Linear IgA bullous dermatosis of childhood: Retrospective single-center cohort.

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disorder impacting children and adults. In this single-center retrospective chart review of pediatric patients with LABD at a large tertiary referral center, we report the unifying and unique clinical features of 10 pediatric patients. Patients typically presented with the "cluster of jewels" sign (n = 6; 60%), mucous membrane involvement (n = 5; 50%) and had a mean disease duration of 38 months; six patients (60%) required inpatient admission for management of their skin disease, including all five patients who had mucous membrane involvement. Our findings suggest that pediatric LABD may be a disease with high morbidity and may be associated with severe complications when mucous membranes are involved.

Differential proteomic expression in indolent versus transforming oral lichen planus.

Oral lichen planus (OLP) confers an approximately 1% risk of transformation to oral squamous cell carcinoma (OSCC). Early identification of high-risk OLP would be very helpful for optimal patient management. We aimed to discover specific tissue-based protein biomarkers in patients with OLP who developed OSCC compared to those who did not. We used laser capture microdissection- and nanoLC-tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens in patients with indolent OLP (no OSCC after at least 5-year follow-up, n = 6), transforming OLP (non-dysplastic epithelium with lichenoid inflammation marginal to OSCC, n = 6) or normal oral mucosa (NOM, n = 5). Transforming OLP protein profile was enriched for actin cytoskeleton, mitochondrial dysfunction and oxidative phosphorylation pathways. CA1, TNNT3, SYNM and MB were overexpressed, and FBLN1 was underexpressed in transforming OLP compared with indolent OLP. Integrin signalling and antigen presentation pathways were enriched in both indolent and transforming OLP compared with NOM. This proteomic study provides potential biomarkers, such as CA1 overexpression, for higher-risk OLP. While further validation studies are needed, we propose that epithelial-mesenchymal transition may be involved in OLP carcinogenesis.

Differential proteomic expression profiles in vulvar lichen planus as compared to normal vulvar tissue, vulvar lichen sclerosus, or oral lichen planus: An exploratory study.

Vulvar lichen planus (VLP) is a chronic inflammatory disease which adversely affects patients' quality of life. The pathogenesis of VLP is unknown although Th1 immune response has been implicated. We aimed to discover specific tissue-based protein biomarkers in VLP compared to normal vulvar tissue (NVT), vulvar lichen sclerosus (VLS) and oral lichen planus (OLP). We used laser capture microdissection-liquid chromatography- tandem mass spectrometry to assess protein expression in fixed lesional mucosal specimens from patients with VLP (n = 5). We then compared proteomic profiles against those of NVT (n = 4), VLS (n = 5), OLP (n = 6) and normal oral mucosa (n = 5), previously published by our group. IL16, PTPRC, PTPRCAP, TAP1 and ITGB2 and were significantly overexpressed in VLP compared to NVT. Ingenuity pathway analysis identified antigen presentation and integrin signalling pathways. Proteins overexpressed in both VLP versus NVT and OLP versus NOM included IL16, PTPRC, PTPRCAP, TAP1, HLA-DPB1, HLA-B and HLA-DRA. This proteomic analysis revealed several overexpressed proteins in VLP that relate to Th1 autoimmunity, including IL16. Overlapping pathways, including those involving IFNγ and Th1 signalling, were observed between VLP, VLS, and OLP.

Development and multicenter international validation of a diagnostic tool to differentiate between pemphigoid gestationis and polymorphic eruption of pregnancy.

BACKGROUND: Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) may be similar morphologically but confer different maternal and fetal risks. Direct immunofluorescence is the gold standard test used to differentiate between the 2 diagnoses but is not always available. OBJECTIVE: To develop and validate a clinical scoring system to differentiate PG from PEP. METHODS: After developing a scoring system based on differentiating clinical factors reported in existing literature, we tested its diagnostic accuracy in a retrospective international multicenter validation study in collaboration with the European Academy of Dermatology and Venereology's Skin Diseases in Pregnancy Taskforce. RESULTS: Nineteen pregnancies (16 patients) affected by PG and 39 pregnancies (39 patients) affected by PEP met inclusion criteria. PG had a mean score of 4.6 (SD, 2.5) and PEP had a mean score of -0.3 (SD, 2.0). The area under the curve was 0.93 (95% CI, 0.86-1.00). Univariate analysis revealed that almost all criteria used in the scoring system were significantly different between the groups (P < .05), except for skip pregnancy and multiple gestations, which were then removed from the final scoring system. LIMITATIONS: Small retrospective study. CONCLUSION: The Pregnancy Dermatoses Clinical Scoring System may be useful to differentiate PG from PEP in resource-limited settings.

Histopathological features of pemphigoid gestationis and polymorphic eruption of pregnancy: A blinded retrospective comparative study of 31 cases.

BACKGROUND: Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) are pregnancy-related dermatoses. Definitive diagnosis often relies upon histopathology and direct immunofluorescence (DIF). PG is associated with fetal and neonatal risks, while PEP confers minimal risk. OBJECTIVE: We aimed to compare histopathologic features to determine key differentiators. METHODS: A retrospective cohort study of PG and PEP cases, with accompanying DIF, conducted from 1995 to 2020. Skin biopsies were examined independently in a blinded fashion by two dermatopathologists for a list of histopathological features. RESULTS: Twenty-one cases of PG and 10 cases of PEP were identified. PG had significantly denser eosinophils than PEP (mean 155 vs. 48 cells/5 hpf; p < 0.018). PG was also noted to have eosinophilic spongiosis and eosinophils at the dermal-epidermal junction more frequently compared to PEP (80% PG vs. 10% PEP; p < 0.001). A mean cutoff value of 86 eosinophils and a mean optimal sensitivity and specificity of 81% and 83%, respectively, for eosinophils density's diagnostic power of PEP versus PG were achieved. Subepithelial separation was exclusively seen in PG (40% vs. 0%; p < 0.007). CONCLUSION: Eosinophilic spongiosis, eosinophilic epitheliotropism, and dense superficial dermal eosinophils were diagnostic of PG. Given overlapping clinicopathologic features, however, DIF results with clinicopathologic correlation, remain the gold standard.

Histopathologic features predictive of perivascular deposition of IgA on direct immunofluorescence in cases of leukocytoclastic vasculitis: A retrospective study of 112 specimens.

IgA vasculitis is a small-vessel vasculitis subtype with increased risk of systemic involvement. We aimed to investigate if any light-microscopic features can predict the presence of perivascular granular IgA deposits on direct immunofluorescence (DIF) microscopy. We performed a retrospective search of cutaneous pathology reports from our internal and consultation practice (January 1, 2010-October 5, 2021) with a diagnosis of leukocytoclastic vasculitis and accompanying DIF. A blinded dermatopathologist reviewed standard microscopy slides for predetermined histopathological features. Fifty-six biopsies (48 patients) and 56 biopsies (42 patients) met inclusion criteria for IgA+ and IgA-, respectively. The presence of eosinophils and mid and deep dermal inflammation were statistically more associated with IgA- (41/56 [73.2%] and 31/56 [55.4%], respectively) than IgA+ cases (28/56 [50.0%] and 14/56 [25.0%]; p = 0.049 and 0.006, respectively, chi-squared test). Other microscopic criteria recorded were not significantly different between the two groups (p > 0.05, chi-squared and Fisher's exact tests). In this retrospective study of 112 cases, we found that while the absence of eosinophils and absence of mid- and deep inflammation were correlated with increased likelihood of IgA perivascular deposition on DIF, no other histopathological features on light microscopy tested could reliably predict the presence of IgA perivascular deposition on DIF. Therefore, DIF remains a necessary component for the accurate diagnosis of cutaneous IgA vasculitis.

Pediatric lichen planus: A single-center retrospective review of 26 patients with follow up.

BACKGROUND/OBJECTIVES: Pediatric lichen planus (LP) is rare with variable prevalence and atypical presentations compared to adults. Data on LP are lacking for the pediatric population in the United States. We present demographics, presentations, and treatments for a pediatric LP cohort. METHODS: We reviewed 26 patients diagnosed with LP at 20 years or younger. Treatment responses were defined as no response, partial response, and complete response. RESULTS: Demographics included 54% females and median diagnosis age of 16 years (range 6-20). Most patients presented with cutaneous LP (65%), with fewer having associated oral (23%), nail (7.7%), or genital (3.8%) involvement. Some had cutaneous-only LP (38%) or strictly mucosal LP (oral-only 19% and genital-only 15%). LP lesions were pruritic (50%), painful (19%), and/or asymptomatic (35%). Complete/partial responses occurred with medium-potency topical corticosteroids in cutaneous (n = 7; 64%), oral (n = 3; 75%), and genital LP (n = 3; 100%), with high/ultra-high potency topical corticosteroids in oral LP (n = 6; 86%), and with topical calcineurin inhibitors in genital LP (n = 2; 100%). Side effects were clobetasol-related oral candidiasis and biopsy-related penile depressed scar. Most patients with available follow-up achieved remission (n = 17; 81%). CONCLUSIONS: Pediatric LP usually presents in adolescence with cutaneous involvement and is symptomatic. However, patients frequently can have oral, genital, or nail lesions or may be asymptomatic, so they need thorough examinations and follow-up. Long-term remission is common due to treatment or natural disease course. Medium-potency corticosteroids are recommended for cutaneous, oral, and genital LP. Various other local and systemic therapies exist with successful treatment responses.

Differential proteomic expression in indolent vulvar lichen sclerosus, transforming vulvar lichen sclerosus and normal vulvar tissue.

Vulvar lichen sclerosus (VLS) confers approximately 3% risk of malignant transformation to vulvar squamous cell carcinoma (VSCC). We used unbiased proteomic methods to identify differentially expressed proteins in tissue of patients with VLS who developed VSCC compared to those who did not. We used laser capture microdissection- and nanoLC-tandem mass spectrometry to assess protein expression in individuals in normal vulvar tissue (NVT, n = 4), indolent VLS (no VSCC after at least 5 years follow-up, n = 5) or transforming VSCC (preceding VSCC, n = 5). Interferon-γ and antigen-presenting pathways are overexpressed in indolent and transforming VLS compared to NVT. There was differential expression of malignancy-related proteins in transforming VLS compared to indolent VLS (CAV1 overexpression, AKAP12 underexpression), particularly in the EIF2 translation pathway, which has been previously implicated in carcinogenesis. Results of this study provide additional molecular evidence supporting the concept that VLS is a risk factor for VSCC and highlights possible future biomarkers and/or therapeutic targets.

Updates and Proposed Diagnostic Approach to Psoriasiform Dermatoses.

Psoriasiform dermatoses represent a wide array of skin diseases commonly encountered by clinicians and pathologists. While they may present a diagnostic challenge, thorough observation coupled with proper interpretation of subtle additional clinical or histopathologic features provide clues to the correct diagnosis. In this review, we provide updates on emerging entities and develop a systemic approach to establish the pathologic diagnosis, with emphasis on the importance of clinicopathologic correlation.

Deep learning for dermatologists: Part II. Current applications.

Because of a convergence of the availability of large data sets, graphics-specific computer hardware, and important theoretical advancements, artificial intelligence has recently contributed to dramatic progress in medicine. One type of artificial intelligence known as deep learning has been particularly impactful for medical image analysis. Deep learning applications have shown promising results in dermatology and other specialties, including radiology, cardiology, and ophthalmology. The modern clinician will benefit from an understanding of the basic features of deep learning to effectively use new applications and to better gauge their utility and limitations. In this second article of a 2-part series, we review the existing and emerging clinical applications of deep learning in dermatology and discuss future opportunities and limitations. Part 1 of this series offered an introduction to the basic concepts of deep learning to facilitate effective communication between clinicians and technical experts.

Deep learning for dermatologists: Part I. Fundamental concepts.

Artificial intelligence is generating substantial interest in the field of medicine. One form of artificial intelligence, deep learning, has led to rapid advances in automated image analysis. In 2017, an algorithm demonstrated the ability to diagnose certain skin cancers from clinical photographs with the accuracy of an expert dermatologist. Subsequently, deep learning has been applied to a range of dermatology applications. Although experts will never be replaced by artificial intelligence, it will certainly affect the specialty of dermatology. In this first article of a 2-part series, the basic concepts of deep learning will be reviewed with the goal of laying the groundwork for effective communication between clinicians and technical colleagues. In part 2 of the series, the clinical applications of deep learning in dermatology will be reviewed and limitations and opportunities will be considered.

Whole-exome sequencing of transforming oral lichen planus reveals mutations in DNA damage repair and apoptosis pathway genes.

BACKGROUND: Oral lichen planus confers a 1% risk of transformation to oral squamous cell carcinoma. While prior exome sequencing studies have identified multiple genetic mutations in oral squamous cell carcinoma, mutational analyses of lichen planus-derived OSCC are lacking. We sought to clarify genomic events associated with oral lichen planus transformation. METHODS: Using rigorous diagnostic criteria, we retrospectively identified patients with non-transforming oral lichen planus (i.e., known to be non-transforming with 5 years of clinical follow-up; n = 17), transforming oral lichen planus (tissue marginal to oral squamous cell carcinoma, n = 9), or oral squamous cell carcinoma arising in lichen planus (n = 17). Gene mutational profiles derived from whole-exome sequencing on fixed mucosal specimens were compared among the groups. RESULTS: The four most frequently mutated genes in transforming oral lichen planus and oral squamous cell carcinoma (TP53, CELSR1, CASP8, and KMT2D) identified 12/17 (71%) of oral squamous cell carcinomas and 5/9 (56%) of transforming oral lichen planus but were absent in non-transforming oral lichen planus. We identified other known oral squamous cell carcinoma mutations (TRRAP, OBSCN, and LRP2) but also previously unreported mutations (TENM3 and ASH1L) in lichen planus-associated oral squamous cell carcinomas. CONCLUSIONS: These findings suggest alterations in DNA damage response and apoptosis pathways underlie lichen planus-related oral squamous cell carcinoma transformation and are supported by mutational signatures indicative of DNA damage. This study characterized patterns of mutational events present in oral lichen planus associated with squamous cell carcinoma and in squamous cell carcinoma associated with oral lichen planus but not in non-transforming oral lichen planus.

Utilization of skin biopsy for diagnosis in a case of Lafora disease.

Lafora disease is a rare inherited neurodegenerative disease with onset in adolescence. Patients present with progressive myoclonic seizures and cognitive decline. The disease is linked to mutations in either of the two genes encoding malin and laforin, and it is associated with the accumulation of polyglucosan inclusions (Lafora bodies [LBs]) in various tissues, such as brain, liver, muscle, and skin, with the skin being particularly accessible for biopsy. Histopathologic examination of affected tissue with demonstration of LBs, together with the presence of pathologic mutation in EPM2A or NHLRC1 genes, is sufficient for diagnosis of this neurologic disorder when clinically suspected. Here, we report the case of a 16-year-old female with progressive neurologic symptoms and homozygous mutation in the NHLRC1 gene encoding malin. The skin biopsy was instrumental in reaching the final diagnosis by showing LBs in sweat glands by histopathologic and electron microscopic examination.

Do histopathological features correlate with systemic manifestations in dermatomyositis? Analysis of 42 skin biopsy specimens from 22 patients.

BACKGROUND: Understanding whether specific histopathologic features on skin biopsy are predictive of systemic associations in dermatomyositis (DM) would be useful to guide clinical screening. METHODS: Through retrospective medical record search, clinical and laboratory findings of patients with DM were documented. Existing skin biopsy slides were re-reviewed blindly. RESULTS: Of all biopsy specimens (n = 42), the most frequent histopathological finding was vacuolar interface dermatitis (95%). Other features included perivascular lymphocytic infiltrate (71%), increased dermal mucin (40%), vessel wall thickening (12%), follicular plugging (9.5%), and dermal sclerosis (7%). Neutrophilic infiltrate was observed in three biopsies from a patient with adalimumab-associated DM. Vasculitis was not observed. There was no statistically significant difference in the presence of any histopathological feature and that of various systemic manifestations (i.e., myopathy, interstitial lung disease [ILD] and malignancy). However, we observed that dense lichenoid infiltrate rather than pauci-inflammatory changes correlated with severe itching (p < 0.001). Patients with MDA-5 antibodies were significantly more likely to have vasculopathy than those without (p = 0.029*). CONCLUSIONS: No dermatopathologic feature was reliably predictive of myopathy, ILD, or malignancy. This finding implies that, regardless of histopathologic findings, patients should be screened for associated conditions as clinically indicated.

Impact of adding an IgG4 conjugate to routine direct immunofluorescence testing for subepithelial and intraepithelial autoimmune blistering disorders.

BACKGROUND: Certain autoimmune bullous dermatoses are mediated by autoantibodies of the IgG4 subclass. We determined the diagnostic impact of adding IgG4 to our conventional direct immunofluorescence (DIF) panel. METHODS: For all cases submitted to our referral laboratory for DIF over 1 month (n = 630), we performed IgG4 testing and collected consecutive biopsy specimens showing definite or indeterminate linear or cell-surface deposition of IgG, IgG4, and/or C3. On retrospective blinded review, we classified the pattern and whether the findings were definite, indeterminate, or negative. When present, substantial background staining was recorded. RESULTS: Seventy DIF specimens met the inclusion criteria. Of 22 (31.4%) specimens equivocal for linear or cell-surface deposition, 9 (40.9%) had definitive IgG4 findings, either linear (3 of 14 equivocal linear cases; 21.4%) or cell-surface (6 of 8 equivocal cell-surface cases; 75.0%). Background deposition was substantial in 14 cases (20.0%) for IgG but in none for C3 or IgG4. CONCLUSION: IgG4 allowed the classification of over 40% of DIF cases that were otherwise equivocal by IgG and C3. IgG4 staining showed lower levels of non-specific background staining than IgG or C3. IgG4 appears to contribute most value in cases with cell-surface deposition or with equivocal linear IgG deposition and negative C3 results.

Subepithelial autoimmune bullous dermatoses disease activity assessment and therapy.

Subepidermal (subepithelial) autoimmune blistering dermatoses are a group of rare skin disorders characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The fourth article in this continuing medical education series presents the current validated disease activity scoring systems, serologic parameters, treatments, and clinical trials for bullous pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, bullous systemic lupus erythematosus, anti-p200 pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Subepithelial autoimmune blistering dermatoses: Clinical features and diagnosis.

Subepithelial autoimmune blistering dermatoses are a group of rare skin disorders that are characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The third article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major subepithelial autoimmune blistering dermatoses, including bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, mucous membrane pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Intraepithelial autoimmune blistering dermatoses: Clinical features and diagnosis.

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by the intraepithelial disruption of intercellular connections through the action of autoantibodies. The first article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major intraepithelial autoimmune blistering dermatoses, including pemphigus foliaceus, pemphigus erythematosus, pemphigus herpetiformis, fogo selvagem, pemphigus vulgaris, pemphigus vegetans, drug-induced pemphigus, IgA pemphigus, IgG/IgA pemphigus, and paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome.

Intraepithelial autoimmune bullous dermatoses disease activity assessment and therapy.

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by disruptions of inter-keratinocyte connections within the epidermis through the action of autoantibodies. The second article in this continuing medical education series presents validated disease activity scoring systems, serologic parameters of disease, treatments, and clinical trials for pemphigus and its subtypes.

Impact of clinical photographs on the accuracy and confidence in the histopathological diagnosis of mycosis fungoides.

BACKGROUND: The histopathological diagnosis of MF is challenging, and there is significant overlap with benign inflammatory processes. Clinical features may be relevant in the assessment of skin biopsies. METHODS: We provided photomicrographs to board-certified dermatopathologists and one hematopathologist with and without accompanying clinical photographs and assessed accuracy and confidence in diagnosing MF. RESULTS: We found that access to clinical photographs improved diagnostic accuracy in both MF and non-MF (distractors); the degree of improvement was significantly higher in the non-MF/distractor category. Across all categories, diagnostic confidence level was higher when clinical images were available. CONCLUSION: These findings suggest that clinical images are useful in making an accurate diagnosis of MF, and may be particularly helpful in ruling it out when an inflammatory disorder is clinically suspected.