Reactive Granulomatous Dermatitis: A Descriptive Study of 10 Patients.

BACKGROUND: Reactive granulomatous dermatitis (RGD) is a rare and misunderstood skin disorder. It includes interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: 2 entities of the same spectrum. Multiple associations are described with RGD in the literature, including autoimmune diseases, malignancy, and drugs. OBJECTIVE: To report and describe the suspected associations with RGD at the time of diagnosis and in the following year. METHODS: We retrieved and described cases of RGD confirmed by skin biopsy and clinicopathologic correlation. All patients were evaluated in the Centre Hospitalier Universitaire de Québec-Université Laval between January 2000 and December 2020. Collected data include the systemic diseases (autoimmune disease, malignancy) and suspected drugs, in addition to the clinical presentation and prescribed treatments. RESULTS: Out of the 10 patients with RGD, 7 patients were known to have an autoimmune disease at the time of diagnosis. They either had inflammatory arthritis (3/10) or inflammatory bowel disease (4/10). There was a clinical suspicion of a possible association with a tumor necrosis factor (TNF) inhibitor in 2 of these 7 patients. Among the 3 patients with idiopathic RGD at the time of diagnosis, 1 patient developed a high-grade B-cell lymphoma 6 months later. There was no new association identified in the following year for patients with a known autoimmune condition. CONCLUSION: This descriptive study supports RGD and its previously described systemic associations, particularly autoimmune diseases, malignancy, and certain drugs (specifically TNF inhibitors). The majority of patients already had one of these associations identified at the time of histopathological diagnosis.

Granulomatous dermatitis caused by Exserohilum mcginnisii infection in a cow.

A 5-y-old, Piedmontese cow had a 4-mo history of ongoing development of skin masses. This was the only cow affected in a herd of 20 cows. Up to 12, hairless, red-to-black, raised nodules-to-plaques were distributed along the dorsum and tail head. Biopsies were taken for histopathology and ancillary testing. An ulcerated skin section contained dermal infiltrates of eosinophils, plasma cells, neutrophils, macrophages, lymphocytes, and multinucleate giant cells, and pyogranulomas. Fungal hyphae were seen within the dermis, multinucleate giant cells, and pyogranulomas. In pyogranulomas, fungi were surrounded by a Splendore-Hoeppli reaction. Dematiaceous (pigmented) hyphae were rarely observed with H&E-stained and unstained (cleared and mounted) sections, but stained well with a Fontana-Masson stain. Exserohilum mcginnisii was identified by fungal culture, followed by PCR assay and sequencing. Exserohilum is a dematiaceous fungus that causes disease in humans and rarely in animals. The use of unstained sections and Fontana-Masson stain are important to demonstrate pigment because dematiaceous fungi have little melanin and appear as hyaline hyphae histologically. PCR assay and sequencing aid in the differentiation and classification of fungal species. To our knowledge, E. mcginnisii dermal granulomas have not been reported previously in cattle.

Descriptive and Concordance Data for Asynchronous Teledermatology Consultations for Dermatitis: A Retrospective Study.

Background: Implementation of teledermatology for assessing dermatitis patients provides comparable diagnostic and management outcomes to in-person visits, but studies on consumer to physician asynchronous teledermatology (eDerm) consults submitted by patients in large dermatitis cohorts are limited. The objective of this study was to retrospectively assess associations of eDerm consults with diagnostic accuracy, management, and follow-up in a large cohort of dermatitis patients. Methods: One thousand forty-five eDerm encounters between April 1, 2020, and October 29, 2021, recorded in the University of Pittsburgh Medical Center Health System Epic electronic medical record were reviewed. Descriptive statistics and concordance were analyzed using chi-square. Results: Asynchronous teledermatology modified/changed treatment in 97.6% of cases and had the same diagnosis between teledermatology and in-person follow-up in 78.3% of cases. Patients following up in the time line requested were more likely to follow-up in person (61.2% vs. 43.8%) than those who did not. Patients with intertriginous dermatitis (p = 0.003), preexisting conditions (p = 0.002), who required follow-ups (<0.0001), and moderate-high severity scores of 4-7 (p = 0.019) were more likely to follow up in the time line requested. Limitations: Lack of similar in-person visit data did not allow us to compare descriptive and concordance data between eDerm and clinic visits. Conclusions: eDerm offers a quick accessible solution to provide comparable dermatologic care for patients with dermatitis.

Computer vision model for the detection of canine pododermatitis and neoplasia of the paw.

BACKGROUND: Artificial intelligence (AI) has been used successfully in human dermatology. AI utilises convolutional neural networks (CNN) to accomplish tasks such as image classification, object detection and segmentation, facilitating early diagnosis. Computer vision (CV), a field of AI, has shown great results in detecting signs of human skin diseases. Canine paw skin diseases are a common problem in general veterinary practice, and computer vision tools could facilitate the detection and monitoring of disease processes. Currently, no such tool is available in veterinary dermatology. ANIMALS: Digital images of paws from healthy dogs and paws with pododermatitis or neoplasia were used. OBJECTIVES: We tested the novel object detection model Pawgnosis, a Tiny YOLOv4 image analysis model deployed on a microcomputer with a camera for the rapid detection of canine pododermatitis and neoplasia. MATERIALS AND METHODS: The prediction performance metrics used to evaluate the models included mean average precision (mAP), precision, recall, average precision (AP) for accuracy and frames per second (FPS) for speed. RESULTS: A large dataset labelled by a single individual (Dataset A) used to train a Tiny YOLOv4 model provided the best results with a mean mAP of 0.95, precision of 0.86, recall of 0.93 and 20 FPS. CONCLUSIONS AND CLINICAL RELEVANCE: This novel object detection model has the potential for application in the field of veterinary dermatology.

Myelodysplasia cutis masquerading as granulomatous dermatitis.

Myelodysplastic syndromes (MDS) are a group of clonal hematopoietic neoplasms resulting from mutations in stem cells. They carry a risk of transformation to acute myeloid leukemia. Cutaneous manifestations of MDS, including myelodysplasia cutis or infiltration by MDS tumor cells, are rare, but significantly associated with increased risk of progression to high-grade myeloid tumors. The clinical and histopathologic differential diagnosis for myelodysplasia cutis includes interstitial granulomatous dermatitis (IGD), a reactive granulomatous dermatitis (RGD) associated with systemic diseases including rheumatologic diseases, and hematologic malignancy like MDS. We report a patient with MDS who presented with myelodysplasia cutis masquerading as IGD both in a clinical and histopathological manner.

Amicrobial pustulosis of the folds: A case report of a rare variant of neutrophilic dermatosis associated with systemic lupus erythematosus.

Amicrobial pustulosis of the folds (APF) is a rare neutrophilic dermatosis found in association with autoimmune diseases. We present a 49-year-old woman with a history of systemic lupus erythematosus and a recurrent pustular eruption in the cutaneous folds. Histologic examination revealed spongiform pustulosis and dermal neutrophilic infiltrate. The Gram and periodic acid-Schiff stains were negative for bacteria and fungi. A diagnosis of amicrobial pustulosis of the folds was given. While there is no standard treatment, our patient's symptoms resolved following an oral prednisone taper and have not recurred since starting colchicine. The presence of pustules and erosive plaques in skin folds in young women with autoimmune conditions should raise suspicion for APF. The combination of localized neutrophilic spongiosis with intraepidermal or subcorneal pustules in conjunction with dermal changes of a neutrophilic dermatosis is a helpful clue to the diagnosis. If the patient does not already have a diagnosis of an underlying autoimmune condition, a presentation of APF should prompt further screening consisting of a relevant review of symptoms and appropriate assessment for autoimmune antibodies, since APF may precede the diagnosis of autoimmune disorders.

Clinical and histopathological aspects of the most common inflammatory non-infectious skin diseases.

The authors present a didactic overview of the most common inflammatory non-infectious skin diseases. This overview is not exhaustive, but illustrative, especially when regarding the aspect of a systematic approach to the evaluation of skin biopsy with an initial evaluation of the morphological pattern of the inflammatory process. This will subsequently facilitate the diagnosis. Photodocumentation of typical primary skin manifestations is attached to the photomicrograph images. This enables the pathologist to make a basic clinical-pathological correlation, which is of fundamental importance in dermatopathology.

Dermatitis Artefacta: A Practical Guide for Diagnosis and Management.

Dermatitis artefacta (DA) is a psycho-dermatologic condition based on patients' behavioral patterns, characterized by an intentional production of cutaneous lesions on their own skin. The clinical presentation can be highly variable. Patients with DA seldom seek psychological support or psychiatric consultation. More often, they seek help from their primary care physician or dermatologist. This review article aims to provide a practical guide for the diagnosis and management of AD and affected patients. A broad literature search was performed using the PubMed and Google Scholar electronic online databases, using key words "dermatitis artefacta", "diagnosis", "management", and "psychodermatology". The search was limited to English and Spanish language articles and was supplemented with themed books and book chapters. DA can occur in a variety of clinical presentations, and physicians should suspect DA in patients with a history of psychiatric disorders or extensive use of healthcare services. The ultimate goal of DA treatment may be a proper referral to mental health services. However, the prognosis is poor even when successful mental health referrals are achieved, with low recovery rates. A useful approach may include the suggestion that a mental health provider can help with the anxiety and the distress generated by the lesions: in this case in this case it will be crucial to discuss this with the mental health provider after obtaining informed consent from the patient. Considering the difficulty in promoting patients' adherence to treatment, the ideal setting for DA treatment is a psycho-dermatologic clinic, where both dermatologic and psychological interventions can be seamlessly integrated.

Pattern analysis for the diagnosis of inflammatory skin lesions in domestic animals: An overview.

Pattern analysis of inflammatory skin diseases is a technique that offers a systematic approach to the histologic diagnosis of skin diseases. First introduced to human dermatopathology in the 1970s, it was widely adopted by veterinary pathologists for the histologic diagnosis of skin diseases in animals. As the inflammatory pattern reflects, to varying extents, aspects of the underlying disease pathogenesis, its use has contributed to the recognition of novel skin diseases in domestic animals, particularly in dogs and cats. Alternative diagnostic approaches used in human dermatopathology, such as "tissue-reaction pattern" and a purely "anatomic approach" have not been as widely used in veterinary pathology. However, veterinary pathologists often combine pattern analysis with anatomic and etiologic factors. This overview outlines the technique, introduces the patterns, and discusses advantages and limitations of pattern analysis in veterinary diagnostic dermatopathology. While molecular analytic techniques and image informatics will undoubtedly prove to be revolutionary in many areas of diagnostic pathology, it is recognized in both human and veterinary arenas that the light microscopic interpretation of hematoxylin and eosin-stained tissue sections will remain the mainstay of routine dermatopathology diagnosis for the foreseeable future.