The review, conducted according to the PRISMA-ScR guidelines for scoping reviews, screened 1,936 records and ultimately included 27 studies that examined children and adolescents whose diagnosis was delayed, missed, or changed from one type of diabetes to another. The researchers used a population-concept-context framework to decide which studies qualified, focusing on three distinct scenarios: children whose type 1 diabetes diagnosis came late, children whose initial diagnosis was wrong at the first medical encounter, and children whose diabetes was initially classified as a different type altogether. This structure allowed the team to separate the different kinds of diagnostic failure that can occur on the long road from first symptoms to correct treatment.

The technical picture that emerges is one of striking heterogeneity. For newly diagnosed type 1 diabetes, the frequency of delayed diagnosis ranged from 14.1 to 46.6 percent in studies that did not stratify results by ketoacidosis status. When the analysis separated children by whether they had developed diabetic ketoacidosis, the most dangerous acute complication of the disease, the ranges diverged sharply: 55.0 to 58.7 percent among children without ketoacidosis, and a staggering 43.0 to 98.1 percent among those with it. In other words, children who ended up in the most life-threatening state were often those whose diagnosis had been missed the longest, allowing insulin deficiency to progress unchecked until the body began breaking down fat for fuel and accumulating acidic ketones in the blood.

Missed diagnosis at the first healthcare contact followed a similar pattern. Across studies without stratification by ketoacidosis status, 16.0 to 38.7 percent of children were sent home or otherwise misdiagnosed at their initial encounter. Among children who did not develop ketoacidosis, the range was 5.0 to 34.8 percent, while among those who did, it spanned from 0.6 to as high as 72.0 percent. The enormous variability, the authors stress, reflects real differences in populations, healthcare settings, definitions of delay, and the methods used to ascertain diagnostic error, rather than a single universal failure rate. A retrospective chart review in one country may count delay differently than a prospective cohort in another, which makes direct comparison difficult even when the underlying clinical problem is the same.

Beyond delays in recognizing type 1 diabetes itself, the review also quantified how often children are assigned the wrong type of diabetes. Misclassification between type 1 and type 2 diabetes occurred in 1.4 to 22.7 percent of cases across the included studies. This matters because the two diseases demand fundamentally different management: type 1 diabetes requires immediate and lifelong insulin replacement, while type 2 diabetes in adolescents may initially be managed with lifestyle changes and oral agents. A child with type 1 diabetes mistakenly treated as type 2 can deteriorate rapidly, and the review found that misdiagnosis was indeed associated with errors in management and an increased risk of adverse events.

The review also documented rarer but clinically important diagnostic revisions. In a population of patients with atypical presentations of type 1 diabetes, 11.6 percent were subsequently reclassified as having maturity-onset diabetes of the young, a monogenic form of diabetes caused by mutations in single genes that affect insulin-producing beta cells. In a cohort of patients initially diagnosed with type 1 diabetes, 4.58 percent were ultimately found to have Wolfram syndrome, a rare genetic disorder that combines diabetes with optic atrophy, deafness, and other neurological features. These figures underscore why the studies that addressed diabetes classification relied on diagnostic protocols and algorithms, and performed genetic testing, to arrive at the correct label. Monogenic diabetes, in particular, can masquerade as type 1 diabetes for years, and identifying it changes prognosis, family counseling, and sometimes treatment entirely.

So where do the errors actually happen? The review identified the most frequent mistakes made by healthcare professionals as the omission or misinterpretation of clinical symptoms and improper handling of laboratory examinations. The classic warning signs of type 1 diabetes in children, including excessive thirst, frequent urination, unexplained weight loss, and fatigue, can be subtle in their early stages and easily attributed to more benign causes such as urinary tract infections, viral illnesses, or behavioral changes. Laboratory findings can compound the confusion: a mildly elevated blood glucose may be dismissed as a laboratory artifact or a stress response, and glycosylated haemoglobin values may not yet reflect the rapid metabolic deterioration of new-onset disease.

The consequences of these errors are not abstract. Diabetic ketoacidosis at diagnosis is associated with longer hospital stays, admission to paediatric intensive care units, and potential long-term effects on the developing brain, since severe ketosis and cerebral edema can leave lasting neurological damage. Children who are misdiagnosed with type 2 diabetes and started on inappropriate therapy may experience worsening hyperglycemia and a more abrupt, more dangerous onset of insulin dependence. The review’s finding that misdiagnosis was linked to management errors and adverse events gives quantitative weight to what paediatric endocrinologists have long argued: the window between first symptoms and correct diagnosis is a critical period in which the entire trajectory of the disease can be shaped.

The authors are careful about the limits of their evidence. Because the included studies differed so widely in populations, settings, definitions, and ascertainment methods, the reported frequencies of missed recognition, diagnostic delay, and misclassification vary markedly, and no single figure can be treated as a universal benchmark. A scoping review, by design, maps the breadth of existing literature rather than pooling it into a single estimate, and the 27 included studies represent a heterogeneous mix of prospective cohorts, retrospective cohorts, and cross-sectional designs from different healthcare systems. What the review does establish is that these diagnostic failures are not rare curiosities but recurring features of paediatric diabetes care across multiple countries and settings.

The practical implications are clear. Raising awareness of the classic symptom cluster among primary care providers, parents, and school health staff could shorten the delay between first symptoms and first test. Simple protocols, such as checking blood glucose in any child presenting with unexplained thirst, urination, or weight loss, could catch cases before ketoacidosis develops. And for children whose diabetes does not behave as expected, structured diagnostic algorithms and access to genetic testing for monogenic forms such as maturity-onset diabetes of the young and Wolfram syndrome could prevent years of misdirected treatment. As the incidence of type 1 diabetes in children continues to rise worldwide, the review serves as both a warning and a roadmap: the tools for earlier, more accurate diagnosis already exist, and the evidence now shows exactly how much is at stake when they are not used.

Subject of Research: Delayed diagnosis and misdiagnosis of type 1 diabetes in children and adolescents

Article Title: Delayed diagnosis and misdiagnosis of type 1 diabetes in children and adolescents: a scoping review

Article References: Giza, S., Fedi, L., Schierloh, U., Fagherazzi, G., de Beaufort, C., & Aguayo, G. A. (2026). Delayed diagnosis and misdiagnosis of type 1 diabetes in children and adolescents: a scoping review. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07808-0

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07808-0

Keywords: type 1 diabetes, children, adolescents, delayed diagnosis, misdiagnosis, diabetic ketoacidosis, misclassification, MODY, Wolfram syndrome, scoping review, paediatric care, diagnostic errors

The study, conducted by Joseph McGrath, Evelyn Fagan, Kaeli Samson, Yue Zhan, and Adam Sutton, was approved by the University of Nebraska Medical Center’s institutional review board and carried out in accordance with the Declaration of Helsinki, with written informed consent obtained from every participant. The research team set out to systematically compare what patients say about their own skin lesion histories against clinical verification, a comparison that matters enormously because the entire architecture of skin cancer surveillance in many health systems rests on self-reported data gathered in intake questionnaires and verbal histories.

Actinic keratoses are rough, scaly patches that develop on chronically sun-exposed skin, most often in fair-skinned, older adults. They are technically keratinocyte dysplasias rather than frank malignancies, but they occupy a critical position on the continuum of cutaneous carcinogenesis. A subset of them can progress to squamous cell carcinoma, and their presence signals what dermatologists call field cancerization, a state in which broad swathes of skin have sustained enough ultraviolet damage that multiple lesions can arise simultaneously and independently across the affected area. Keratinocyte carcinomas, meanwhile, encompass basal cell carcinoma and squamous cell carcinoma, the two most frequent cancers in fair-skinned populations worldwide and cancers whose incidence continues to climb as populations age and cumulative ultraviolet exposure accumulates.

The problem with relying on patient recall for these conditions is baked into their biology and their clinical course. Actinic keratoses are frequently treated with destructive methods such as cryotherapy, in which liquid nitrogen obliterates the lesion without any tissue being sent to a pathology laboratory. A patient who has had a dozen such treatments over twenty years may genuinely not know whether any given rough patch was confirmed as an actinic keratosis, whether it was something benign like a seborrheic keratosis, or whether it was an early squamous cell carcinoma that was frozen off preemptively. The diagnostic label often exists only in billing codes or in the memory of a clinician the patient saw years ago, if it exists at all.

Keratinocyte carcinomas present a related but distinct recall challenge. Basal cell carcinomas are rarely life-threatening but frequently recur, and patients with one history of nonmelanoma skin cancer face substantially elevated odds of developing subsequent lesions, a relationship established in meta-analytic work going back to Marcil and Stern’s widely cited 2000 review in the Archives of Dermatology. Squamous cell carcinomas carry greater metastatic potential, making accurate history-taking even more consequential. If a patient underreports a prior squamous cell carcinoma, a clinician may underestimate risk and calibrate follow-up too loosely. If a patient overreports, the result can be unnecessary anxiety, redundant biopsies, and wasted health system resources. Either direction of error degrades the precision of epidemiological studies that depend on self-reported cancer histories as their exposure variable.

This is not the first time the validity of patient self-report in dermatology has been scrutinized. A landmark 2004 study by Ming and colleagues, published in the same Archives of Dermatology, examined the validity of patient self-reported history of skin cancer and found meaningful discordance between what patients reported and what medical records could substantiate. That work, along with the more recent effort by Kitrell, Crew, Wysong, and Sutton in 2023 to refine the classification of field cancerization, frames the conceptual backdrop against which the new Nebraska-led study operates. The field cancerization concept itself, originally coined in the head and neck oncology literature and since extended to sun-damaged skin, implies that patients with field disease are precisely the ones most likely to have long, complicated lesion histories that strain the limits of lay recall.

Health literacy adds another layer of complexity. A 2024 systematic review by Chang and colleagues in the Journal of Prevention examined the role of health literacy in skin cancer preventive behavior and highlighted how unevenly patients understand even basic distinctions between lesion types. Many patients use the phrase skin cancer loosely, applying it to anything their doctor froze, burned, or scraped. Others with genuine histories of malignancy may not register the diagnosis because the encounter was brief, the terminology was unfamiliar, or the lesion was treated in a setting where pathology confirmation never occurred. In epidemiological surveys, in genetic studies recruiting participants on the basis of skin cancer history, and in clinical trials of field therapies, these misclassifications propagate quietly through the data.

The methodological stakes extend beyond the clinic into the research enterprise itself. Countless studies of keratinocyte carcinoma risk factors, from tanning bed use to immunosuppression to genetic susceptibility loci, rely on questionnaires asking participants whether a physician has ever told them they had skin cancer. Validation studies like the one from the University of Nebraska team provide the sensitivity and specificity estimates that allow researchers to correct for misclassification statistically. Without such grounding, effect estimates can be biased toward or away from the null in unpredictable ways, and the direction of bias often differs for actinic keratoses, which are over-reported when patients conflate them with benign barnacles of aging, versus keratinocyte carcinomas, which may be under-reported when pathology confirmation was never communicated clearly.

The practical implications for clinical practice are equally significant. Dermatologists performing surveillance on patients with a history of field cancerization already know that these individuals require more frequent examinations, and the new findings underscore that the history a patient volunteers should be treated as a starting point rather than a settled fact. Wherever possible, clinicians and researchers seeking accurate keratinocyte carcinoma histories should corroborate patient report with pathology records, tumor registries, or prior biopsy reports. For actinic keratoses, where confirmation is often impossible because destructive treatment leaves no tissue to examine, the study’s findings argue for building explicit uncertainty into both clinical documentation and research instruments, perhaps by distinguishing between patient-recalled lesions and provider-diagnosed, pathology-confirmed ones.

What makes this research letter notable is not that it overturns any single dogma but that it quantifies a vulnerability running through a vast body of dermatological science and everyday clinical care. The authors, who declare no competing interests and report no external funding, designed the study so that statistical analysis was performed by dedicated biostatisticians within the University of Nebraska Medical Center’s Department of Biostatistics, with McGrath and Fagan contributing equally to the work. Their data cannot be shared openly, a restriction that protects participant privacy under the informed consent agreements patients signed. As skin cancer incidence continues to rise and as health systems increasingly depend on patient-reported outcomes and self-administered intake tools, including digital questionnaires and telehealth screening algorithms, the gap between what patients believe about their own skin and what has actually occurred on it becomes a variable that medicine can no longer afford to ignore. This study is a measured, careful reminder that in dermatology, as in much of medicine, the patient’s memory is a diagnostic instrument, and like any instrument, it needs calibration.

Subject of Research: Accuracy of patient-reported histories of actinic keratoses and keratinocyte carcinomas

Article Title: Assessing the accuracy of patient-reported actinic keratoses and keratinocyte carcinomas

Article References: McGrath, J., Fagan, E., Samson, K., Zhan, Y., & Sutton, A. (2026). Assessing the accuracy of patient-reported actinic keratoses and keratinocyte carcinomas. Archives of Dermatological Research, 318(1), Article 489. https://doi.org/10.1007/s00403-026-04942-8

Image Credits: AI Generated

DOI: 10.1007/s00403-026-04942-8

Keywords: actinic keratosis, keratinocyte carcinoma, skin cancer, patient self-report, dermatology, field cancerization, basal cell carcinoma, squamous cell carcinoma, health literacy, misclassification, skin cancer screening, epidemiology