Scrotal Skin Diseases: Causes, Symptoms, Diagnosis, and Treatment

Scrotal Skin Diseases: Causes, Symptoms, Diagnosis, and Treatment

pediagenosis    October 15, 2026   

SCROTAL SKIN DISEASES I: CHEMICAL AND INFECTIOUS

Many skin diseases of infectious, allergic, or metabolic origin can involve the scrotum. Among many yeasts, molds, and fungi, only a few are infectious and are termed dermatophytes (“skin fungi”). Skin fungi live only on the dead layer of keratin protein on the skin surface. They rarely invade deeper and cannot live on mucous membranes. Infections by the fungus tinea cruris (ring-worm) are very common in the groin and scrotum. It involves desquamation of the scrotal skin and contiguous surfaces of the inner thighs and itches (“jock itch”). Tinea begins with fused, superficial, reddish-brown, well-defined scaly patches, which extend and coalesce into large, symmetrical, inflamed areas. The margins of the lesions are characteristically distinct. The initial lesion may become macerated and infected and is painful and itches. Sweating, tight clothing or obesity favor development and recurrence of this fungal infection, derived mainly from the genera Trichophyton and Microsporum. These same organisms cause tinea pedis or “athlete’s foot.”

Direct and Indirect Inguinal Hernias : Causes, Symptoms & Treatment

Direct and Indirect Inguinal Hernias : Causes, Symptoms & Treatment

pediagenosis    October 15, 2026    Comment   

INDIRECT AND DIRECT INGUINAL HERNIAS

Hernia (a word derived from the Greek, meaning “sprouting forth”) has been defined, from the time of A. Cornelius Celsus (second century AD), as a protrusion of an organ or tissue, through an abnormal opening, from the organ’s natural place in a cavity. Hernias are classified by the cause or the anatomic location of the defect.

Basal Cell Nevus Syndrome (Gorlin Syndrome): Symptoms & Treatment

Basal Cell Nevus Syndrome (Gorlin Syndrome): Symptoms & Treatment

pediagenosis    October 14, 2026    Comment   

MANIFESTATIONS OF BASAL CELL NEVUS SYNDROME

BASAL CELL NEVUS SYNDROME

Basal cell nevus syndrome (BCNS), also known as nevoid basal cell carcinoma syndrome or Gorlin syndrome, is an uncommon autosomal dominant genodermatosis caused by mutations in the patched-1 (PTCH1) gene on chromosome 9. Approximately 40% of cases represent new, spontaneous mutations. Affected individuals are predisposed to the development of multiple basal cell carcinomas (BCCs), often in the hundreds over their lifetime. The diagnosis of this syndrome is based on a number of established criteria.

Chagas Disease: Causes, Symptoms, Heart Damage & Complications

Chagas Disease: Causes, Symptoms, Heart Damage & Complications

pediagenosis    October 14, 2026    Comment   

CHAGAS DISEASE (TRYPANOSOMIASIS)

Chagas Disease

Chagas disease, also called South American (or American) trypanosomiasis, is a menace to millions of people in South-Central America. The parasite Trypanosoma cruzi enters the body, usually through the bite of a reduviid (assassin or kissing bug), or by the transfusion or inoculation of contaminated blood. The parasite circulates only in its trypanosomal form. It enters a body cell, transforms to a leishmania, and multiplies to form a leishmanial cyst, which ruptures the invaded cell. In this stage the parasites are released and transformed into trypanosomes, which circulate in the blood and invade other cells, thus continuing the cycle. The cardiac muscle cells are targeted in most cases, but with some strains in particular areas, there is equal or greater proclivity for the peripheral ganglion cells to be invaded or destroyed. In the rarer acute cases, all cells and tissues may be invaded, but in chronic cases, major damage is to the cardiac muscle cells and peripheral ganglion cells (see Plate 6-147).

Small Intestinal Bleeding: Causes, Symptoms, Diagnosis & Treatment

Small Intestinal Bleeding: Causes, Symptoms, Diagnosis & Treatment

pediagenosis    October 13, 2026    Comment   

VASCULAR MALFORMATION OF SMALL INTESTINE AND OTHER CAUSES OF SMALL INTESTINAL BLEEDING

Approximately 5% of cases of gastrointestinal bleeding occur in the small bowel, defined as the region between the ampulla of Vater and the ileocecal valve. Small intestinal vascular malformations are responsible for the majority of cases of small intestinal bleeding. They are more often seen in elderly patients, as is enteropathy induced by nonsteroidal antiinflammatory drugs (NSAIDs). Small intestinal tumors, Crohn disease, and nonspecific enteritis are more common in individuals under 40 years of age. Rarer causes include Meckel diverticulum, hemobilia, hemosuccus pancreaticus, and aortoenteric fistula.

Normal-Pressure Hydrocephalus: Symptoms, Causes, Diagnosis & Treatment

Normal-Pressure Hydrocephalus: Symptoms, Causes, Diagnosis & Treatment

pediagenosis    October 12, 2026    Comment   

NORMAL-PRESSURE HYDROCEPHALUS

The “plumbing system” of the central nervous system (CNS) operates in a delicate balance. Fluid produced in the choroid plexus of the lateral ventricles circulates through the third ventricle, cerebral aqueduct (of Sylvius), and fourth ventricle. After exiting from the roof of the fourth ventricle, the cerebrospinal fluid (CSF) circulates around the brain within the subarachnoid cisterns, and is ultimately absorbed by the arachnoid granulations into the circulation. If more CSF is produced than is absorbed, the ventricles and subarachnoid space distend with fluid. In the adult, this imbalance leads to enlargement of the ventricles, which then encroach on the normal cerebral white matter, especially frontally.

Amebic Pericarditis: Causes, Symptoms, Diagnosis & Treatment

Amebic Pericarditis: Causes, Symptoms, Diagnosis & Treatment

pediagenosis    October 11, 2026    Comment   

Amebic Pericarditis

Amebiasis

Amebiasis, transmitted by the protozoan Entamoeba histolytica, is considered initially and predominantly an intestinal disease, but it involves the liver in a substantial proportion of patients. The infective encysted form of the parasite, communicated person to person without an intermediate host and usually by water or food contaminated by human fecal material, enters the intestinal tract by the mouth, passes through the stomach, and loses its cystic wall in the small intestine. There the cyst, 5 to 20 µ in diameter, having matured during its passage, releases from one to four trophozoites (vegetative form), which in contrast to the cyst, are mobile but do not survive outside the host’s body. The amebas, which have attached themselves to the colonic wall, migrate into the crypts and penetrate the epithelium and muscularis. From the submucosa, the amebas move along to other organs, particularly the liver, creating there the chronic nonsuppurative form of amebic hepatitis or producing abscesses. Other trophozoites are excreted in the encysted form, thus maintaining the life cycle.

Medial Surface of the Lungs: Anatomy, Hilum and Impressions

Medial Surface of the Lungs: Anatomy, Hilum and Impressions

pediagenosis    October 09, 2026    Comment   

Medial Surface Of The Lungs

The medial (mediastinal) surfaces of the right and left lungs present concave mirror images of the right and left sides of the mediastinum so that in addition to the structures forming the root of the lung, the medial lung surface presents distinct impressions made by the structures constituting the mediastinum (see Plates 1-18 and 1-19).

Congenital Uterine Anomalies: Types, Causes and Anatomy

Congenital Uterine Anomalies: Types, Causes and Anatomy

pediagenosis    October 09, 2026    Comment   

CONGENITAL ANOMALIES

The female genital tract develops from paired embryologic structures, the müllerian ducts, which give rise to the tubes and uterus as well as the upper two-thirds of the vagina. The upper or cephalic portion of the müllerian ducts, shortly after having made its appearance during the second month of fetal life, develops and courses longitudinally, parallel and lateral to the wolffian (mesonephric) ducts. In the caudal region of the mesonephros, the müllerian ducts approach the midline, taking an oblique route for a short distance while crossing the wolffian ducts, then turn again, assuming a longitudinal direction now medial to the wolffian ducts. In this proximal part, the right and the left müllerian ducts approach each other and finally fuse to form the uterovaginal canal. The cephalic, originally longitudinal, part of the ducts are transformed and differentiate into the fallopian tubes. The short part, in the region where the wolffian duct is crossed in the early stages, gives rise to the uterine fundus and the uterine–tubal junction, whereas the uterine cervix and the vagina take their origin from the lower longitudinal portion of the müllerian ducts. The uterine corpus develops from a very small part of the müllerian ducts, a fact that explains the ratio of cervical length to the length of the entire uterus during fetal life and long after, until the ovarian hormones display their effect on the responsive tissue of the uterine body.

Pharynx

Pharynx

pediagenosis    October 07, 2026   

Pharynx

The pharynx is a musculomembranous tube; much of its anterior wall is absent due to the fact that the right and left nasal cavities, oral cavity, and larynx open into its anterior side. It extends from the base of the skull to the inferior border of the cricoid cartilage at the level of the lower margin of the sixth cervical vertebra, at which time it becomes continuous with the esophagus. In addition to the cavities already listed, the pharynx also communicates with the middle ear on each side by means of the auditory (eustachian) tube; this fact explains how infections spread from the pharynx to the middle ear, making a total of seven cavities with which it has communication. The transverse diameter of the pharynx exceeds the anteroposterior diameter, which is greatest superiorly and is diminished to nothing inferiorly where the anterior and posterior walls are in contact unless separated during the act of swallowing. The transverse diameter does not differ greatly throughout the length of the pharynx, except where it narrows at the lower end.