Herpes zoster (HZ) typically presents following reactivation of latent varicella-zoster virus (VZV) in adult and geriatric patients with a history of prior varicella infection. Primary VZV infection in patients compliant with vaccine schedules and without any immunocompromising condition is rare, with reactivation leading to HZ being even rarer. This case report details one such example involving a 13-year-old immunocompetent and fully immunized male with HZ despite no history of VZV infection, as well as possible explanatory mechanisms for this uncommon presentation. This case report contributes to a growing body of literature on atypical HZ presentations in pediatric populations without any history of prior VZV infection or exposure.

UNASSIGNED: The persistence of diagnostic errors, despite advances in medical knowledge and diagnostics, highlights the importance of understanding atypical disease presentations and their contribution to mortality and morbidity. Artificial intelligence (AI), particularly generative pre-trained transformers like GPT-4, holds promise for improving diagnostic accuracy, but requires further exploration in handling atypical presentations.
UNASSIGNED: This study aimed to assess the diagnostic accuracy of ChatGPT in generating differential diagnoses for atypical presentations of common diseases, with a focus on the model\'s reliance on patient history during the diagnostic process.
UNASSIGNED: We used 25 clinical vignettes from the Journal of Generalist Medicine characterizing atypical manifestations of common diseases. Two general medicine physicians categorized the cases based on atypicality. ChatGPT was then used to generate differential diagnoses based on the clinical information provided. The concordance between AI-generated and final diagnoses was measured, with a focus on the top-ranked disease (top 1) and the top 5 differential diagnoses (top 5).
UNASSIGNED: ChatGPT\'s diagnostic accuracy decreased with an increase in atypical presentation. For category 1 (C1) cases, the concordance rates were 17% (n=1) for the top 1 and 67% (n=4) for the top 5. Categories 3 (C3) and 4 (C4) showed a 0% concordance for top 1 and markedly lower rates for the top 5, indicating difficulties in handling highly atypical cases. The χ2 test revealed no significant difference in the top 1 differential diagnosis accuracy between less atypical (C1+C2) and more atypical (C3+C4) groups (χ²1=2.07; n=25; P=.13). However, a significant difference was found in the top 5 analyses, with less atypical cases showing higher accuracy (χ²1=4.01; n=25; P=.048).
UNASSIGNED: ChatGPT-4 demonstrates potential as an auxiliary tool for diagnosing typical and mildly atypical presentations of common diseases. However, its performance declines with greater atypicality. The study findings underscore the need for AI systems to encompass a broader range of linguistic capabilities, cultural understanding, and diverse clinical scenarios to improve diagnostic utility in real-world settings.

BACKGROUND: Autonomic nervous system dysfunction in diabetic patients can result in an atypical presentation of cardiovascular disease that can be missed. We aimed to use single-photon emission computed tomography (SPECT) to assess cardiovascular disease (CAD) in diabetic patients with atypical pain to determine whether the pain above reflects the CAD.
METHODS: Diabetic patients with atypical cardiac symptoms were referred to the SPECT department. Demographic data such as age, gender, diabetes status, and other underlying diseases were gathered. A myocardial perfusion scan was then performed. The results were recorded to evaluate the risk of myocardial ischemia and the degree of coronary artery involvement in a non-invasive manner.
RESULTS: The study included 222 (177 female) subjects with mean ages of 63.01±11.62 and 59.41±9.19 in positive and negative SPECT, respectively. The most common symptoms were atypical chest pain (51.8%), followed by shortness of breath (50.5%), nausea, and syncope (0.9%). Cardiac parameters, such as the summed stress score (SSS), summed rest score (SRS), total perfusion deficit in stress (TPD-s), total perfusion deficit in rest (TPD-r), were significantly higher in the group with coronary artery involvement (P<0.001). However, ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volumes (ESV) parameters were not (P=.0.328, 0.351, and 0.443, respectively).
CONCLUSIONS: The mere presence of diabetes does not necessitate any additional diagnostic tests beyond those required for the general population, and it is possible to follow a diagnostic course similar to that of the general population.

Toxic megacolon denotes an abrupt non-obstructive distension of the colon, accompanied by systemic signs of toxicity. Mortality rates can soar as high as 7.9%. While primarily linked with chronic bowel conditions, the incidence attributed to Clostridioides difficile has surged due to the indiscriminate use of broad-spectrum antibiotics. Surgical intervention becomes necessary in the majority of cases. Herein, we illustrate the case of a 50-year-old female presenting with episodic epigastric pain lasting 9 h, vomiting, and watery bowel movements, devoid of peritoneal irritation findings and lacking a history of chronic intestinal inflammation. Under certain circumstances, toxic megacolon may manifest atypically, underscoring the importance of conducting a comprehensive medical history and clinical assessment. Moreover, it is imperative to solicit pertinent paraclinical investigations to address the patient holistically and foster a favorable clinical outcome.

Breast cancer is considered one of the most common cancers worldwide. The most common sites for breast cancer to metastasize are the lymph nodes, bones, lungs, brain, and liver. Involvement of the gastrointestinal tract is uncommon, and metastasis to the appendix is rare. We report a case involving a 43-year-old woman with no previous history of malignancy who presented with acute appendicitis and underwent laparoscopic appendectomy, with the final histopathological assessment revealing metastatic breast cancer.

BACKGROUND: Leptospirosis presents with highly variable clinical manifestations affecting different organ systems in different individuals. The presentation ranges from an asymptomatic or mild disease to a severe disease associated with multiorgan failure and higher mortality. Leptospirosis is highly underreported due to a lack of diagnostic modalities and less suspicion among clinicians.
METHODS: We present this single-center retrospective case series of 12 cases, which include various common and uncommon scenarios by which the disease can present and can be missed due to lack of suspicion. The study contains individual patient characteristics including demographic, laboratory, clinical, and treatment data. The association between these variables and mortality was analyzed using p-values and results were described. A p-value of<0.05 was considered statistically significant.
RESULTS: A total of 12 cases were included in the study. The male-to-female ratio was 3:1. The mean age was higher (37.75±9.81 years) in cases who died than those who recovered (34.25±14.09). Factors like history of alcoholism, presence of chronic liver disease (CLD), jaundice, acute renal failure, requirement of dialysis, and requirement of intensive care were significantly associated with increased risk of death (odds ratio >1, p-value <0.05). The most common symptom of presentation was fever in 11 (91.66%) cases. Jaundice and renal failure were significantly associated with death (odds ratio 1.2, p-value 0.04). The requirement of intensive care treatment (odds ratio 2.1, p-value 0.05) and dialysis (odds ratio 39.66, p-value 0.03) were also significantly associated with death. The percentage of death was lower in the group of patients who received combination antibiotic therapy.
CONCLUSIONS: Leptospirosis has varied presentations in different individuals and the diagnosis can be missed due to lack of specific signs and symptoms. Severe diseases involving multiple organs and preexisting comorbidities are associated with higher mortality rates. Timely diagnosis and treatment are necessary to reduce mortality and increase survival.

BACKGROUND: Atypical presentations have been increasingly recognized as a significant contributing factor to diagnostic errors in internal medicine. However, research to address associations between atypical presentations and diagnostic errors has not been evaluated due to the lack of widely applicable definitions and criteria for what is considered an atypical presentation.
OBJECTIVE: The aim of the study is to describe how atypical presentations are defined and measured in studies of diagnostic errors in internal medicine and use this new information to develop new criteria to identify atypical presentations at high risk for diagnostic errors.
METHODS: This study will follow an established framework for conducting scoping reviews. Inclusion criteria are developed according to the participants, concept, and context framework. This review will consider studies that fulfill all of the following criteria: include adult patients (participants); explore the association between atypical presentations and diagnostic errors using any definition, criteria, or measurement to identify atypical presentations and diagnostic errors (concept); and focus on internal medicine (context). Regarding the type of sources, this scoping review will consider quantitative, qualitative, and mixed methods study designs; systematic reviews; and opinion papers for inclusion. Case reports, case series, and conference abstracts will be excluded. The data will be extracted through MEDLINE, Web of Science, CINAHL, Embase, Cochrane Library, and Google Scholar searches. No limits will be applied to language, and papers indexed from database inception to December 31, 2023, will be included. Two independent reviewers (YH and RK) will conduct study selection and data extraction. The data extracted will include specific details about the patient characteristics (eg, age, sex, and disease), the definitions and measuring methods for atypical presentations and diagnostic errors, clinical settings (eg, department and outpatient or inpatient), type of evidence source, and the association between atypical presentations and diagnostic errors relevant to the review question. The extracted data will be presented in tabular format with descriptive statistics, allowing us to identify the key components or types of atypical presentations and develop new criteria to identify atypical presentations for future studies of diagnostic errors. Developing the new criteria will follow guidance for a basic qualitative content analysis with an inductive approach.
RESULTS: As of January 2024, a literature search through multiple databases is ongoing. We will complete this study by December 2024.
CONCLUSIONS: This scoping review aims to provide rigorous evidence to develop new criteria to identify atypical presentations at high risk for diagnostic errors in internal medicine. Such criteria could facilitate the development of a comprehensive conceptual model to understand the associations between atypical presentations and diagnostic errors in internal medicine.
BACKGROUND: Open Science Framework; www.osf.io/27d5m.
UNASSIGNED: DERR1-10.2196/56933.

BACKGROUND: Central centrifugal cicatricial alopecia (CCCA) nomenclature describes a typical clinical presentation of cicatricial hair loss that begins on the vertex scalp with progressive, symmetric, and centrifugal evolution. However, atypical presentations have been noted clinically by the authors and reported in the literature.
OBJECTIVE: We sought to characterize the distribution of hair loss in published cases of adult patients with CCCA.
METHODS: A 3-step search process was used to evaluate research articles in Cumulative Index to Nursing & Allied Health, EMBASE, Google Scholar, MEDLINE, Scopus, and Web of Science databases. Studies with scalp photography or description of hair loss distribution were included. Three researchers evaluated eligible studies for clinical subtypes. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review was used to report results.
RESULTS: Ninety-nine studies consisting of 281 cases of CCCA were included. Hair loss distributions included variants of the classic presentation along with distinct subtypes such as patchy, occipital, parietal, frontal, temporal, and trichorrhexis.
CONCLUSIONS: Studies had significant homogeneity, as the classic distribution of CCCA was commonly reported. Additionally, clinically diagnosed cases may have concurrent diagnoses, and numerous studies did not report trichoscopy findings.
CONCLUSIONS: CCCA terminology may not always be reflective of clinical presentation. Understanding atypical presentations is essential to inform appropriate and targeted treatment.

Typhoid fever, also known as enteric fever, is a multisystemic infection primarily caused by Salmonella enterica serotype Typhi, and less commonly by Salmonella enterica serotypes Paratyphi A, B, and C. The classic presentation includes fever, malaise, diffuse abdominal pain, and constipation. If left untreated, typhoid fever can progress to delirium, obtundation, intestinal haemorrhage, bowel perforation, and death within a month of onset. However, the clinical course can deviate from the classic stepladder fever pattern, which now occurs in as few as 12% of cases.1 In this report, we describe an atypical presentation as sensorineural hearing loss in an otherwise healthy young male.

UNASSIGNED: The objective of this study was to investigate the differences in presenting symptoms between patients with and without diabetes being diagnosed with an acute myocardial infarction (AMI).
UNASSIGNED: A total of 5,900 patients with a first-time AMI were included into the analysis. All patients aged between 25 and 84 years were recorded by the population-based Myocardial Infarction Registry in Augsburg, Germany, between 2010 and 2017. The presence (yes/no) of 12 AMI typical symptoms during the acute event was assessed within the scope of a face-to-face interview. Multivariable adjusted logistic regression models were calculated to analyze the associations between presenting symptoms and diabetes mellitus in AMI patients.
UNASSIGNED: Patients with diabetes had significantly less frequent typical pain symptoms, including typical chest pain. Also, other symptoms like sweating, vomiting/nausea, dizziness/vertigo and fear of death/feeling of annihilation occurred significantly more likely in non-diabetic patients. The only exception was the symptom of shortness of breath, which was found significantly more often in patients with diabetes. In multivariable-adjusted regression models, however, the observed effects were attenuated. In patients younger than 55 years, the associations between diabetes and various symptoms were mainly missing.
UNASSIGNED: Type 2 diabetes mellitus is a risk factor not only for the development of AMI, but is also associated with an adverse outcome after AMI. Atypical clinical presentation additionally complicates the diagnostic process. It is therefore essential for physicians to be aware of the more often atypical symptoms that diabetic AMI patients report.