Deep Learning-Based Objective and Reproducible Osteosarcoma Chemotherapy Response Assessment and Outcome Prediction.

Osteosarcoma is the most common primary bone cancer, whose standard treatment includes pre-operative chemotherapy followed by resection. Chemotherapy response is used for prognosis and management of patients. Necrosis is routinely assessed after chemotherapy from histology slides on resection specimens, where necrosis ratio is defined as the ratio of necrotic tumor/overall tumor. Patients with necrosis ratio ≥90% are known to have a better outcome. Manual microscopic review of necrosis ratio from multiple glass slides is semiquantitative and can have intraobserver and interobserver variability. In this study, an objective and reproducible deep learning-based approach was proposed to estimate necrosis ratio with outcome prediction from scanned hematoxylin and eosin whole slide images (WSIs). To conduct the study, 103 osteosarcoma cases with 3134 WSIs were collected. Deep Multi-Magnification Network was trained to segment multiple tissue subtypes, including viable tumor and necrotic tumor at a pixel level and to calculate case-level necrosis ratio from multiple WSIs. Necrosis ratio estimated by the segmentation model highly correlates with necrosis ratio from pathology reports manually assessed by experts. Furthermore, patients were successfully stratified to predict overall survival with P = 2.4 × 10-6 and progression-free survival with P = 0.016. This study indicates that deep learning can support pathologists as an objective tool to analyze osteosarcoma from histology for assessing treatment response and predicting patient outcome.

Autism as a Disorder of Affective Empathy.

Since the first description by Leo Kanner, individuals with autism spectrum disorder (ASD) have been attributed a reduced empathy. However, it has not yet been clarified how empathy is specifically impaired in autism. Typically, scholars distinguish between the affective and the cognitive dimensions of empathy. The latter largely overlaps with the concept of the theory of mind (ToM), according to which we need internal inferences or simulations for gaining access to the hidden mental states of others. Since a deficit in ToM is a widely accepted explanation for difficulties of individuals with ASD in social interactions, limitations in cognitive empathy are accordingly assumed. Regarding affective empathy, there are contradictory results using various methods, showing an impaired affective empathy. The main aim of the paper is to present ASD primarily as a disorder of shared interpersonal and interaffective experiences and thus of affective empathy by means of a phenomenological analysis considering empirical studies. In this framework, a deficit of the ToM is accepted but criticized as a central explanatory approach for ASD since (1) it assumes a fundamental inaccessibility of other people, which does not correspond to our everyday social situations, and (2) it manifests developmentally long after the first signs of ASD, which means that its deficit cannot explain the basic autistic difficulties in social interactions.

Skin Tests versus Serology: Specific IgE May Suffice for Diagnosis of Vespid Venom Allergy and Follow-Up of Allergen Immunotherapy.

INTRODUCTION: In adults, allergic reactions to insect stings are among the most frequent causes of anaphylaxis, a potentially life-threatening condition. Recurrent anaphylaxis following vespid stings may be prevented by allergen immunotherapy (AIT). The aim of this study was to evaluate the benefit of measuring venom-induced wheal area in intracutaneous skin tests (ICT), in comparison to various serological and clinical parameters, for the diagnosis of severe vespid venom allergy and during follow-up of AIT. METHODS: We conducted a monocentric, retrospective evaluation of 170 patients undergoing AIT against vespid venoms. We scanned ICT wheals at baseline and at three time points after AIT initiation and measured wheal area using objective data analysis software. RESULTS: We found that ICT histamine-induced and venom-induced wheal areas did not correlate. In addition, the venom-induced wheal area was independent from the minimal venom concentration required to elicit a wheal in an ICT and all other parameters. No correlation was found between wheal area and the severity of anaphylaxis. Wheal area standardized to the application of 0.1 µg/mL venom inversely correlated with anaphylaxis severity and positively correlated with venom-specific IgE levels. During AIT, mean areas of venom-induced wheals did not change. In contrast, venom-specific IgG and IgG4 levels, and the minimal venom concentration required to induce a positive ICT result increased, while the venom wheal area standardized to 0.1 µg/mL venom application and specific IgE levels decreased over time. CONCLUSION: Wheal area evaluation did not provide additional information over specific IgE analysis. We therefore recommend that ICTs are used only as a secondary measure for confirming serological test results.

Joint electric and magnetic beam deflection experiments and quantum chemical studies of MSn12 clusters (M = Al, Ga, In): on the interplay of geometric structure and magnetic properties in nanoalloys.

MSn12 clusters (M = Al, Ga, In) were studied in electric and magnetic beam deflection experiments at temperatures of 16 K and 30 K. For all three species, the results of the electric beam deflection experiments indicate the presence of two structural isomers of which one is considerably polar. The magnetic beam deflection experiments show atom-like beam splitting (superatomic behavior) with g-factors of 2.6-2.7 for a fraction of the clusters in the molecular beam, indicating significant spin-orbit coupling. On the one hand, we investigate by several experiments combining electric and magnetic deflectors how the superatomic and polar fractions are linked proving the correlation of the Stark and Zeeman effects. On the other hand, the magnetic deflection behavior is examined more thoroughly by performing quantum chemical calculations. By systematic distortion of an artificial icosahedral tin cage towards the global minimum structure, which has a pyritohedral geometry, the shifts in the magnitude of the g-factor are found to be mainly caused by a single dominant electronic excitation. This allows one to develop a semi-quantitative understanding of the magnetic behavior. On the basis of avoided crossings in the rotational Zeeman diagram, simulations of the magnetic beam deflection comprising computed rotational constants, vibrational modes, g-factors and spin-rotation coupling constants are performed which resemble our experimental findings in satisfactory agreement. With this, a better understanding of the magnetic properties of nanoalloy clusters can be achieved. However, the geometric structures of the polar isomers are still unknown.

"What is this strange sensation?" A qualitative exploration of metaphors used to verbalise hard-to-describe experiences by people with epilepsy.

Mental health comorbidities are frequent in epilepsy. Consequently, psychotherapy is becoming increasingly important. To address the psychological needs of people with epilepsy (PwE) it is essential to understand the subjective experiences of seizures better. There is little research on how people report seizures, and which psychological representations they have. We conducted a thematic analysis based on 42 (micro-phenomenological) interviews with 15 participants on their experiences of seizures. In these interviews, we identified three categories of seizure descriptions: (1) phenomena related to the body and emotions; (2) the moments that are difficult to describe; and (3) the use of figurative language and metaphors. Paroxysmal physical and psychological sensations were often reported spontaneously by the participants. The moments that were difficult to describe were expressed, among other things, through the use of paradoxes or the report of a 'strange' feeling and led participants to use figurative language. As these metaphors can reveal important information about people's subjective experiences, they were analyzed in detail. We identified the three main types of metaphors that the participants used most frequently: (1) perception, (2) nature, and (3) battle. The theme of battle was most frequently used in different forms and was closely related to the metaphors from the fields of perception and nature, thus representing a key point in the personal experience of seizures. These findings can contribute to developing psychotherapeutic approaches for the treatment of seizure disorders.

Telestration with augmented reality improves surgical performance through gaze guidance.

BACKGROUND: In minimally invasive surgery (MIS), trainees need to learn how to interpret the operative field displayed on the laparoscopic screen. Experts currently guide trainees mainly verbally during laparoscopic procedures. A newly developed telestration system with augmented reality (iSurgeon) allows the instructor to display hand gestures in real-time on the laparoscopic screen in augmented reality to provide visual expert guidance (telestration). This study analysed the effect of telestration guided instructions on gaze behaviour during MIS training. METHODS: In a randomized-controlled crossover study, 40 MIS naive medical students performed 8 laparoscopic tasks with telestration or with verbal instructions only. Pupil Core eye-tracking glasses were used to capture the instructor's and trainees' gazes. Gaze behaviour measures for tasks 1-7 were gaze latency, gaze convergence and collaborative gaze convergence. Performance measures included the number of errors in tasks 1-7 and trainee's ratings in structured and standardized performance scores in task 8 (ex vivo porcine laparoscopic cholecystectomy). RESULTS: There was a significant improvement 1-7 on gaze latency [F(1,39) = 762.5, p < 0.01, ηp2 = 0.95], gaze convergence [F(1,39) = 482.8, p < 0.01, ηp2 = 0.93] and collaborative gaze convergence [F(1,39) = 408.4, p < 0.01, ηp2 = 0.91] upon instruction with iSurgeon. The number of errors was significantly lower in tasks 1-7 (0.18 ± 0.56 vs. 1.94 ± 1.80, p < 0.01) and the score ratings for laparoscopic cholecystectomy were significantly higher with telestration (global OSATS: 29 ± 2.5 vs. 25 ± 5.5, p < 0.01; task-specific OSATS: 60 ± 3 vs. 50 ± 6, p < 0.01). CONCLUSIONS: Telestration with augmented reality successfully improved surgical performance. The trainee's gaze behaviour was improved by reducing the time from instruction to fixation on targets and leading to a higher convergence of the instructor's and the trainee's gazes. Also, the convergence of trainee's gaze and target areas increased with telestration. This confirms augmented reality-based telestration works by means of gaze guidance in MIS and could be used to improve training outcomes.

Seizures as a Struggle between Life and Death: An Existential Approach to the Psychosocial Impact of Seizures in Candidates for Epilepsy Surgery.

INTRODUCTION: Mental health comorbidities such as depression and anxiety are common in epilepsy, especially among people with pharmacoresistant epilepsy who are candidates for epilepsy surgery. The Psychology Task Force of the International League Against Epilepsy advised that psychological interventions should be integrated into comprehensive epilepsy care. METHODS: To better understand the psychological impact of epilepsy and epileptic seizures in epilepsy surgery candidates, we analysed interviews with this subgroup of patients using Karl Jaspers' concept of limit situations, which are characterised by a confrontation with the limits and challenges of life. These are especially chance, randomness, and unpredictability, death and finitude of life, struggle and self-assertion, guilt, failure, and falling short of one's aspirations. RESULTS: In 43 interviews conducted with 15 people with drug-resistant epilepsy who were candidates for epilepsy surgery, we found that these themes are recurrent and have a large psychosocial impact, which can result in depression and anxiety. For some people, epileptic seizures appear to meet the criteria for traumatic events. CONCLUSION: Understanding epilepsy and seizures as existential challenges complements the neurobiological explanations for psychological comorbidities and can help tailor psychological interventions to the specific needs of people with epilepsy, especially those who are candidates for surgical treatment.

Antibiotic Stewardship and Therapeutic Drug Monitoring of ß-Lactam Antibiotics: Is There a Link? An Opinion Paper.

PURPOSE: In critically ill patients, changes in the pharmacokinetics (PK) of ß-lactams can lead to significant variations in serum concentrations, with possibly detrimental effects on outcomes. The utilization of individually calculated doses, extended infusion regimen, and therapeutic drug monitoring (TDM)-guided dose adjustments can mitigate the PK changes and help to achieve and attain an individual PK target. METHODS: We reviewed relevant literature from 2004 to 2021 using 4 search engines (PubMed, Web of Science, Scopus, and Google Scholar). Unpublished clinical data were also examined. RESULTS: TDM-guided, individualized dosing strategies facilitated PK target attainment and improved patient outcomes. TDM-guided therapy is a core concept of individualized dosing that increases PK target attainment and identifies possible toxic ß-lactam concentrations. CONCLUSIONS: Individualized dosing and TDM facilitate the rational use of ß-lactams and are integral for antibiotic stewardship interventions in critical care, affording the optimal exposure of both pathogen and drugs, along with enhanced treatment efficacy and reduced emergence of antimicrobial resistance.

Independent real-world application of a clinical-grade automated prostate cancer detection system.

Artificial intelligence (AI)-based systems applied to histopathology whole-slide images have the potential to improve patient care through mitigation of challenges posed by diagnostic variability, histopathology caseload, and shortage of pathologists. We sought to define the performance of an AI-based automated prostate cancer detection system, Paige Prostate, when applied to independent real-world data. The algorithm was employed to classify slides into two categories: benign (no further review needed) or suspicious (additional histologic and/or immunohistochemical analysis required). We assessed the sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) of a local pathologist, two central pathologists, and Paige Prostate in the diagnosis of 600 transrectal ultrasound-guided prostate needle core biopsy regions ('part-specimens') from 100 consecutive patients, and to ascertain the impact of Paige Prostate on diagnostic accuracy and efficiency. Paige Prostate displayed high sensitivity (0.99; CI 0.96-1.0), NPV (1.0; CI 0.98-1.0), and specificity (0.93; CI 0.90-0.96) at the part-specimen level. At the patient level, Paige Prostate displayed optimal sensitivity (1.0; CI 0.93-1.0) and NPV (1.0; CI 0.91-1.0) at a specificity of 0.78 (CI 0.64-0.89). The 27 part-specimens considered by Paige Prostate as suspicious, whose final diagnosis was benign, were found to comprise atrophy (n = 14), atrophy and apical prostate tissue (n = 1), apical/benign prostate tissue (n = 9), adenosis (n = 2), and post-atrophic hyperplasia (n = 1). Paige Prostate resulted in the identification of four additional patients whose diagnoses were upgraded from benign/suspicious to malignant. Additionally, this AI-based test provided an estimated 65.5% reduction of the diagnostic time for the material analyzed. Given its optimal sensitivity and NPV, Paige Prostate has the potential to be employed for the automated identification of patients whose histologic slides could forgo full histopathologic review. In addition to providing incremental improvements in diagnostic accuracy and efficiency, this AI-based system identified patients whose prostate cancers were not initially diagnosed by three experienced histopathologists. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Movement markers of schizophrenia: a detailed analysis of patients' gait patterns.

Motor abnormalities occur in the majority of persons with schizophrenia but are generally neglected in clinical care. Psychiatric diagnostics fail to include quantifiable motor variables and few assessment tools examine full-body movement. We assessed full-body movement during gait of 20 patients and 20 controls with motion capture technology, symptom load (PANSS, BPRS) and Neurological Soft Signs (NSS). In a data-driven analysis, participants' motion patterns were quantified and compared between groups. Resulting movement markers (MM) were correlated with the clinical assessment. We identified 16 quantifiable MM of schizophrenia. While walking, patients and controls display significant differences in movement patterns related to posture, velocity, regularity of gait as well as sway, flexibility and integration of body parts. Specifically, the adjustment of body sides, limbs and movement direction were affected. The MM remain significant when controlling for medication load. They are systematically related to NSS. Results add assessment tools, analysis methods as well as theory-independent MM to the growing body of research on motor abnormalities in schizophrenia.

Gestalt Perception and the Experience of the Social Space in Autism: A Case Study.

Phenomenological approaches suggest that the bodily presence of others has a profound influence on the experience of social spaces. This intimate relationship is particularly evident in mental disorders. Investigations into the nature of intersubjectivity in various pathologies indicate that modifications to the capacity for social perception play a key role in determining the manners in which the social space is experienced and felt. This paper aims to examine the interviewing relation of social perception and the experience of space and its consequences in autism spectrum disorder (ASD). This is done through a phenomenologically informed analysis of the functioning of social perception in ASD. Our account proposes that the atypical socio-perceptual patterns exhibited by people with autism significantly reduce the capacity to grasp the context of the situation, which facilitates and intensifies negative feelings that are intertwined with the experience of social spaces. This novel understanding draws on the idea that ASD involves a fundamental difficulty to establish a gestalt perception of social scenes. The evidence we discuss suggests that this anomaly in the operation of social perception also modulates the experience of the social space. Failing to perceive the wholeness of the situation means that people with autism often experience the social space as unfamiliar, confusing, uncertain, and unsafe, rather than feeling familiar and understood in the embodied presence of others. As a result, autistic subjects may experience difficulty evaluating the outcomes of hazardous circumstances, which poses a risk to their well-being, particularly in borderline situations. This suggestion is elaborated through the tragic occurrences that led to the killing of Eyad al-Hallaq, a 32-year-old Palestinian with autism.

Person-Centered Psychiatry as Dialogical Psychiatry: The Significance of the Therapeutic Stance.

In this article, we present holistic and person-centered perspectives in psychiatry, with the aim of better understanding what a focus on personhood might really mean and what clinical implications it might have. We first introduce classical and philosophical concepts of personhood, in order to then outline person-centered approaches in psychiatry, which mainly focus on the person of the patient. We then argue that, for it to really be person-centered, psychiatry must necessarily also focus on the person of professionals. We thus explore the notion of stance, as the expression of the therapist's personhood. By unpacking the effects that a professional's stance can have on patients, we finally turn to a consideration of the interpersonal sphere. More specifically, we propose clinical considerations on a therapeutic stance that strives to support and to help the person of the patient unfold. Such a stance must - we argue - necessarily be a dialogical one. Drawing on these considerations, we thus claim that a truly person-centered approach in psychiatry must necessarily and automatically be interperson-centered and dialogical. In the concluding remarks, we finally discuss broader societal implications and outline future research perspectives.

The disappearing body: anorexia as a conflict of embodiment.

Anorexia nervosa is often regarded primarily as a disorder of the body image, with affected individuals submitting themselves to the dictate of a predominant model of slenderness. However, even though this frequently functions as a gateway to the disorder, the paper intends to show that the actual conflict in anorexia consists in a fundamental alienation of the self from the body. In order to analyze this alienation from a phenomenological point of view, the paper introduces the polarity of lived body (body-as-subject) and physical body (body-as-object). It then explores the phenomenology of anorexia, drawing on characteristic self-reports as well as on the phenomenological, psychoanalytic and cultural science literature. The anorexic conflict of embodiment arises in adolescence, where the body becomes an object of the other's gaze in a special way. Starting with an attempt to comply with the ideal body image, the anorexic patient increasingly fights against her dependency on her body and its uncontrollable nature, above all its hunger and femininity. To be in total control of her body and to gain independence from it, becomes the source of a narcissistic triumph. Thus, in striving for autonomy and perfection, the anorexic patient alienates herself from her embodiment. This results in a radical dualism of 'mind' and 'body': pursuing the ideal of an asexual, angelic, even disappearing body. Anorexia is thus conceived as a fundamental conflict of embodiment.

Addition of shock wave therapy to nail dynamization increases the chance of long-bone non-union healing.

BACKGROUND: Long-bone non-unions after intramedullary nailing can be treated by nail dynamization or focused high-energy extracorporal shock wave therapy (fESWT). The objective of this study was to assess the effect of the combination therapy of nail dynamization and fESWT on long-bone non-unions. MATERIALS AND METHODS: 49 patients with long-bone non-unions (femur and tibia) after nailing were treated with nail dynamization (group D, n = 15), fESWT (group S, n = 17) or nail dynamization in addition to fESWT (group DS, n = 17). Patients were followed up for 6 months retrospectively. Furthermore, age, sex, Non-Union Scoring System (NUSS) score, time intervals from primary and last surgery until intervention and smoking status were analysed for their correlations to bone union. RESULTS: Union rates were 60% for group D, 64.7% for group S and 88.2% for group DS, with a significant difference between group D and DS (p = 0.024). Successful treatment was correlated with high age (OR 1.131; 95% CI 1.009-1.268; p = 0.034), female gender (OR 0.009; 95% CI 0.000-0.89; p = 0.039), low NUSS score (OR 0.839; 95% CI 0.717-0.081; p = 0.028) and negative smoking status (OR 86.018; 95% CI 3.051-2425.038; p = 0.009). CONCLUSIONS: Data from the present study indicate that the combination therapy of nail dynamization and fESWT leads to a higher union rate than dynamization or fESWT alone. LEVEL OF EVIDENCE: Level 3.

Multi-magnification-based machine learning as an ancillary tool for the pathologic assessment of shaved margins for breast carcinoma lumpectomy specimens.

The surgical margin status of breast lumpectomy specimens for invasive carcinoma and ductal carcinoma in situ (DCIS) guides clinical decisions, as positive margins are associated with higher rates of local recurrence. The "cavity shave" method of margin assessment has the benefits of allowing the surgeon to orient shaved margins intraoperatively and the pathologist to assess one inked margin per specimen. We studied whether a deep convolutional neural network, a deep multi-magnification network (DMMN), could accurately segment carcinoma from benign tissue in whole slide images (WSIs) of shave margin slides, and therefore serve as a potential screening tool to improve the efficiency of microscopic evaluation of these specimens. Applying the pretrained DMMN model, or the initial model, to a validation set of 408 WSIs (348 benign, 60 with carcinoma) achieved an area under the curve (AUC) of 0.941. After additional manual annotations and fine-tuning of the model, the updated model achieved an AUC of 0.968 with sensitivity set at 100% and corresponding specificity of 78%. We applied the initial model and updated model to a testing set of 427 WSIs (374 benign, 53 with carcinoma) which showed AUC values of 0.900 and 0.927, respectively. Using the pixel classification threshold selected from the validation set, the model achieved a sensitivity of 92% and specificity of 78%. The four false-negative classifications resulted from two small foci of DCIS (1 mm, 0.5 mm) and two foci of well-differentiated invasive carcinoma (3 mm, 1.5 mm). This proof-of-principle study demonstrates that a DMMN machine learning model can segment invasive carcinoma and DCIS in surgical margin specimens with high accuracy and has the potential to be used as a screening tool for pathologic assessment of these specimens.

Sensitization against Fungi in Patients with Airway Allergies over 20 Years in Germany.

BACKGROUND: Fungal spores are ubiquitous allergens. Severe forms of asthma are particularly highly associated with fungal sensitization. National and international asthma guidelines recommend the implementation of allergen immunotherapy if indicated. Thus, detection and treatment of relevant allergies are key components of primary care of these patients. OBJECTIVES: The aims of the study were (i) to investigate trends in the prevalence of sensitization to twelve fungi in central Germany over the last 20 years and (ii) to dissect specific sensitization patterns among the 3 most important fungi: Aspergillus, Alternaria, and Cladosporium. METHODS: This single-center study evaluated skin prick test (SPT) results of 3,358 patients with suspected airway allergies over a period of 20 years (1998-2017). RESULTS: While 19.2% of all study patients had positive test results to at least 1 of the 3 fungi (Alternaria, Aspergillus, or Cladosporium) in the first study decade, this rate increased to 22.5% in the second decade. Slight increases in sensitization rates to almost all fungi were observed over the 20-year period. In the last decade, polysensitization to Alternaria, Aspergillus, and Cladosporium increased significantly. Sensitization to fungi is age-dependent and peaks in the age-group of 21-40 years during the second decade. CONCLUSION: Fungi are relevant allergens for perennial and seasonal allergy symptoms. We currently recommend including Aspergillus, Alternaria, and Cladosporium in the standard series of SPTs for airway allergies.

Influence of nuclear spins on electron spin coherence in isolated, p-doped tin clusters.

Magnetic double deflection experiments reveal that nuclear spins diminish electron spin coherence in isolated AlSn12 clusters. A temperature-dependent fraction of the endohedral cage clusters show superatomic response in Stern-Gerlach experiments which allows one to detect spin flips under controlled conditions in a double deflection arrangement. The concentration of nuclear spins in the tin cage is varied by using isotopically enriched tin samples. Hyperfine interaction, nuclear spin statistics and spin dynamics are discussed in detail. It is demonstrated that state-interference in the multistate Landau-Zener system AlSn12 explains why the spin decoherence is significantly increased when one or two nuclear spins are already present in the cluster, while the spin coherence no longer changes significantly with the addition of further nuclear spins.

Discriminating the influence of thermal excitation and the presence of structural isomers on the Stark and Zeeman effect of AlSn12 clusters by combined electric and magnetic beam deflection experiments.

AlSn12 clusters were studied in electric and magnetic beam deflection experiments at nozzle temperatures of Tnozzle = 16-100 K. For 16 K, spatial separation of two fractions of clusters in the molecular beam was achieved by deflection with both an electric and a magnetic field gradient. In the electric deflection experiment, about 76% of the clusters are identified as non-polar and the rest as highly-polar, while the magnetic deflection experiment demonstrates that 37% show an atom-like and 63% a Brillouin-like magnetic response. In order to probe the connection between these fractions in electric and magnetic beam deflection, a combination of these two experiments was performed. This clearly demonstrates that the highly-polar clusters show a Brillouin-like magnetic response and only the non-polar clusters can be deflected atom-like in a magnetic field. This observation suggests that two structural isomers are present in the molecular beam, one of which is highly-symmetric, and demonstrates that spatial isomer separation of metal clusters containing heavy elements is feasible. However, vibrational excitation must also be taken into account to explain the observed magnetic response. A stepwise increase of the cluster temperature shows that suppression of the superatomic response is more sensitive to vibrational excitation than the quenching of the permanent electric dipole moment.

Contact sensitizations to disinfectants containing alcohols or quaternary ammonium compounds are rarely of clinical relevance.

BACKGROUND: The use of disinfectants is part of the everyday life of people, especially in the medical profession. During the coronavirus disease 2019 (COVID-19) pandemic, the use of disinfectants continues to increase and is of fundamental importance in infection control. OBJECTIVES: To determine the frequency of sensitization and the value of patch testing to didecyldimethylammonium chloride (DDAC) and the alcohols ethanol, 1-propanol, and isopropanol. METHODS: Clinical patch test data of 145 patients with suspected contact allergy to disinfectants were retrospective analysed. RESULTS: Among the 145 patients patch tested with the different alcohols, only one nurse was detected with a possible allergy to 1-propanol. Additional patch testing in 84 patients with DDAC 0.05% resulted in five patients with weakly positive reactions only, without clinical relevance. Patch testing with DDAC 0.03% showed no positive reactions at all on day 3 readings. CONCLUSIONS: DDAC and alcohols are rarely responsible for allergic contact dermatitis. The accused products of the patients should be checked for other allergens and further additives with skin-irritating properties. Individual susceptibility and mishandling of the disinfectants should be considered.