Alexander A Navarini

University of Zurich | UZH · Dermatologische Klinik und Poliklinik

Background Psoriatic arthritis (PsA) is a prevalent comorbidity among patients with psoriasis, heavily contributing to their burden of disease, usually diagnosed several years after the diagnosis of psoriasis. Objectives To investigate the predictability of psoriatic arthritis in patients with psoriasis and to identify important predictors. Metho...

Microphthalmia-associated transcription factor (MITF) plays pivotal roles in melanocyte development, function, and melanoma pathogenesis. MITF amplification occurs in melanoma and has been associated with resistance to targeted therapies. Here, we show that MITF regulates a global antioxidant program that increases survival of melanoma cell lines b...

Objectives The study aimed to improve the safety and accuracy of laser osteotomy (bone surgery) by integrating optical feedback systems with an Er:YAG laser. Optical feedback consists of a real‐time visual feedback system that monitors and controls the depth of laser‐induced cuts and a tissue sensor differentiating tissue types based on their chemi...

Zusammenfassung Die Dermatologische Klinik des Universitätsspitals Basel vereint die Disziplinen Dermatologie, Venerologie und Allergologie inkl. klinischer Immunologie. Sie zeichnet sich durch Patientenversorgung, Forschung und Weiterbildung auf universitärem Niveau aus. Mit ihrer 109-jährigen Geschichte bietet die Klinik ein breites Spektrum an e...

Feedback systems have been utilized to reduce the possible thermal side effects of lasers for surgery by means of temperature monitoring to control irrigation systems. In this study, we investigated the potential application of optical coherence tomography as a means of detecting bone dehydration status. We investigated the penetration depth of the...

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease which lacks efficacious standard-of-care treatments. Molecular studies of skin lesions revealed that IL-1β is central to the pathogenesis of PRP. Treatment of three patients with the IL-1-targeting biologics anakinra and canakinumab resulted in rapid clinical improvement and reversa...

This paper presents a new robust loss function, the T-Loss, for medical image segmentation. The proposed loss is based on the negative log-likelihood of the Student-t distribution and can effectively handle outliers in the data by controlling its sensitivity with a single parameter. This parameter is updated during the backpropagation process, elim...

Background: As the use of smartphones continues to surge globally, mobile applications (apps) have become a powerful tool for healthcare engagement. Prominent among these are dermatology apps powered by Artificial Intelligence (AI), which provide immediate diagnostic guidance and educational resources for skin diseases, including skin cancer. Obj...

Benchmark datasets for digital dermatology unwittingly contain inaccuracies that reduce trust in model performance estimates. We propose a resource-efficient data cleaning protocol to identify issues that escaped previous curation. The protocol leverages an existing algorithmic cleaning strategy and is followed by a confirmation process terminated...

Purpose Inflammatory bowel disease (IBD) occurring following allogenic stem cell transplantation (aSCT) is a very rare condition. The underlying pathogenesis is poorly defined. There is currently no systematic effort to exclude loss- or gain-of-function mutations in immune-related genes in stemcell donors. Methods Whole exome sequencing of hematop...

Background Teledermatology is currently finding its place in modern health care worldwide as a rapidly evolving field. Objective The aim of this study was to investigate the acceptance of teledermatology compared to in-person consultation from the perspective of patients and professionals. Methods This multicenter, cross-sectional pilot study was p...

Mutations in CD46 predispose to atypical hemolytic uremic syndrome (aHUS) with low penetrance. Factors driving immune-dysregulatory disease in individual mutation carriers have remained ill-understood. In addition to its role as a negative regulator of the complement system, CD46 modifies T cell-intrinsic metabolic adaptation and cytokine productio...

This paper presents a new robust loss function, the T-Loss, for medical image segmentation. The proposed loss is based on the negative log-likelihood of the Student-t distribution and can effectively handle outliers in the data by controlling its sensitivity with a single parameter. This parameter is updated during the backpropagation process, elim...

Background: Convolutional neural networks (CNNs) have outperformed dermatologists in classifying pigmented skin lesions under artificial conditions. We investigated, for the first time, the performance of three-dimensional (3D) and two-dimensional (2D) CNNs and dermatologists in the early detection of melanoma in a real-world setting. Methods: I...

Most commonly used benchmark datasets for computer vision contain irrelevant images, near duplicates, and label errors. Consequently, model performance on these benchmarks may not be an accurate estimate of generalization ability. This is a particularly acute concern in computer vision for medicine where datasets are typically small, stakes are hig...

Acute generalized exanthematous pustulosis (AGEP) is a rare, acute, severe cutaneous adverse reaction mainly attributed to drugs, although other triggers, including infections, vaccinations, ingestion of various substances, and spider bites, have also been described. AGEP is characterized by the development of edema and erythema followed by the eru...

The translatability of research is highly dependent on models that recapitulate human tissues and organs. Here, we describe a procedure for the generation of human epidermis organotypic cultures (HEOCs) from primary keratinocytes isolated from foreskin and adult skin as well as from an immortalized keratinocyte cell line (KerTr). We tested several...

Pruritus is a common symptom of cutaneous graft-versus-host disease (GVHD) following haematopoietic stem cell transplantation (HSCT). However, little is known about its prevalence, pathophysiology, perceptual characteristics, impact on quality of life and response to antipruritic therapies. The aim of this review was to determine the current knowle...

Background: Biallelic mutations in LIG4 encoding DNA-ligase 4 cause a rare immunodeficiency syndrome manifesting as infant-onset life-threatening and/or opportunistic infections, skeletal malformations, radiosensitivity and neoplasia. LIG4 is pivotal during DNA repair and during V(D)J recombination as it performs the final DNA-break sealing step....

Hand eczema (HE) is one of the most frequent dermatoses, known to be both relapsing and remitting. Regular and precise evaluation of the disease severity is key for treatment management. Current scoring systems such as the hand eczema severity index (HECSI) suffer from intra‐ and inter‐observer variance. We propose an automated system based on deep...

The development of high-frequency devices and transducers in recent years has enabled the growth of the use of dermatologic ultrasound. Real-time monitoring of the anatomy of the face during the application of aesthetic injectables potentially prevents complications such as vascular occlusions. Injecting physicians starting out in the practice of u...

BACKGROUND Teledermatology is currently finding its place in modern healthcare worldwide. OBJECTIVE The aim of this study was to investigate the acceptance of teledermatology compared to in-person consultation from the perspective of patients and professionals. METHODS This multicenter, cross-sectional pilot study was performed at secondary and t...

Background: The exact location of skin lesions is key in clinical dermatology. On one hand, it supports differential diagnosis (DD) since most skin conditions have specific predilection sites. On the other hand, location matters for dermatosurgical interventions. In practice, lesion evaluation is not well standardized and anatomical descriptions va...

A 4-year-old boy presented with blistering on his face and distal upper and lower extremities. Subepidermal blisters containing neutrophils and eosinophils visualized on histology supported the diagnosis of linear IgA bullous dermatosis of childhood (LABDC). The dermatosis presents with vesicles and tense blisters in an annular distribution, erythe...

Introduction Generalized pustular psoriasis (GPP) is a rare, severe, clinically heterogeneous disease characterized by flares of widespread, non-infectious, macroscopically visible pustules that occur with or without systemic inflammation, and are associated with significant morbidity and mortality. Historically, GPP has been classified as a varian...

Basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer in Switzerland and worldwide. Most BCCs can be treated in a curative setting. However, patients can develop locally destructive and, rarely, metastatic tumors that require a different treatment approach. The clinical subtype of individual lesions provides prognostic information a...

Psoriasis is a chronic inflammatory skin disease that often recurs at the same locations, indicating potential epigenetic changes of lesional skin cells. In this study, we discovered that fibroblasts isolated from psoriatic skin lesions retain an abnormal phenotype even after several passages in culture. Transcriptomic profiling revealed upregulati...

Generalized pustular psoriasis (GPP) is a rare, severe, potentially life-threatening, autoinflammatory, neutrophilic skin disease that may be accompanied by fever and leukocytosis. This paper describes the current state of knowledge on GPP in terms of classification, (differential) diagnosis and prevalence. We present a comparison of the genetics a...

What is this study about? Spesolimab is a drug developed to treat worsening disease (known as flares) of generalized pustular psoriasis (shortened to GPP). GPP is a rare disease in which pus-filled blisters or pustules suddenly form all over the body. Before a drug can be approved to treat the symptoms of a disease, clinical studies are performed t...

Zusammenfassung Die generalisierte pustulöse Psoriasis (GPP) ist eine seltene, schwere, potenziell lebensbedrohliche, autoinflammatorische, neutrophile Hauterkrankung, die von Fieber und Leukozytose begleitet sein kann. Diese Arbeit beschreibt den aktuellen Wissensstand zur GPP bezüglich Klassifizierung, (Differential‐)Diagnostik und Prävalenz. Wir...

This 16 page document: "Supplementary Material" contains additional methods and results.

Background: Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is an aggressive lymphoma variant. Anthracycline-based chemotherapy with rituximab is recommended as first-line treatment. Radiotherapy (RT) has been considered as a therapeutic option for local disease control in patients with solitary or localized lesions. Metho...

Background Leprosy is an infectious disease that mostly affects underserved populations. Although it has been largely eliminated, still about 200’000 new patients are diagnosed annually. In the absence of a diagnostic test, clinical diagnosis is often delayed, potentially leading to irreversible neurological damage and its resulting stigma, as well...

Background: Inconsistent data exist regarding the influence of parasitic infection on the prevalence of allergic sensitization and disorders. Objective: To investigate the impact of geohelminth and protozoan infections on sensitization patterns and allergic symptoms of children living in low-income communities in Gqeberha, South Africa. Methods...

Generalized pustular psoriasis (GPP) is a rare, potentially life-threatening disease characterized by episodes of widespread sterile macroscopic pustules, with or without systemic inflammation and/or plaque psoriasis. Multiple GPP subtypes have been described, from acute GPP of von Zumbusch to milder, annular pustular psoriasis. Generalized pustula...

Generalized pustular psoriasis (GPP) is a rare neutrophilic skin condition characterized by episodes of widespread eruption of sterile macroscopic pustules that can be associated with systemic inflammation. The rarity of GPP and its heterogeneous cutaneous and extracutaneous symptoms pose considerable challenges to the development and adoption of c...

Background Generalized pustular psoriasis (GPP) is a rare, life-threatening, inflammatory skin disease characterized by widespread eruption of sterile pustules. Interleukin-36 signaling is involved in the pathogenesis of this disorder. Spesolimab, a humanized anti–interleukin-36 receptor monoclonal antibody, is being studied for the treatment of GP...

Background Multiple studies have compared the performance of artificial intelligence (AI)–based models for automated skin cancer classification to human experts, thus setting the cornerstone for a successful translation of AI-based tools into clinicopathological practice. Objective The objective of the study was to systematically analyse the curre...

Insufficient sleep duration or quality are associated with various adverse health outcomes. Whereas sleep disorders were studied in a few skin conditions, data in a more comprehensive dermatology population are lacking. We sought to describe the prevalence, causes and consequences of sleep disorders in dermatology patients. In this cross-sectional,...

Ultraviolet (UV) light and incompletely understood genetic and epigenetic variations determine skin color. Here we describe an UV- and microphthalmia-associated transcription factor (MITF)-independent mechanism of skin pigmentation. Targeting the mitochondrial redox-regulating enzyme nicotinamide nucleotide transhydrogenase (NNT) resulted in cellul...

Hidradenitis suppurativa/acne inversa is a scarring disease of the intertrigines that is now intensively researched. Improved pathogenetic understanding has led to the introduction of tumor necrosis factor alpha (TNF‑α) inhibition, which represents a major advance over traditional broad immunosuppression and antibiotic administration. In addition,...

Background In a previous proof-of-concept study we have demonstrated that visual exposure to specific colors results in pruritic or antipruritic effects. Objectives To determine the effect of “antipruritic” colors when using immersive virtual reality (VR) and to assess whether psychometric values correlate with the response to the color exposure....

Background Phototherapy has been a mainstay therapy for dermatological diseases since more than a century. Although phototherapy is still extensively used and some recommendations exist, only scarce data are available addressing disease‐specific differences in cumulative doses, treatment durations and costs. Knowledge of such differences could help...

Background: The use of digital health resources is growing quickly as they are easily accessible and permit self-evaluation. Yet, research on consumer health informatics platforms is insufficient. Chatbots, interactive conversational platforms based on artificial intelligence, can facilitate access to specific information. Hidradenitis suppurativa...

Physicians’ and patients’ perspectives can vary significantly. For a long time, physicians considered psoriasis a non-pruritic dermatosis until a survey found pruritus to be the most bothersome symptom among psoriasis patients. In our study, we wanted to get an insight into the factors that affect patients and evaluate whether gender differences ex...

Cutaneous leishmaniasis (CL) is caused by protozoa of the genus Leishmania and typically manifests as multiple or single ulcers or papulo‐nodular lesions. Atypical lesions are rare but can simulate a large variety of dermatological disorders.¹ A 65‐year‐old traveler returning from Spain and Portugal presented in January 2020 to our department with...

Introduction Generalized pustular psoriasis (GPP) is a rare, potentially life-threatening disease characterised by recurrent flares of widespread neutrophilic aseptic skin pustular eruption. Despite the availability of approved biologics for GPP in Japan, Taiwan and Thailand, associated evidence is largely based on uncontrolled studies in which acu...

Topical treatment is crucial for the successful management of plaque psoriasis. Topicals are used either as a stand-alone therapy for mild psoriasis or else in combination with UV or systemic treatment for moderate-to-severe disease. For the choice of a suitable topical treatment, the formulation matters and not just the active substances. This exp...

BackgroundANCA-associated vasculitis (AAV) and Sjögren’s syndrome (SS) are uncommon autoimmune diseases. The co-occurrence in the same patient has been rarely described. Acromegaly has been associated with autoimmune thyroiditis, but the prevalence of other autoimmune disorders such as AAV and SS has not been evaluated in acromegaly.Methods Charact...

Abstract Introduction Facial moisturizers are commonly used by healthy women and increasingly men of all age groups. This study aimed to investigate the effects of moisturizer discontinuation and the subsequent evolution of symptoms. Methods Two prospective observational split-face comparison pilot studies were performed in Switzerland and enrolled...

(Audio‐)visual itch transmission is referred to as “contagious itch” (CI) and has been linked to an evolutionarily ingrained ectoparasite defense system. Disgust is considered to be part of the behavioral immune system aimed to prevent the spreading of pathogens. Although they probably serve a similar purpose, the relationship between CI and disgus...

Imiquimod 5% is approved for topical treatment of actinic keratosis (AKs), superficial basal cell carcinoma and condylomata acuminata, the 3.75% formulation for the treatment of AKs and genital warts. Imiquimod has also been used off-label in various other skin conditions (eg, Bowen's disease, lentigo maligna, vulvar intraepithelial neoplasia) incl...

The use of dermal fillers has increased manifold over the past decade, which has been attributed to the ever-increasing need of the population for being young. Fillers have become quite popular both among patients and treating physicians due to their quick and quite predictable results. Filler injection is a safe procedure in the hands of an experi...

Importance: Although palmoplantar pustulosis (PPP) can significantly impact quality of life, the factors underlying disease severity have not been studied. Objective: To examine the factors associated with PPP severity. Design, setting, and participants: An observational, cross-sectional study of 2 cohorts was conducted. A UK data set includin...

Background: The COVID 19 pandemic increased publication productivity enormously with numerous new COVID-19-related articles appearing daily, despite the fact that many health care workers in the partially overburdened national health care systems were faced with major challenges. Methods: In a cross-sectional, observational, retrospective study we...

Background The traditional patient‐physician relationship is being changed by the patients' searches for medical information on the Internet and in social media (SM). Freely available medical information online bears enormous potential but also holds dangers. Methods In this cross‐sectional, questionnaire‐based study, the patients' motivation, pre...

The use of dermal fillers has increased manifold over the past decade, which has been attributed to the ever-increasing need of the population for being young. Fillers have become quite popular both among patients and treating physicians due to their quick and quite predictable results. Filler injection is a safe procedure in the hands of an experi...

Zusammenfassung Telemedizin findet seit Jahrzehnten Anwendung im Alltag von Dermatologen. Insbesondere in afrikanischen Ländern mit begrenzter medizinischer Versorgung, zu überbrückenden geografischen Distanzen und einem zwischenzeitlich relativ gut ausgebauten Telekommunikationssektor liegen die Vorteile auf der Hand. Nationale und internationale...