Thelansis

 Yellow fever is an acute viral hemorrhagic disease caused by the flavivirus, closely related to the viruses that cause West Nile, St. Louis, and Japanese encephalitis. Tree-hole breeding mosquitoes, such as Aedes aegypti and Haemagogous species, primarily transmit it. The transmission of the virus occurs in three distinct cycles: jungle, intermediate, and urban. The incubation period is typically 3 to 6 days, and once contracted, the virus quickly spreads to multiple organs in the body, with the liver and kidneys being the most affected. Symptoms include jaundice, acute renal failure, black vomit, cerebral edema, and encephalopathy. There is no specific treatment for yellow fever, but severe cases require aggressive supportive care and hydration. The differential diagnosis for yellow fever includes a variety of other infectious diseases, such as viral hemorrhagic fevers, viral hepatitis, and malaria. Most cases of yellow fever are subclinical or mildly symptomatic, with an excellent p

 X-linked ichthyosis (XLI) is a skin disorder caused by a genetic deficiency in the STS gene located on the X chromosome. This leads to abnormal shedding of the skin, resulting in dry and scaly skin with polygonal scales. The condition is typically diagnosed in the first year of life, with some cases manifesting at birth. However, the flexures, palms, and soles remain unaffected, as do the hair and nails. Most XLI patients have partial or complete deletions of the STS gene, resulting in extensive scaling. However, point mutations can also cause complete deficiency in STS. Female carriers of STS do not show symptoms because of the gene's location on the X chromosome. De novo STS mutations can also occur. XLI is mainly differentiated from ichthyosis vulgaris and other types of ichthyosis, such as lamellar ichthyosis. Ichthyosis vulgaris is inherited in an autosomal dominant pattern, with symmetrical light grey scaling typically appearing after three months of age. Flexion zones are a

 Vaginal cancer is a rare gynecological malignancy, accounting for only 1-2% of all gynecologic neoplasms. Most cases (90%) are squamous cell carcinomas, while 5% are adenocarcinomas. Squamous cell carcinomas spread superficially, with the lungs and liver common sites of distant metastasis. Adenocarcinomas have a peak incidence between 17-21 years of age and tend to metastasize to the lung and supraclavicular or pelvic nodes. Clear-cell adenocarcinomas are the least common and are usually associated with adenosis. The human papillomavirus (HPV) is a known cause of vagina carcinoma, with subtypes HPV 16 and 18 being the primary types responsible. HPV infection can lead to the development of high-grade squamous intraepithelial lesions (HGSIL) and carcinoma of the vagina. The viral proteins E6 and E7 interfere with critical cell cycle points and contribute to HPV-related neoplasia. Diethylstilbestrol (DES) exposure in utero has also been linked to vaginal clear cell adenocarcinoma. Primar

 Polymyalgia rheumatica (PMR) is a prevalent inflammatory disorder of unknown origin that predominantly affects elderly individuals from Western countries. It is characterized by intense pain and stiffness involving the shoulders, proximal areas of the arms, neck, pelvic girdle, and proximal regions of the thighs. Patients with PMR commonly experience morning stiffness lasting more than 45 minutes and other non-specific symptoms like fatigue and malaise. Elevated acute phase reactants such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are typical in PMR. The disease affects women two to three times more often than men and is often linked with giant cell arteritis (GCA), the most frequent vasculitis in elderly people in Western countries, which mainly affects the large and medium arteries, particularly the branches of the proximal aorta. Patients with PMR are typically over 50 years old and present with bilateral pain and stiffness in the shoulders, proximal aspec

 Functional constipation (FC) is a condition that is diagnosed according to the Rome IV criteria. It involves the presence of two or more of the following symptoms: straining during at least 25% of defecations, lumpy or hard stools in at least 25% of defecations, the sensation of incomplete evacuation for at least 25% of defecations, the sensation of anorectal obstruction/blockage for at least 25% of defecations, manual manoeuvres to facilitate at least 25% of defecations, and fewer than three spontaneous bowel movements per week. Loose stools are rarely present in functional constipation without using laxatives, and the patient should not meet the criteria for irritable bowel syndrome. Functional constipation (FC) has three subtypes: normal transit constipation, slow transit constipation, and outlet constipation. Normal transit constipation occurs when there is a self-reported perception of constipation despite normal stool movement through the colon. Slow transit constipation occurs

 Dilated cardiomyopathy (DCM) is a pathological condition of the heart characterized by the dilation and enlargement of one or both ventricles, along with impaired contractility, as defined by a left ventricular ejection fraction (LVEF) of less than 40%. The condition can be classified as primary or secondary, with primary DCM being of idiopathic origin and diagnosed after excluding secondary causes. Patients with DCM typically have systolic dysfunction and may or may not exhibit overt symptoms of heart failure. DCM is often progressive, leading to heart failure and death. Without a transplant, survival rates for patients with DCM are poor. The etiology of DCM is diverse, with the most common cause being idiopathy, and may also have a familial or genetic predisposition. Secondary causes include infectious myocarditis, ischemic disease, hypertension, medication-induced alcohol abuse, HIV, peripartum cardiomyopathy, or infiltrative disease. The New York Heart Association (NYHA) classific

 Gout is a disorder of purine metabolism that causes hyperuricemia and generally refers to a form of arthritis. The first symptoms include intense pain in only one hallux joint in 90% of the cases. The elevated blood uric acid level in men (serum-urate level >7 mg/dl) and in women (serum-urate level >6) results in the formation of monosodium urate (MSU) crystals and deposition in joint bones and subcutaneous tissue. Hyperuricemia is not the only factor for gout. Other factors also implicated in gouts, such as age, gender, obesity, alcohol consumption, medication, comorbid disease, genetics, and purine diet. Hyperuricaemia and gout can be considered over four pathological stages development of hyperuricemia, deposition of monosodium urate crystals, the clinical presentation of gout flares due to an acute inflammatory response to deposited crystals, and clinical presentation of an advanced disease characterized by tophi. ·        The estimated prevalence of gout in U.S. adults is

 Scleroderma or Systemic sclerosis (SS), is a connective tissue disorder characterized primarily by the thickening and hardening of the skin. There are two primary types of scleroderma: localized and systemic. In localized scleroderma, the disease mainly affects the skin and may impact the muscles and bones. In systemic scleroderma, there is an involvement of the internal organs, such as the digestive tract, heart, lungs, and kidneys, among others. The severity and outcome of scleroderma are variable. Genetic and environmental factors play a role in the genesis of scleroderma. Silica and certain organic solvents are recognized as risk factors for the occurrence of systemic scleroderma. Life expectancy in patients with systemic sclerosis depends on the extent and severity of internal organ involvement. During SSc, the death rate is 3.5 times higher than healthy subjects of the same age. The overall survival of patients with SSc ranges from 75 to 80% after five years, 55% after ten years

Stomach cancer, also known as gastric cancer, is a malignancy that originates from the stomach lining. It is a slow-growing cancer and is considered a multifactorial disease. The International Agency for Research on Cancer (IARC) has classified the bacterium Helicobacter pylori (H. pylori) as a carcinogen in humans due to the evidence linking H. pylori infection and an increased risk of gastric cancer. The mechanism by which H. pylori acts as a carcinogen is believed to be indirect, through the induction of gastritis, which can lead to the development of precancerous conditions such as gastric atrophy, metaplasia, and dysplasia. Individuals with certain genetic disorders, such as hereditary diffuse gastric cancer, Peutz-Jeghers syndrome, and familial adenomatous polyposis, have an increased risk of developing stomach cancer. Mutations or deletions in genes such as p53, BRCA2, MSH2, and MLH1 also increase the risk of gastric cancer. The symptoms of stomach cancer can be classified into

Sezary Syndrome (SS) is a type of cutaneous T-cell lymphoma, a group of disorders characterized by transforming T-cells into cancerous cells and their effect on the skin. A small percentage of SS cases have been associated with human T-lymphotropic viruses type 1 and 2 (HTLV-I/II). Although the exact cause of SS is unknown, chromosomal anomalies, particularly rearrangements in the 6q23-27 region, leading to changes in the MYB proto-oncogene and the IL22RA2 gene, have been implicated. SS is more common in men and usually presents in the fifth decade of life. Patients typically experience rapid progression of symptoms, which include scaling erythroderma, leonine facies, severe pruritus, alopecia, ectropium, mild palmoplantar keratoderma, and nail onychodystrophy. Lymphadenopathy and hepatosplenomegaly may also be present, along with chills, fatigue, and general discomfort. Differential diagnoses for SS include mycosis fungoides, psoriasis, pityriasis rubra pilaris, dermatitis, hypereosin

 Semantic dementia (SD) is a type of frontotemporal dementia characterized by the progressive, amodal and profound loss of semantic knowledge (combination of visual, anomia, associative agnosia, surface dyslexia or dysgraphia and disrupted comprehension of word meaning) and behavioral abnormalities, attributable to the degeneration of the anterior temporal lobes. Typically presenting as a progressive, fluent anomic aphasia, SD is the paradigmatic disorder of semantic memory with a characteristic anatomical profile of asymmetric, selective anteroinferior temporal lobe atrophy. The earliest and most common symptom of SD is a reduction in expressive vocabulary, commonly referred to as a "loss of memory for words". Despite non-specific memory impairment, patients with SD typically exhibit relatively normal memory for recent day-to-day events and topographical aspects of memory, unlike early Alzheimer's disease. The differential diagnosis of SD includes other forms of Primary

 Primary Progressive Aphasia (PPA) is a neurodegenerative disorder primarily affecting language abilities. It is classified into three variants based on clinical characteristics, including logopenic variant PPA (lvPPA), nonfluent agrammatic PPA (nfaPPA), and semantic variant PPA (svPPA). The symptoms of PPA can vary and may include difficulty with speech, word finding, comprehension of language, and naming objects and people. PPA is a result of neurodegeneration, which refers to the progressive death of brain cells that cannot be attributed to other causes, such as head trauma, stroke, infection, or cancer. The three most commonly encountered underlying diseases causing PPA are frontotemporal lobar degeneration with abnormal TDP-43 accumulation (FTLD-TDP-43), frontotemporal lobar degeneration with abnormal tau protein accumulation (FTLD-tau), and Alzheimer's disease (AD). When abnormal proteins associated with Alzheimer's disease or one of the forms of frontotemporal lobar dege

 Wilms' Tumor or Nephroblastoma is a rare malignant renal tumor that typically affects children, characterized by abnormal proliferation of cells that resemble embryonic kidney cells (metanephroma), leading to the term embryonal tumor. It mainly affects young children between the ages of 1 and 5 years, although it can occur before the age of 1 year or after the age of 8 years. Adult forms are very rare. The tumor is usually present as an abdominal mass, which is frequently unilateral. Other symptoms may include abdominal pain, hypertension, fever, hematuria, and anemia. The disease progresses rapidly, with regional dissemination in the retroperitoneal space, lymph nodes, vessels (renal vein and inferior vena cava), and the peritoneal cavity in cases of tumor effraction, with a high likelihood of metastases in the lungs and liver. Nephroblastoma is sporadic in 99% of cases, with 10% of these cases associated with congenital anomalies or specific syndromes. Genetic anomalies have bee

 Mastocytosis is a disorder resulting from the increased proliferation of mast cells involved in the immune system. The disease can manifest cutaneously (involving the skin) and systemically (affecting multiple body systems). The skin is the most commonly affected area and can present with various cutaneous manifestations, including urticaria pigmentosa, diffuse cutaneous mastocytosis, mastocytoma, and telangiectasia macularis eruptiva perstans. Clinical symptoms include flushing, itching, abdominal pain, diarrhea, hypotension, fainting, and musculoskeletal pain, caused by the release and infiltration of mast cell mediators into various organs such as the skin, gastrointestinal tract, liver, spleen, lymph nodes, and bone marrow. It has been classified into seven categories according to the World Health Organization (WHO) consensus: cutaneous mastocytosis, indolent systemic mastocytosis, systemic mastocytosis with associated clonal hematological non–mast cell lineage disease, aggressive

 Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are aggressive soft tissue tumors that primarily originate from the peripheral nerves. They demonstrate variable differentiation towards the cellular components of the nerve sheath, such as Schwann cells, fibroblasts, or perineurial cells. MPNSTs are common in adults with no gender bias but tend to occur at a younger mean age in patients with neurofibromatosis type 1 (NF1). The tumors are most frequently found in the extremities, particularly proximally, followed by the trunk, head, and neck. The sciatic nerve is the most commonly involved major nerve trunk. Clinical presentation includes a painful or rapidly growing mass and associated neurologic deficits. Approximately half of the MPNSTs arise in the context of NF1 syndrome, often associated with pre-existing plexiform neurofibromas. The lifetime risk of developing MPNST in NF1 patients is 8-13%. An important symptom is developing new, worsening, or persistent pain in a neurofibroma

 Hypereosinophilic Syndrome (HES) is a group of disorders characterized by elevated blood eosinophil counts (>1.5 × 109/L) and resultant organ damage, commonly affecting the heart. Initially, the term referred to the combination of peripheral blood eosinophilia and tissue infiltrates leading to dysfunction or damage. The "idiopathic" label reflected the lack of knowledge regarding underlying causes, excluding known diseases such as drug allergies, parasitic infections, cancer, lymphoma and myeloproliferative disorders. Symptoms of HES can vary greatly among patients and include skin rashes, dizziness, memory loss, coughing, shortness of breath, fatigue, fever, and mouth sores. Organ damage or dysfunction occurs due to the release of cytotoxic substances by eosinophils, including eosinophil cationic protein, major basic protein, ribonuclease eosinophil derived neurotoxin, eosinophil peroxidase, and enzymes such as elastase and collagenase. Eosinophils also secrete cytokines

 Germ cell tumors (GCTs) are a heterogeneous group of neoplasms that derive from primordial germ cells and are commonly found in the gonads, but can also occur in the anterior mediastinum, pineal gland, and brain. GCTs can be classified into two major categories, Seminomas and non-seminomas, which have different clinical implications and prognoses. Seminomas generally have a better outcome, while non-seminomatous tumors are more likely to present with metastatic disease or mixed germ cell components. The precise etiology of extragonadal germ cell tumors (EGGCTs) remains controversial, with two theories proposed to explain their origin: aberrant migration of primordial germ cells during embryonic development or reverse migration from the gonads. Intracranial germ cell tumors, including germinoma, have distinct biological properties compared to neuroepithelial tumors, with activating mutations in the c-KIT receptor tyrosine kinase pathway and downstream regulators frequently seen in germ

Epithelial ovarian cancer is a neoplastic disease that originates from the epithelial cells that line the ovary and fallopian tubes. It is the most commonly diagnosed histological subtype of ovarian cancer, with a median age of onset between 60 and 65 years. Women under the age of 30 are rarely diagnosed with epithelial ovarian cancer, with the majority of malignancies in this age group being germ cell tumors. Symptoms of epithelial ovarian cancer are often nonspecific and include abdominal bloating, early satiety, nausea, abdominal distension, change in bowel function, urinary symptoms, back pain, fatigue, and weight loss. These symptoms typically present months before diagnosis and are more common in the advanced stages of the disease. Ovarian epithelial cancer is divided into two groups, type I and type II. Type I tumors are slow-growing and often found at an early stage, while type II tumors are fast-growing and usually found at an advanced stage. Type I tumors include low-grade se

 Diphtheria is a bacterial infection caused by Corynebacterium species, primarily Corynebacterium diphtheria, and is characterized by the production and systemic distribution of exotoxin. Exotoxin, a single polypeptide composed of subunits A and B, interferes with protein synthesis through ADP-ribosylation of elongation factor 2. The clinical manifestations of diphtheria vary depending on the anatomic site of infection, the immune status of the host, and exotoxin production. Corynebacterium diphtheria is a non-encapsulated, non-motile, gram-positive bacillus that forms club-shaped structures arranged in palisade formations. The primary host response to C. diphtheria results in the formation of a gray pseudomembrane in the throat and pharynx, a characteristic physical finding of the disease. Other Corynebacterium species, such as Corynebacterium ulcerans, can cause diphtheria. Diphtheria should be differentiated from other infections with similar presentations, including epiglottitis, r