Faculty Bibliography

IMPORTANCE/UNASSIGNED:Direct immunofluorescence (DIF) testing has been an important ancillary tool for the diagnosis of various inflammatory mucocutaneous conditions for more than 50 years. Current DIF test panels are based on historical clinical descriptions; few studies have rigorously addressed preanalytical, analytical, and/or postanalytical aspects, and even fewer have been replicated or validated. Recent unresolved key issues include whether DIF testing and test panels should be triaged or truncated based on clinical indication or histopathologic findings. OBJECTIVE/UNASSIGNED:To assess levels of consensus regarding practical aspects of DIF testing among immunodermatology testing specialists in the US. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:Using modified Delphi methods with a priori characterized criteria, a survey containing 54 statements pertaining to DIF testing was created and distributed to assess consensus. Statements not initially reaching consensus were discussed in 2 live virtual sessions, which were supplemented by relevant literature review and free-text survey comments. These statements were then reassessed in a second survey. Immunodermatology testing specialists in US academic institution-based and independent laboratories were invited based on serving as immunodermatology laboratory medical directors, authoring pertinent literature, or delivering relevant talks at major conferences or by referral. The first survey was conducted from January to February 2024, and the second survey was conducted from March to April 2024. MAIN OUTCOMES AND MEASURES/UNASSIGNED:The primary measured outcome was degree of consensus for various DIF testing practice, including DIF testing triage by histopathology/dermatopathology findings and DIF testing panel tailored truncations by clinical indication. RESULTS/UNASSIGNED:A total of 23 respondents to the survey invitation had a mean (SD) of 18.5 (11.1) years and median (range) of 20.0 (1.5-46.0) years in immunodermatology laboratory practice. Consensus was achieved for 46 of 54 statements (85.2%) in the initial survey and for an additional 4 statements in the second survey (50 of 54 [92.6%]). Strong consensus was found against tailored truncation of DIF panel based on the clinical indication in the first survey round. The general acceptability of triaging specimens for DIF testing based on histopathology findings remained without consensus after both surveys. CONCLUSIONS AND RELEVANCE/UNASSIGNED:Overall, participating US specialists in immunodermatology laboratory testing agreed on many practical aspects of DIF testing, including matters not queried previously. The findings also revealed areas of continued controversy and identified issues for prioritized future study.

BACKGROUND:As more people become vaccinated against the SARS-CoV-2 virus, reports of delayed cutaneous hypersensitivity reactions are beginning to emerge. METHODS:In this IRB-approved retrospective case series, biopsies of potential cutaneous adverse reactions from the Pfizer-BioNTech or Moderna mRNA vaccine were identified and reviewed. Clinical information was obtained through the requisition form, referring clinician, or medical chart review. RESULTS:Twelve cases were included. Histopathological features from two injection site reactions showed a mixed-cell infiltrate with eosinophils and a spongiotic dermatitis with eosinophils. Three biopsies came from generalized eruptions that demonstrated interface changes consistent with an exanthematous drug reaction. Three biopsies revealed a predominantly spongiotic pattern, consistent with eczematous dermatitis. Small vessel vascular injury was seen in two specimens, which were diagnosed as urticarial vasculitis and leukocytoclastic vasculitis, respectively. There were two cases of new-onset bullous pemphigoid supported by histopathological examination and direct immunofluorescence studies. Eosinophils were seen in 10 cases. CONCLUSIONS:Dermatopathologists should be aware of potential cutaneous adverse reactions to mRNA-based COVID-19 vaccines. Histopathological patterns include mixed-cell infiltrates, epidermal spongiosis, and interface changes. Eosinophils are a common finding but are not always present. Direct immunofluorescence studies may be helpful for immune-mediated cutaneous presentations such as vasculitis or bullous pemphigoid. This article is protected by copyright. All rights reserved.

ABSTRACT/UNASSIGNED:Papillary dermal elastolysis has been described in the setting of experimental combination nivolumab and cabiralizumab immunotherapy. We report a third patient with distinctive, generalized atrophic macules that developed after a morbilliform eruption during a clinical trial for treatment of metastatic pancreatic adenocarcinoma. Histopathological findings demonstrated diminished elastic fibers in the papillary dermis, associated with a histiocyte-rich infiltrate and increased dermal mucin, features that should clue the dermatopathologist to this condition.