The Feline and the Swine: A Peculiar Case in an Allergy Clinic.

Cross-reactivity between mammalian proteins, such as that in Pork Cat Syndrome, remains a topic of great interest. This syndrome, characterized by an immunoglobulin E (IgE)-mediated response to porcine albumin triggered by sensitization through cat epithelium, has been sparsely documented. We discuss a 41-year-old female who developed a pruritic rash within 30 minutes of consuming pork. Notably, she exhibited elevated serum IgE levels with specific reactions to cat dander, dog dander, and pork. A skin prick test for pork was positive. The patient was treated conservatively with allergen avoidance, vitamin D supplementation, fexofenadine, and doxycycline for systemic reactions, and topical corticosteroids for localized skin reactions, yielding a resolution of symptoms. This case underscores the significance of recognizing rare cross-reactivities in allergy and immunology and the manifestations of Pork Cat Syndrome, necessitating a comprehensive patient history and awareness for improved diagnosis and management.

Ciguatera Toxin Syndrome from Amberjack Ingestion as a Cause of Chronic Dermatitis with Episodic Erythema.

Bioaccumulation of naturally produced ciguatoxin (CTX), such as that in ciguatera poisoning, continues to be a subject of great interest. In this condition, CTX is ingested by subtropical and tropical reef fish. Humans consume the fish species, and CTX is absorbed through the gastrointestinal tract and binds voltage-gated sodium channels on nerve terminals to cause neurological, gastrointestinal, cardiac, and rare dermatological clinical manifestations. In this present case, we discuss a 65-year-old female who presented with acute loose bowel movements and generalized pruritus of her anterior chest wall, abdomen, and bilateral upper and lower extremities 48 hours after consumption of amberjack fish. The patient was treated with intravenous corticosteroids and epinephrine and discharged with an oral corticosteroid taper. After appropriate treatment protocol, the patient continued to have pruritus with a burning sensation in her extremities with a rare skin dermatitis. Subsequent treatment included topical corticosteroids and moisturizing lotion to create a skin barrier, fexofenadine for pruritus control, and gabapentin and amitriptyline for paresthesia. This case demonstrates the need for continued research and patient education into the broad clinical manifestations that present as life-altering ciguatera poisoning.

A Rare Case of Sinonasal Ewing Sarcoma With Radiologic-Pathologic Correlation.

An 89-year-old male presented with syncope and worsening difficulty in breathing through the left nostril. Computed tomography demonstrated a tumor in the anterior ethmoid air cells and maxillary sinus, which extended into the frontal lobe. Magnetic resonance imaging similarly demonstrated an aggressive lesion. This mass was difficult to differentiate from more commonly seen lesions at this location such as an esthesioneuroblastoma or nasopharyngeal carcinoma. Direct visualization, biopsy, and subsequent pathologic analysis eventually confirmed the diagnosis of malignant Ewing sarcoma (EWS). Our case explores the radiological findings of EWS originating from the ethmoid sinus, compares EWS with other common carcinomas in the same location, confirms the diagnosis through pathological correlation, and investigates the prognosis and treatment of these lesions. This case highlights the importance of a multidisciplinary approach to diagnose EWS when it occurs in an atypical location. The clinical team relied on input from the radiology, surgery, ENT, neurology, and pathology departments to make an accurate diagnosis and plan treatment for this aggressive tumor.

COVID-19-Related Bilateral Avascular Necrosis of the Femoral Head.

Osteonecrosis is a pathologic process that involves focal bone infarction and death of bone tissue caused by trauma, infections, autoimmune conditions, and chronic steroid use; however, most cases go undiagnosed. The link between bilateral osteonecrosis and coronavirus disease 2019 (COVID-19) infections has not been fully investigated. This is the case of a 42-year-old Caucasian woman who presented to the emergency department for bilateral hip pain, which started three months prior. Initially, the pain was mild; however, her symptoms worsened, causing her to have difficulty ambulating. Co-incidentally she tested positive for COVID-19 10 days after the onset of pain. She denied any lower-extremity numbness, weakness, and loss of bowel or bladder function. X-ray of the hips showed significant sclerosis of bilateral femoral heads and acetabula, indicating avascular necrosis. She was given ketorolac injection intramuscularly for analgesia and remained in stable condition. Upon discharge, she was given a referral to orthopedic surgery for bilateral total hip arthroplasty. Atraumatic osteonecrosis of the femoral head can be caused by multiple etiologies, including exposure to medications, post-transplantation procedures, trauma, and hypercoagulable states. This condition is likely due to poor angiogenesis after an infarct, causing a domino effect of bone demineralization, trabecular thinning, and cortical collapse. A literature search demonstrated prior cases of unilateral femoral head necrosis associated with COVID-19 infection and steroid use. There have been no cases of bilateral osteonecrosis of the femoral head reported without long-term steroid use. Considering the disease severity in both hips and limited steroid use (only five days of prednisone), other common etiologies were sought and were ruled out. In our patient, the only event that was related to her initial onset of hip pain was a COVID-19 infection. We suggest a relationship between COVID-19 infection and avascular necrosis given the rapid progression of the disease. We acknowledge that this presentation of bilateral osteonecrosis is rare and warrants further investigation. More research should be performed to establish a tenable relationship between COVID-19 infection and osteonecrosis, with and without the use of steroids.

Uterine Anaphylaxis Due to Subcutaneous Immunotherapy (SCIT) for Inhalant Allergens: A Case Series.

Subcutaneous immunotherapy (SCIT), commonly known as "allergy shots," aims to achieve a clinical tolerance for allergens that cause symptoms of allergic rhinoconjunctivitis, allergic asthma, or insect sting allergies. Systemic reactions to SCIT are classified in severity from one organ system (grade 1) to anaphylaxis that potentially may have a fatal outcome (grade 5). Uterine cramps fall under grade 2, and they are rarely reported during SCIT. In this study, we report four cases of uterine anaphylaxis following SCIT for environmental allergens with symptoms such as severe lower abdominal cramping resembling menstrual cramps. Patients also experienced urticaria, angioedema, diffuse erythema, and flushing. None of the patients experienced uterine bleeding. To the best of our knowledge, this is the largest case series reporting this reaction to SCIT. We accompany this finding with a review of the literature on this rare but interesting topic.

Chronic Urticaria Suspected to be Caused by a 13.5 mg Levonorgestrel Intrauterine Device (Skyla®).

Chronic urticaria (CU) is a hive-like rash lasting over six weeks. Common associations include low vitamin D, thyroid autoantibodies, and Helicobacter pylori (H. pylori) infection, among others. Progesterone has been documented to trigger CU, by endogenous or exogenous progesterone. The use of intrauterine devices (IUDs) has been a popular source of birth control, with many containing progesterone. Although rarely reported, some patients have been seen to have an urticarial reaction after implantation of an IUD. Here, we present a case of a patient with progesterone-induced chronic urticaria, likely triggered by implantation of a 13.5 mg intrauterine device implant (Skyla®, Bayer, Whippany, NJ, USA). To the best of our knowledge, this is the first case to report the association between Skyla® and chronic urticaria.

Bilateral Optic Disk Swelling and Peripheral Visual Field Defects as a Rare Initial Presentation of Primary Chiari I Malformation.

Chiari malformation 1 (CM1) is defined as a herniation of encephalon matter through the base of the skull. The amount of herniation is cited as greater than 3 mm or 5 mm, depending on the source of literature. We report a rare case of a 55-year-old male initially presenting with bilateral papilledema and monocular right lower quadrantanopia, found to have CM1. An MRI confirmed 4.87 mm herniation of the cerebellar tonsils at the foramen magnum, and he was diagnosed with CM1. He was later found to have a normal opening pressure on lumbar puncture at 10 cm H2O. This poses an interesting clinical question as papilledema is defined by elevated intracranial pressure. The ophthalmic defects of this patient with normal intracranial pressure and CM1 are explored in this report.

A 20.5 cm Malignant Peripheral Nerve Sheath Tumor of the Anterior Mediastinum Showing Response to Neoadjuvant Therapy.

Malignant peripheral nerve sheath tumors (MPNST) are a rare form of sarcoma derived from Schwann cells. Major risk factors for development are neurofibromatosis 1 (NF1) and prior radiation exposure. Tumor location is highly variable. We present a case of an extremely large MPNST tumor in the anterior mediastinum in a 66-year-old male. To the best of our knowledge, the 20.5 cm tumor is the first of its kind in a patient without clinical signs of NF1 or prior radiation exposure. The localization of this tumor to the anterior mediastinum is rarer, as the most common tumors presenting in this area are thyroid neoplasms, thymomas, teratomas, and lymphomas. The patient's tumor responded to doxorubicin-ifosfamide-mesna-based therapy. The tumor decreased from 20.5 cm to 9.0 cm on subsequent imaging. Thus, this is an interesting and valuable case to learn about the presentation and potential treatments of such a rare pathology.

Deep Brain Stimulation as a Treatment for Refractory Epilepsy: Review of the Current State-of-the-Art.

Epilepsy affects ∼ 1% of the global population, and 33% of patients are nonresponsive to medication and must seek alternative treatment options. Alternative options such as surgery and ablation exist but are not appropriate treatment plans for some patients. Neurostimulation methods such as vagal nerve stimulation, responsive neural stimulation, and deep brain stimulation (DBS) are viable alternatives for medically refractory patients. DBS stimulation has been used in the treatment of Parkinson's disease, dystonia, and pain management. For the treatment of epilepsy, DBS has been found to be an effective treatment plan, with promising results of reduced seizure frequency and intensity. In this review, we discuss DBS surgery and equipment, mechanisms of DBS for epilepsy, and efficacy, technological specifications, and suggestions for future research. We also review a historical summary of experiments involving DBS for epilepsy. Our literature review suggests that further studies are warranted for medically refractory epilepsy using DBS.

Deep Learning in Gastrointestinal Endoscopy.

Gastrointestinal (GI) endoscopy is used to inspect the lumen or interior of the GI tract for several purposes, including, (1) making a clinical diagnosis, in real time, based on the visual appearances; (2) taking targeted tissue samples for subsequent histopathological examination; and (3) in some cases, performing therapeutic interventions targeted at specific lesions. GI endoscopy is therefore predicated on the assumption that the operator-the endoscopist-is able to identify and characterize abnormalities or lesions accurately and reproducibly. However, as in other areas of clinical medicine, such as histopathology and radiology, many studies have documented marked interobserver and intraobserver variability in lesion recognition. Thus, there is a clear need and opportunity for techniques or methodologies that will enhance the quality of lesion recognition and diagnosis and improve the outcomes of GI endoscopy. Deep learning models provide a basis to make better clinical decisions in medical image analysis. Biomedical image segmentation, classification, and registration can be improved with deep learning. Recent evidence suggests that the application of deep learning methods to medical image analysis can contribute significantly to computer-aided diagnosis. Deep learning models are usually considered to be more flexible and provide reliable solutions for image analysis problems compared to conventional computer vision models. The use of fast computers offers the possibility of real-time support that is important for endoscopic diagnosis, which has to be made in real time. Advanced graphics processing units and cloud computing have also favored the use of machine learning, and more particularly, deep learning for patient care. This paper reviews the rapidly evolving literature on the feasibility of applying deep learning algorithms to endoscopic imaging.