Crohn’s Disease

Crohn’s disease is a condition that affects different parts of the digestive tract. The location of the disease can be classified as ileal, colonic, ileo-colonic, or upper gastrointestinal tract. In some cases, the disease can cause a solid, thickened mass around the caecum, which also involves the terminal ileum. This is known as ileo-colonic Crohn’s disease.

While weight loss is a common symptom of Crohn’s disease, it is not always present. It is important to note that the range of areas affected by the disease makes it unlikely for it to be classified as anything other than ileo-colonic Crohn’s disease.

Differential Diagnosis for a Patient with Iron Overload

A middle-aged man presents with skin discoloration, chronic liver disease, arthralgia, and erectile dysfunction. His serum ferritin level is significantly elevated at 623, indicating iron overload. However, liver disease can also cause an increase in serum ferritin.

Acute viral hepatitis is unlikely as his symptoms have been worsening over the past 6-9 months, and his transaminase levels are only moderately elevated. Alcoholic cirrhosis is also unlikely as his alcohol intake is modest.

Excess iron ingestion is a possibility, but it would require significant ingestion over a long period of time. Wilson’s disease, a recessively inherited disorder of copper metabolism, is also unlikely as it does not explain the symptoms of iron overload.

Overall, the differential diagnosis for this patient includes haemochromatosis, a genetic disorder that causes iron overload. Further testing and evaluation are necessary to confirm the diagnosis and determine the appropriate treatment plan.

Blood Supply to the Digestive System: Arteries and their Branches

The digestive system receives its blood supply from several arteries and their branches. The coeliac trunk, which originates from the abdominal aorta, carries the major blood supply to the stomach through its three main divisions: the left gastric artery, the common hepatic artery, and the splenic artery. The inferior mesenteric artery supplies the colon and small bowel, while the superior mesenteric artery mainly supplies the duodenum, small intestines, colon, and pancreas. The splenic artery supplies blood to the spleen and gives rise to the left gastroepiploic artery. The artery of Drummond connects the inferior and superior mesenteric arteries and is also known as the marginal artery of the colon. It is important to note that the absence of this artery is a variant and not pathological.

The Origin of Hepatocytes: Understanding the Different Germ Layers

Hepatocytes are a type of cell found in the liver that play a crucial role in metabolism and detoxification. Understanding their origin can provide insight into various liver diseases and conditions.

Endoderm is the germ layer from which hepatocytes differentiate during embryonic development. Mallory bodies, intracytoplasmic inclusions seen in injured hepatocytes, are derived from cytokeratin, an intermediate cytoskeletal filament unique to epithelial cells of ectodermal or endodermal origin.

While hepatocytes and bile ducts are endodermal in origin, hepatic blood vessels and Kupffer cells (hepatic macrophages) are mesodermal in origin.

Spider angioma, palmar erythema, gynaecomastia, and dilation of the superficial abdominal veins are signs of cirrhosis or irreversible liver injury. Bridging fibrosis extending between the adjacent portal systems in the liver is the precursor of cirrhosis.

It is important to note that hepatocytes are not derived from ectoderm or neural crest cells. The yolk sac gives rise to primordial germ cells that migrate to the developing gonads.

Understanding the origin of hepatocytes and their relationship to different germ layers can aid in the diagnosis and treatment of liver diseases.

Possible Causes of Obstructive Jaundice: A Case Analysis

The patient’s symptoms suggest that the most probable cause of obstructive jaundice is gallstones lodged in the common bile duct. Recurrent episodes of biliary colic and/or cholecystitis may have caused the intermittent abdominal pain, which has now worsened and led to hepatic obstruction. Cholecystitis, inflammation of the gallbladder due to gallstones, would not cause obstructive jaundice unless the gallstones leave the gallbladder and become lodged in the common bile duct. Alcohol-induced pancreatitis is a common cause of acute pancreatitis in the UK, but it will not cause obstructive jaundice. Hepatitis C may cause cirrhosis and subsequently jaundice, but there is no evidence that the patient is an intravenous drug user. Pancreatic carcinoma, particularly if located in the head of the pancreas, can cause obstructive jaundice, but it is usually painless in origin. Courvoisier’s law states that a non-tender palpable gallbladder accompanied by painless jaundice is unlikely to be caused by gallstones.

Understanding Meckel’s Diverticulum: A Congenital Abnormality of the Gastrointestinal Tract

Meckel’s diverticulum is a common congenital abnormality of the gastrointestinal tract that affects around 2-4% of the population. It is an anatomical remnant of the vitello-intestinal duct, which connects the primitive midgut to the yolk sac during fetal development. Meckel’s diverticulum can contain various types of tissue, including gastric mucosa, liver tissue, carcinoid, or lymphoid tissue. It is usually located around 2 feet from the ileocaecal valve and is commonly found adjacent to the vermiform appendix.

Symptoms of Meckel’s diverticulum can closely mimic appendicitis, and it can be a cause of bowel obstruction, perforation, and gastrointestinal bleeding. Bleeding is the most common cause of clinical presentations, and the presence of gastric mucosa is important as it can ulcerate and cause bleeding. If a normal-looking appendix is found during laparoscopy, it is important to exclude Meckel’s diverticulum as a potential cause of the patient’s symptoms. The mortality rate in untreated cases is estimated to be 2.5-15%.

Advances in imaging have made it easier to detect Meckel’s diverticulum. It can be picked up on barium imaging, computed tomography enterography, and radionuclide technetium scanning (Meckel’s scan). Selective mesenteric arteriography may also be useful in patients with negative imaging results.

In conclusion, understanding Meckel’s diverticulum is important for clinicians as it is a common congenital abnormality that can cause significant morbidity and mortality if left untreated.

When differentiating between ulcerative colitis and Crohn’s disease, it is important to note that crypt abscesses are typical for ulcerative colitis, while other options are more commonly found in Crohn’s disease. Ulcerative colitis is the most common form of inflammatory bowel disease, with inflammation starting in the rectum and spreading upwards in a contiguous fashion. Patients typically experience left-sided abdominal pain, cramping, bloody diarrhea with mucous, and unintentional weight loss. Extra-intestinal manifestations may include seronegative arthropathy and pyoderma gangrenosum. Barium enema and colonoscopy are used to diagnose ulcerative colitis, with the latter revealing diffuse and contiguous ulceration and inflammatory infiltrates affecting the mucosa and submucosa only. Complications of long-term ulcerative colitis include large bowel adenocarcinoma, toxic megacolon, and primary sclerosing cholangitis. In contrast, Crohn’s disease usually presents with right-sided abdominal pain, watery diarrhea, and weight loss. Barium enema and colonoscopy reveal multiple ulcers and bowel wall thickening, with the microscopic appearance showing a mixed acute and chronic transmural inflammatory infiltrate with non-caseating granulomas. Terminal ileum involvement is typical for Crohn’s disease, while stricturing and fistula formation are common complications due to its transmural inflammatory nature. Overall, while both ulcerative colitis and Crohn’s disease are systemic illnesses, they have distinct differences in their clinical presentation and diagnostic features.

Treatment Options for Autoimmune Hepatitis: Azathioprine and Prednisolone

Autoimmune hepatitis (AIH) is a chronic liver disease that primarily affects young and middle-aged women. The cause of AIH is unknown, but it is often associated with other autoimmune diseases. The condition is characterized by inflammation of the liver, which can progress to cirrhosis if left untreated.

The first-line treatment for AIH is a combination of azathioprine and prednisolone. Patients with moderate-to-severe inflammation should receive immunosuppressive treatment, while those with mild disease may be closely monitored instead. Cholestyramine, a medication used for hyperlipidemia and other conditions, is not a first-line treatment for AIH.

Liver transplantation is not typically recommended as a first-line treatment for AIH, but it may be necessary in severe cases. However, AIH can recur following transplantation. Antiviral medications like peginterferon alpha-2a and tenofovir are not effective in treating AIH, as the condition is not caused by a virus.

In summary, azathioprine and prednisolone are the primary treatment options for AIH, with liver transplantation reserved for severe cases. Other medications like cholestyramine, peginterferon alpha-2a, and tenofovir are not effective in treating AIH.

Comparison of Different Medical Conditions

Pellagra: A Serious Condition Caused by Niacin Deficiency

Pellagra is a severe medical condition that can lead to death if left untreated. It is characterized by three classical features, including diarrhoea, dermatitis, and dementia. The condition is caused by a deficiency of niacin, which is required for all cellular processes in the body. Pellagra can also develop due to a deficiency of tryptophan, which can be converted to niacin. Treatment for pellagra involves vitamin replacement with nicotinamide.

Scurvy: Bleeding Gums and Muscle Pains

Scurvy is a medical condition that can cause red dots on the skin, but it typically presents with bleeding gums and muscle pains. The condition is caused by a deficiency of vitamin C, which is required for the synthesis of collagen in the body. Treatment for scurvy involves vitamin C replacement.

Post-Infective Lactose Intolerance: Bloating and Abdominal Discomfort

Post-infective lactose intolerance is a medical condition that typically presents after gastrointestinal infections. It can cause bloating, belching, and abdominal discomfort, as well as loose stool. However, the history of skin changes and forgetfulness would point more towards pellagra.

Depression: Not Related to Skin Changes or Diarrhoea/Vomiting

Depression is a medical condition that can cause a range of symptoms, including low mood, loss of interest, and fatigue. However, it is not related to skin changes or diarrhoea/vomiting.

Systemic Lupus Erythematosus (SLE): Painful Swollen Joints and Red ‘Butterfly’ Rash

SLE is a medical condition that typically presents with painful swollen joints and a red ‘butterfly’ rash over the face. Other common symptoms include fever, mouth ulcers, and fatigue.

Management of Suspected Oesophageal Rupture

Suspected oesophageal rupture is a medical emergency that requires urgent intervention. This condition is more common in patients with a history of alcohol excess and can be associated with a triad of vomiting, chest pain, and subcutaneous emphysema. Symptoms include retrosternal chest/epigastric pain, tachypnoea, fever, pain on swallowing, and shock. A chest X-ray reveals gas within soft tissue spaces, pneumomediastinum, left pleural effusion, and left-sided pneumothorax. Without rapid treatment, the condition can be fatal.

Antibiotics are necessary to treat the infection that may result from oesophageal rupture. However, they will not address the underlying cause of the infection.

Chest drain insertion is not the correct management for pneumothorax secondary to oesophageal rupture. A chest drain would not resolve the underlying cause, and air would continue to enter the pleural cavity via the oesophagus.

Proton pump inhibitors (PPIs) are not appropriate for suspected oesophageal rupture. PPIs would be the correct management for a suspected perforated ulcer. However, the history of acute-onset pain following vomiting is more in keeping with oesophageal rupture.

Urgent endoscopy is not appropriate for suspected oesophageal rupture. Endoscopy risks further oesophageal perforation, and there is no report of haematemesis or melaena, making this a less likely cause of the patient’s symptoms.

Management of Suspected Oesophageal Rupture: Antibiotics, Chest Drain Insertion, PPIs, and Endoscopy