Faculty Bibliography

BACKGROUND/UNASSIGNED:Diffuse unpatterned alopecia (DUPA) is an uncommon and incompletely characterized variant of androgenetic alopecia (AGA) marked by diffuse follicular miniaturization across the entire scalp, including the occipital region, which distinguishes it from classic patterned AGA and often precludes hair transplantation. SUMMARY/UNASSIGNED:In this review of the available literature on DUPA, we discuss its clinical presentation, diagnostic features, competing pathophysiologic hypotheses, and management considerations. Current evidence suggests DUPA typically presents with diffuse thinning across all scalp regions, with trichoscopy demonstrating widespread follicular miniaturization without features of scarring alopecia. Diagnosis remains clinical because histopathologic criteria and standardized trichometric thresholds have not been established. Important mimickers include telogen effluvium and diffuse alopecia areata, requiring careful history, examination, trichoscopy, and occasional scalp biopsy. Management is primarily medical, emphasizing stabilization rather than regrowth, and includes topical or oral minoxidil with consideration of adjunctive therapies in selected patients. KEY MESSAGES/UNASSIGNED:DUPA is a diffuse, non-patterned hair loss condition affecting the entire scalp, including the occipital region, for which medical management remains the cornerstone of treatment. DUPA remains poorly defined and further clinicopathologic, trichometric, and longitudinal studies are needed to clarify major knowledge gaps, including epidemiology, pathology, diagnostic criteria, and treatment-specific outcomes.

Allergic contact dermatitis (ACD) to personal care products (PCPs) represents a significant and growing clinical challenge, with increasing use of diverse PCPs and their expanding range of ingredients. Common allergenic components include fragrances, botanicals, preservatives, surfactants, emollients, emulsifiers, vitamins, and ultraviolet (UV) filters. Patch testing remains the gold standard for diagnosing ACD and identifying causative allergens, but traditional panels often fail to capture emerging PCP-related allergens. This review highlights key established and emerging PCP allergens, such as limonene and linalool hydroperoxides, sodium benzoate, octocrylene, and benzophenone-4. Strategies are discussed to optimize diagnostic accuracy through targeted series and repeated open application tests. Patient education about PCP labeling is paramount when assisting patients with allergen avoidance. Clinicians must balance precise allergen identification with practical management knowledge to improve outcomes in PCP-related ACD.

Mucous membrane pemphigoid (MMP) is an autoimmune blistering disorder that can involve the esophagus, potentially leading to complications such as stricture or stenosis. Diagnosis of MMP is challenging owing to overlapping clinical features with other subepithelial blistering diseases and limitations of current diagnostic techniques. Although direct immunofluorescence (DIF) remains the gold standard, it requires fresh tissue samples, which are not always available, particularly in cases without active mucosal or cutaneous lesions. Complement fragment 4d (C4d) immunohistochemistry (IHC) on formalin-fixed tissue has demonstrated diagnostic utility in bullous pemphigoid but has been less explored in MMP. This case highlights that C4d IHC may serve as a useful ancillary test to support MMP diagnosis, especially for mucosal or esophageal biopsies received in formalin, offering a potential diagnostic pathway when fresh biopsy samples are unavailable.

Epstein-Barr virus (EBV) plays a role in the pathogenesis of a wide variety of acute and chronic diseases. Cutaneous manifestations of EBV include exanthems, chronic infections, malignancies, and small vessel vasculitides. Clinically and histologically, many of these conditions can imitate each other, making diagnosis challenging. In this report, we present a case of a child who developed Gianotti-Crosti syndrome with histopathologic features of anti-neutrophil cytoplasmic antibody (ANCA) vasculitis in the setting of acute EBV infection. Furthermore, we review the literature on EBV-induced cutaneous small vessel vasculitis and discuss pathogenic mechanisms.

Accessing high-quality, open-access dermatopathology image datasets for learning and cross-referencing is a common challenge for clinicians and trainees. To establish a comprehensive open-access dermatopathology dataset for educational, cross-referencing, and machine-learning purposes, we employed a hybrid workflow to curate and categorize images from the PubMed Central (PMC) repository. We used specific keywords to extract relevant images, and classified them using a novel hybrid method that combined deep learning-based image modality classification with figure caption analyses. Validation on 651 manually annotated images demonstrated the robustness of our workflow, with an F-score of 89.6% for the deep learning approach, 61.0% for the keyword-based retrieval method, and 90.4% for the hybrid approach. We retrieved over 7,772 images across 166 diagnoses and released this fully annotated dataset, reviewed by board-certified dermatopathologists. Using our dataset as a challenging task, we found the current image analysis algorithm from OpenAI inadequate for analyzing dermatopathology images. In conclusion, we have developed a large, peer-reviewed, open-access dermatopathology image dataset, DermpathNet, which features a semi-automated curation workflow.