Psoriasiform dermatitides: A brief review

Final clinical diagnosis in cases of histopathologic psoriasiform dermatitis: retrospective cross-sectional analysis of a Southeastern United States population, 2004-2017

BACKGROUND

Psoriasiform dermatitis can be defined both clinically and histologically, but is not a traditionally recognized clinical or histologic diagnosis.

OBJECTIVE

Analyze the final clinical diagnosis, demographics and clinical characteristics in patients with histologic psoriasiform dermatitis.

METHODS

Retrospective cross-sectional analysis of patients with histologic psoriasiform dermatitis 2004-2017.

RESULTS

Patients (N = 586) were most often female (53.4%) and race/ethnicity included White (61.3%), Black (29.5%), Asian (4.8%), Hispanic (0.7%); mean (SD) age was 52.0 (17.9) years. Median time from histologic psoriasiform dermatitis to final clinical diagnosis was 0.5 months and median duration of follow-up was 6.0 years. The most frequently involved body sites were legs (37.2%), trunk (35.8%) and arms (25.3%). Final clinical diagnoses most associated with histologic psoriasiform dermatitis were psoriasis (N = 191, 32.6%), dermatitis (N = 173, 29.5%), "no clinical diagnosis" (N = 59, 10.1%) and cutaneous T-cell lymphoma (CTCL) or parapsoriasis (N = 48, 8.2%).

LIMITATIONS

Retrospective study at one academic center.

CONCLUSION

The most frequent clinical diagnoses associated with histologic psoriasiform dermatitis were psoriasis in about one third of patients, dermatitis in just under one third of patients, "no clinical diagnosis" in approximately 10% and CTCL/parapsoriasis in just under 10%.

Immune Checkpoint Inhibitor-Associated Cutaneous Adverse Events: Mechanisms of Occurrence

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs' unique molecular action that is mainly mediated by the activation of cytotoxic CD4+/CD8+ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs.

Might Necrotic Keratinocytes Contribute to the Diagnosis and Pathogenesis of Psoriasis?

INTRODUCTION

Psoriasis is a chronic inflammatory skin disease that can pose challenges for histopathological diagnosis. Recent research has emphasized the importance of necrotic keratinocytes, meaning keratinocytes undergoing programmed cell death, for diagnosing psoriasis. It has also become increasingly evident that programmed cell death pathways play a significant role in psoriasis's pathogenesis, development, and progression, including via a recently identified programmed cell death mechanism called "PANoptosis."

OBJECTIVES

In our study, we aimed to investigate the significance of necrotic keratinocytes in both the diagnosis and pathogenesis of psoriasis.

METHODS

We analyzed the number of necrotic keratinocytes in 135 samples of psoriasis, 57 samples of psoriasiform spongiotic dermatitis, and 71 samples of normal skin. We additionally assessed the distribution of necrotic keratinocytes in the upper, middle, and lower thirds of the epidermis.

RESULTS

Our findings revealed a significant difference in the total number of necrotic keratinocytes and their distribution within epidermal regions between patients with psoriasis and both the psoriasiform spongiotic dermatitis and control groups (p < .001). In particular, necrotic keratinocytes were predominantly found in the upper epidermis (77.5%) in patients with psoriasis. We also observed a strong correlation between Psoriasis Area and Severity Index scores and the total count of necrotic keratinocytes in patients with psoriasis (r = .72).

CONCLUSIONS

Our results highlight the role of necrotic keratinocytes, resulting from programmed cell death, as important marker cells in both the diagnosis and pathogenesis of psoriasis.

Oral mucosa and cutaneous manifestations of psoriasis in an older patient: A case report

BACKGROUND

Psoriasis is a common cutaneous disease; however, information about psoriasis-related oral mucosal lesions is scarce in the literature.

CASE DESCRIPTION

We report a case of a 73-year-old male patient with cutaneous and oral palatal alterations. An incisional biopsy of these lesions revealed psoriasis.

CONCLUSION

The current case highlights the importance of a systematic examination of the oral cavity in psoriasis patients for the appropriate diagnosis and management on the control of these lesions.

STAT2/Caspase3 in the diagnosis and treatment of psoriasis

BACKGROUND

Psoriasis is a classic chronic recurrent inflammatory skin disease characterized by skin inflammation and abnormal biological behaviour of keratinocytes. Although Signal Transducer And Activator Of Transcription 2 (STAT2) was found to play an important role in the Janus kinase (JAK)-STAT signalling pathway and contribute to the pathogenesis of psoriasis, its exact role in psoriasis remains unclear.

METHODS

Using bioinformatics analysis, we identified the key pathways that significantly impacted psoriatic lesions. After identifying the critical molecule gene differentially expressed in multiple public databases using the Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis, clinical samples were collected to validate the gene's significance. Its functions and underlying mechanism were also investigated in vitro. Lastly, we evaluated the diagnostic and therapeutic power of the target gene using the receiver operating characteristic curve (ROC), and gene association was assessed using Spearman correlation.

RESULTS

A significant correlation was found between cysteine-aspartic acid protease3 (Caspase3) and STAT2, and functional enrichment analysis revealed that they were both significantly up-regulated in psoriatic skin lesions compared to non-lesional tissues. Functional analysis revealed that Caspase3 functioned downstream of STAT2 in psoriasis. Lastly, we found that Caspase3 and STAT2 could be potential biomarkers for diagnosing and treating psoriasis.

CONCLUSIONS

In summary, STAT2 overexpression contributes to psoriasis progression by regulating Capase3 phosphorylation to induce excessive apoptosis of keratinocytes. Meanwhile, STAT2 and Capase3 were identified as promising biomarkers for the diagnosis and treatment of psoriasis and could be used for individualized treatments.

Psoriasiform Dermatitis in a COVID-19 Patient

Psoriasis is a chronic inflammatory papulosquamous disorder which affects around 2% of the world's population. A peak exacerbation in psoriatic symptoms was noted during COVID-19 due to lack of access to dermatological care mixed with heightened emotional stress during the pandemic. This case report describes a 52-year-old admitted male patient who sustained a diffuse rash on multiple areas of his body a week prior to testing positive for COVID-19. We explore plausible causes for the occurrence of the rash, discuss our treatment plan, include relevant clinical pictures, and review published literature to examine conditions that present similarly to the rash seen in our patient. It is crucial for dermatologists to be able to discern various systemic manifestations associated with cutaneous lesions, such as the one seen in this patient, in order to make an accurate and prompt diagnosis. A better understanding of the association between COVID-19 infection and psoriasiform lesions is needed for improving the prognostic and therapeutic outcomes in patients.

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.

Histopathologic Characterization of Mogamulizumab-associated Rash

Rash is one of the most common adverse events observed with mogamulizumab, an anti-C-C chemokine receptor 4 monoclonal antibody approved for previously treated mycosis fungoides (MF) and Sezary syndrome (SS). Given the nonspecific clinical presentations of this rash, histopathologic distinction from MF/SS is critical for informing clinical management. We performed a comprehensive characterization of the histopathologic findings in mogamulizumab-associated rash (MAR) with the integration of high-throughput sequencing of T-cell receptor (TCR) genes. Fifty-two biopsy specimens from 19 patients were evaluated retrospectively. Three major histologic reaction patterns were identified: spongiotic/psoriasiform dermatitis (33/52), interface dermatitis (11/52), and granulomatous dermatitis (8/52). Almost half of the specimens (21/52) showed at least 2 of these reaction patterns concurrently. Dermal eosinophils were not a consistent feature, being present in only half (27/52) of specimens and prominent in only 3. Features mimicking MF/SS, including lymphocyte exocytosis, lamellar fibroplasia, and adnexal involvement, were commonly seen but tended to be focal and mild. In 38/43 specimens with available immunohistochemistry, intraepidermal lymphocytes demonstrated a CD4:CD8 ratio ≤1 : 1. Low background levels of the patient's previously identified MF/SS-associated TCR sequence(s) were demonstrated in 20/46 specimens analyzed by high-throughput sequencing of TCR. We conclude that MAR may demonstrate diverse histologic features. Findings that may distinguish MAR from MF/SS include the inverted or normalized CD4:CD8 ratio within intraepidermal lymphocytes and demonstration of absent or nondominant levels of disease-associated TCR sequences. Correlation with the clinical findings and immunohistochemical and molecular characterization of the patient's MF/SS before mogamulizumab, when possible, may facilitate recognition of MAR.

Clinicopathological Features of Seborrheic-Like Dermatitis in HIV-Infected Adults: A Single Institutional Descriptive Cross-Sectional Study

BACKGROUND

Atypical and severe clinical presentations of seborrheic-like dermatitis (SLD) are associated with HIV infection, correlating with advanced disease or low CD4 counts. Previous studies documented histological findings characteristic of seborrheic dermatitis in HIV-positive patients.

OBJECTIVE

To expand current knowledge of the clinicopathological characteristics of SLD in South African HIV-seropositive individuals.

METHODS

This prospective study included HIV-seropositive adult patients presenting with SLD to a dermatology clinic from March 2017 to April 2018. A dermatologist established the diagnosis of SLD and the severity of the disease. Detail about antiretroviral therapy (ART), the latest CD4 count, and the viral load was retrieved from the patients' clinical records. Histopathological assessment of the patients' skin biopsies was recorded using standardized data sheets and semiquantifiable grades.

RESULTS

This study included 13 women and 17 men. Fifty percent of patients showed severe or very severe SLD. Six (20.0%) patients presented with erythroderma. Statistical analysis did not show a significant correlation between severity of disease and CD4 count, viral load, or ART, respectively. This study confirmed that the presence of confluent parakeratosis, necrotic keratinocytes, plasma cells, neutrophils with leukocytoclasia, and leukoexocytosis are histopathological clues to SLD occurring in HIV-seropositive patients.

CONCLUSION

SLD in HIV patients may present with varying clinical severity, including erythroderma. The association between the prevalence and severity of SLD with CD4 count, viral load, and ART requires further studies with larger patient populations. The presence of specific histopathological features in a skin biopsy of SLD is a clue to the diagnosis of HIV.

Diagnostic Workup and Evaluation of Patients with Prurigo Nodularis

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized oftentimes by symmetrically distributed, severely pruritic nodules. Currently, the pathophysiology of PN remains to be fully elucidated, but emerging evidence suggests that neuroimmune alterations play principal roles in the pathogenesis of PN. There are several associated etiologic factors thought to be associated with PN, including dermatoses, systemic, infectious, psychiatric, and neurologic conditions. We conducted a systematic literature review to evaluate the clinical presentation, diagnosis, and etiologic factors of PN. In this review, we discuss common differential diagnoses of PN and recommend an evidence-based, standardized diagnostic evaluation for those with suspected PN.

Pityriasis Rubra Pilaris With Extensive Follicular Acantholysis Resembling Pemphigus Vulgaris: A Case Report

Pityriasis rubra pilaris (PRP) is a rare, chronic, heterogeneous, papulosquamous inflammatory dermatosis of unknown etiology. Although erythematous scaly patches characterize the classic presentation of PRP, a broad range of clinical presentations has been reported. Histologically, PRP is characterized by psoriasiform acanthosis with alternating orthokeratosis and parakeratosis and rarely small acantholytic foci. In this article, we report a patient who presented with diffuse erythroderma and extensive acantholysis mimicking pemphigus vulgaris histologically.

Elevated Gene Expression of Interleukin-32 Isoforms Alpha, Beta, Gamma, and Delta in the Peripheral Blood of Chronic Psoriatic Patients

Inflammatory-mediated reactions have been implicated as contributors in a number of dermatological disorders, including psoriasis. However, the potential of interleukin (IL)-32 and its isoforms to contribute to the pathogenesis of psoriasis remains unexplored. This study was undertaken to investigate the role of IL-32 and its isoforms IL-32α, IL-32β, IL-32γ, and IL-32δ in the peripheral blood of psoriatic patients. The majority of chronic plaque psoriatic patients showed elevated IL-32 mRNA levels in the peripheral blood mononuclear cells (PBMCs) as compared with the levels of IL-32 mRNA in PBMCs of healthy controls (p = 0.001). To further investigate the role of elevated levels of IL-32 in psoriatic patients, IL-32 isoforms mRNAs were determined. All tested isoforms IL-32α, IL-32β, IL-32γ, and IL-32δ were overexpressed in psoriatic patients PBMCs as compared with healthy controls’ PBMCs (p < 0.05). IL-32α mRNA expression was also significantly higher as compared with all other isoforms of IL-32 in PBMCs of psoriatic patients (p < 0.001). In short, this is the first study that shows the role of IL-32 and its isoforms in the peripheral blood of psoriatic patients. Our novel findings support an association between elevated levels of IL-32 and psoriasis. The data also suggest that a major proinflammatory response of IL-32 may derive from IL-32α isoform in psoriasis.