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Mycotoxins and Tick-Borne Disease
Published in Sahar Swidan, Matthew Bennett, Advanced Therapeutics in Pain Medicine, 2020
The definitive diagnosis of Lyme disease can be daunting for several reasons. As mentioned previously, the clinical manifestations can be varied in timing and may involve multiple bodily systems. The presence of a classical erythema migrans rash following a tick bite is considered pathognomonic, but the rash may vary in appearance. About 70–80% of patients develop this rash, but the appearance may vary, and it is recognized that only about 10% of patients with erythema migrans get a classic “target lesion.”16 The incubation between tick bite and the lesion may be as long as 30 days. It is also well known that only 50–70% of patients recall being bitten by a tick prior to diagnosis.17
Physical Exam Clues and Their Mimics in Infectious Diseases in the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Under the best of circumstances, the physical examination (PE) of an CCU patient is quite challenging. To make matters more difficult, many physical findings are neither specific nor sensitive. What have been touted as “pathognomonic” findings are rarely, if ever, so. The astute physician must always consider that a given PE finding may be due to more than one disease entity. Premature closure and availability bias can further trip up the unwary clinician. As with various clinical syndromes, PE findings in infected patients can be mimicked by a variety of non-infectious diseases. The table that follows lists many of the PE findings one may encounter in the infected CCU patient, along with their non-infectious mimics and hints to help distinguish them apart.
Diagnostic strategy
Published in Caroline J Rodgers, Richard Harrington, Helping Hands: An Introduction to Diagnostic Strategy and Clinical Reasoning, 2019
Caroline J Rodgers, Richard Harrington
Pathognomonic signs and symptoms are those which are specifically indicative of a particular condition. Care needs to be exercised here, and it is best to have an appreciation of the positive predictive value of signs and symptoms rather than relying on a list of those which are deemed pathognomonic. For example, Koplik’s spots (white lesions on the buccal mucosa) have long been described as pathognomonic of measles.8 However, Koplik’s spots have since been described in echovirus and parvovirus B19 illnesses.9 Zenner and Nacul’s study of measles cases in the UK found that if Koplik’s spots were used as a diagnostic tool, the positive predictive value for a confirmed diagnosis of measles across hospital and primary care settings was 80%.9 Hence Koplik’s spots are a highly predictive (but not pathognomonic) finding for measles, and the authors suggest that if they are present in a case of suspected measles, the case should be treated as ‘probable measles’.9
The Eyes Have It: How Critical are Ophthalmic Findings to the Diagnosis of Pediatric Abusive Head Trauma?
Published in Seminars in Ophthalmology, 2023
Cynthia K Harris, Anna M Stagner
Perhaps simplistically, the trends in discussion of AHT can be summarized akin to the swinging of a pendulum. When first described, AHT was immediately embraced with belief in the pathognomonic nature of its findings. Then, some decades later, the pendulum swung hard in the opposite direction, with many medical professionals and lawyers arguing that the findings were common, non-specific, and insufficient to render such a significant diagnosis. At the heart of this controversy is a simple question: How certain of a diagnosis must one be? While the legal system may be more accustomed to binary decisions like “guilty” and “not guilty,” medicine deals in probabilities all the time. Few entities have truly pathognomonic findings, and most often a diagnosis is reached because it is the best available explanation for the findings.
The early history of the knee-jerk reflex in neurology
Published in Journal of the History of the Neurosciences, 2022
There were also those—such as Gowers, Bramwell, and Foster in England and Beard in America—who made it clear that diagnosis could not be based on localized signs alone, and that no one symptom of a disease can be diagnostic (Gowers 1879b). Although reflexes were useful in forming a diagnosis, they were certainly not all of it. Beard (1879, 245) was quite explicit: There is no one symptom of the disease that can be said to be diagnostic. It is by taking a survey of all these symptoms, and by studying them in their relation to each other and to the history of the case that we are able to make out the diagnosis … pathognomonic symptoms belong to lecture-rooms and text-books, not to practical experience.
Diffuse Phlebitis in Patients with Syphilitic Outer Retinopathy
Published in Ocular Immunology and Inflammation, 2021
Ocular syphilis may present with vast variation of manifestation, including interstitial keratitis, vitritis, iritis, keratic precipitates, focal retinitis, periphlebitis, papillitis, serous exudative retinal detachments, and acute syphilitic posterior placoid chorioretinopathy. The lack of pathognomonic feature makes the diagnosis difficult. High level of suspicion is required for timely diagnosis. Ocular syphilis affecting outer retina typically presents with a yellow placoid macular lesion. The condition was first described by Gass in 1990 and was termed “acute syphilitic posterior placoid chorioretinopathy (ASPPC).” In 2014, Lima1 reported two cases of ocular syphilis affecting outer retina that presented with subtle fundus finding, mild vitreous inflammation, and focal hyperautofluorescence in FAF, corresponding to area of ellipsoid zone disruption in SD-OCT. These features are similar to presentation of AZOOR. Contrary to previous reports with ASPPC, fundus finding in these cases was subtle without typical yellow placoid lesions. He referred to the condition as “syphilitic outer retinopathy.” Kim2 reported a similar case in the same year. Saleh3 reported three cases in 2017. To our knowledge, these three articles are the only publication regarding cases of syphilitic outer retinopathy in literature to date.