURES: Intraclass correlation coefficients determined overall reliabilities. RESULTS: Across both cohorts of 11 dermatologists in total, the intraclass correlation coefficients for total, scale and erythema scores were greater than 0.90 (95% CI, 0.77-0.97), greater than 0.91 (95% CI, 0.79-0.98), and greater than 0.88 (95% CI, 0.72-0.97), respectively. Most body sites exhibited moderate to good interrater reliabilities for scale and erythema. Intrarater reliabilities were good to excellent. CONCLUSIONS AND RELEVANCE: The results of this qualitative study demonstrate reproducibility and suggest that the ISS is a reliable system to measure global ichthyosis severity in adults and children.

Clinical Characteristics, Disease Course, and Outcomes of Patients With Acute Generalized Exanthematous Pustulosis in the US.

Importance: Acute generalized exanthematous pustulosis (AGEP) is a rare, severe cutaneous adverse reaction associated with systemic complications. Currently available data are largely limited to small retrospective case series. Objective: To describe the clinical characteristics, disease course, and outcomes of a heterogeneous group of patients with AGEP across the US. Design, Setting, and Participants: A retrospective review of a case series of patients was conducted from January 1, 2000, through July 31, 2020. All 340 included cases throughout 10 academic health systems in the US were scored retrospectively using the EuroSCAR scoring system, and patients with a score corresponding to probable or definite AGEP and aged 18 years or older were included. Main Outcomes and Measures: Patient demographic characteristics, clinical course, suspected causative agent, treatment, and short- and long-term outcomes. Results: Most of the 340 included patients were women (214 [62.9%]), White (206 [60.6%]), and non-Hispanic (239 [70.3%]); mean (SD) age was 57.8 (17.4) years. A total of 154 of 310 patients (49.7%) had a temperature greater than or equal to 38.0 °C that lasted for a median of 2 (IQR, 1-4) days. Of 309 patients, 263 (85.1%) developed absolute neutrophilia and 161 patients (52.1%) developed either absolute or relative eosinophilia. Suspected causes of AGEP were medications (291 [85.6%]), intravenous contrast agents (7 [2.1%]), infection (3 [0.9%]), or unknown (39 [11.5%]). In 151 cases in which a single medication was identified, 63 (41.7%) were ß-lactam antimicrobials, 51 (33.8%) were non-ß-lactam antimicrobials, 9 (6.0%) were anticonvulsants, and 5 (3.3%) were calcium channel blockers. The median time from medication initiation to AGEP start date was 3 (IQR, 1-9) days. Twenty-five of 298 patients (8.4%) had an acute elevation of aspartate aminotransferase and alanine aminotransferase levels, with a peak at 6 (IQR, 3-9) days. Twenty-five of 319 patients (7.8%) experienced acute kidney insufficiency, with the median time to peak creatinine level being 4 (IQR, 2-5) days after the AGEP start date. Treatments included topical corticosteroids (277 [81.5%], either alone or in combination), systemic corticosteroids (109 [32.1%]), cyclosporine (10 [2.9%]), or supportive care only (36 [10.6%]). All-cause mortality within 30 days was 3.5% (n = 12), none of which was suspected to be due to AGEP. Conclusions and Relevance: This retrospective case series evaluation of 340 patients, the largest known study cohort to date, suggests that AGEP onset is acute, is usually triggered by recent exposure to an antimicrobial, may be associated with liver or kidney complications in a minority of patients, and that discontinuation of the triggering treatment may lead to improvement or resolution.