Medicine

Explanation: Hypothermia exists when the body’s normal thermal regulatory mechanisms are unable to maintain heat in a cold environment and core temperature falls below 35°C

Explanation: CT is is the first line investigation of stroke

Hyperkalaemia is a life-threatening complication of AKI due to impaired potassium excretion.

Reference: Davidson 23rd; P-800

Stem Breakdown:

Chronic diarrhoea, weight loss, and iron deficiency anaemia: These symptoms are indicative of malabsorption, which is a hallmark of coeliac disease.
Pruritic, blistering rash on elbows and knees: This describes dermatitis herpetiformis, a skin manifestation of coeliac disease.
Option Analysis:

A) Coeliac disease: This is the correct diagnosis. Davidson and Harrison explain that coeliac disease is an autoimmune disorder triggered by gluten ingestion, leading to small intestinal damage and malabsorption. Chronic diarrhoea, weight loss, and iron deficiency anaemia are common presentations. Dermatitis herpetiformis, a pruritic vesicular rash, is pathognomonic for coeliac disease.
B) Crohn’s disease: Crohn's disease can cause chronic diarrhoea and weight loss, but it typically presents with other features such as abdominal pain, perianal disease, or fistulas. Additionally, dermatitis herpetiformis is not associated with Crohn’s disease.
C) Ulcerative colitis: Ulcerative colitis primarily affects the colon, causing bloody diarrhoea and abdominal pain. It does not cause malabsorption or dermatitis herpetiformis.
D) Irritable bowel syndrome (IBS): IBS is a functional gastrointestinal disorder characterised by abdominal pain and altered bowel habits, but it does not cause malabsorption, weight loss, or iron deficiency anaemia.

GI bleeding (e.g., ulcers, colon cancer) or menstrual loss are primary causes.

Reference: Davidson 23rd, Page: 644, Box : 18.14

2 equations
1.Hendersson  Hasslebach equation
2.Anion  Gap

Explanation: ‘comedone’ is a Hallmark of Acne

Weight loss with low grade evening fever, cough and night sweats indicates tuberculosis.
Weight loss in spite of good appetite or high food intake—thyrotoxicosis, diabetes mellitus, malabsorption syndrome.
Weight loss with pigmentation and hypotension—Addison’s disease.

Infection is cardinal symptom of immunodeficiency

Stem Breakdown:

Exertional dyspnoea, chest pain, and syncope: These are classic symptoms of aortic stenosis, indicating reduced cardiac output due to a narrowed aortic valve.
Harsh systolic murmur at the right upper sternal border, radiating to the carotids: This is the hallmark murmur of aortic stenosis, which is best heard at the aortic valve area and radiates to the carotids.
Option Analysis:

A) Aortic stenosis: This is the correct diagnosis. Davidson and Harrison explain that aortic stenosis is a common ventricular heart disease, particularly in older adults. It presents with exertional symptoms due to restricted blood flow through the stenotic aortic valve. The characteristic, harsh systolic murmur radiating to the carotids is diagnostic.
B) Mitral regurgitation: Mitral regurgitation causes a holosystolic murmur best heard at the apex and radiating to the axilla. It is associated with symptoms of heart failure but does not present with aortic murmur characteristics.
C) Aortic regurgitation: Aortic regurgitation causes a diastolic murmur best heard at the left sternal border. It is associated with wide pulse pressure and a "water hammer" pulse, but the systolic murmur described here points to aortic stenosis.
D) Hypertrophic cardiomyopathy: Hypertrophic cardiomyopathy causes a systolic murmur, but it is typically best heard at the left sternal border and increases with manoeuvres like Valsalva. It is associated with a thickened interventricular septum, leading to outflow obstruction.

Reference: Davidson 23rd; P-862
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Ref: Davidson 23rd; P-949 (Box-23.38)

During episodes of AF, the atria beat rapidly but in an uncoordinated and ineffective manner. The ventricles are activated irregularly at a rate determined by conduction through the AV node. This produces the characteristic ‘irregularly irregular’ pulse. The ECG shows normal but irregular QRS complexes; there are no P waves.

Reference: Davidson 23rd; P-795
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Stem Breakdown:

Episodic dizziness, tinnitus, and hearing loss: This triad of symptoms is classic for Meniere’s disease, a disorder of the inner ear.
Left ear involvement: Meniere’s disease often affects one ear initially.
Option Analysis:

A) Benign paroxysmal positional vertigo (BPPV): BPPV causes brief episodes of vertigo triggered by head movements, but it is not associated with hearing loss or tinnitus.
B) Meniere’s disease: This is the correct diagnosis. Davidson and Harrison explain that Meniere’s disease is caused by abnormal fluid accumulation in the inner ear, leading to episodes of vertigo, tinnitus, and fluctuating hearing loss. It is typically unilateral, affecting one ear initially.
C) Vestibular neuritis: Vestibular neuritis causes acute vertigo due to inflammation of the vestibular nerve, but it does not cause hearing loss or tinnitus.
D) Acoustic neuroma: Acoustic neuroma (vestibular schwannoma) can cause unilateral hearing loss and tinnitus, but it typically presents with gradual onset rather than episodic symptoms. Vertigo is less common.

Prick tests are used to investigate cutaneous type I (immediate) hypersensitivity to various antigens such as pollen, house dust mite or dander.

Reference: Davidson 23rd; P-518

Gastric aspiration and/or lavage is very infrequently indicated in acute poisoning, as it is no more effective than activated charcoal for most substances and complications are common, especially pulmonary aspiration. It is contraindicated if strong acids, alkalis or petroleum distillates have been ingested

For the diagnosis of primary pulmonary tuberculosis in children, who often do not expectorate sputum, specimens from early-morning gastric lavage may yield positive cultures.

Severe epigastric pain radiating to the back is classic for pancreatitis, often accompanied by vomiting and elevated serum amylase/lipase

Phalen’s test (wrist flexion for 60 seconds to reproduce paresthesia in the median nerve distribution) as highly specific for carpal tunnel syndrome. Tinel’s sign (a) (tapping over the median nerve causing tingling) is less specific, Froment’s sign (c) is used for ulnar nerve dysfunction, and Finkelstein’s test (d) is specific for de Quervain’s tenosynovitis.

Davidson 23rd; P-1102

Explanation: The most common cause of Chronic or relapsing diarrhea is irritable bowel syndrome

Variations in red cell size is called anisocytosis.

NS1 antigen is detectable in the first 5 days of infection, confirming acute dengue

Explanation: Alcoholic liver disease is the leading cause of cirrhosis in the Western world. Davidson describes that chronic alcohol consumption leads to progressive liver inflammation, fibrosis, and eventually cirrhosis. Harrison explains that while viral hepatitis and non-alcoholic fatty liver disease are rising causes of cirrhosis, alcohol remains the most common etiology in developed countries due to its widespread consumption.

Reference: Practical Manual in Clinical Medicine by Professor ABM Abdullah; P-164

Thromboembolism is a significant complication of nephrotic syndrome, largely due to the urinary loss of anticoagulant proteins, particularly antithrombin III, increasing the risk of clots.

Penicillin remains first-line for all stages; alternatives (e.g., doxycycline) are used only if penicillin-allergic

Reference: Davidson 23rd; P-781

Tools
CBC
Sputum smear examination
Radiological (X-ray) examination of the lungs
Culture of TB bacilli
Rapid Molecular Diagnostic Tests (RMDT)
Gene Xpert
Line Probe Assay (LPA)
FNAC, Biopsy and Histopathology for EP TB
IGRA

Anti-HBs indicates recovery and immunity. HBsAg indicates current infection, and anti-HBc IgM suggests acute infection.

Reference: Davidson 23rd, Box-11.55

Explanation: Four chamber. Right & left atrium. Right & left ventricle

Lymph node TB (e.g., cervical lymphadenitis or scrofula) is the most common form of extrapulmonary TB, especially in high-prevalence areas. It presents as painless, enlarged lymph nodes. Other sites like bones, meninges, and kidneys are less common

Reference: Davidson 23rd; P-609

The diagnosis can often be made on the basis of clinical features and the ECG; the latter shows ST elevation with upward concavity over the affected area, which may be widespread. PR interval depression is a very specific indicator of acute pericarditis.

Explanation: The temporal lobes contain the primary auditory cortex and primary vestibular cortex

Reference: Davidson 23rd; P-853
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Reference: Davidson 23rd; P-565

Reference: Davidson 23rd; P-816

Stem Breakdown:

Fatigue, weight loss, and night sweats: These are "B symptoms," often seen in lymphomas.
Enlarged, non-tender lymph nodes in the cervical and axillary regions: Painless lymphadenopathy is a common presenting sign of lymphoma.
Option Analysis:

A) Hodgkin lymphoma: Hodgkin lymphoma typically presents with painless lymphadenopathy and "B symptoms," but it is more likely to involve mediastinal lymph nodes rather than widespread cervical and axillary nodes. The presence of Reed-Sternberg cells on biopsy confirms the diagnosis, but the stem lacks specific findings for Hodgkin lymphoma.
B) Non-Hodgkin lymphoma: This is the correct diagnosis. Davidson and Harrison explain that non-Hodgkin lymphoma (NHL) often presents with painless, generalized lymphadenopathy and systemic symptoms like weight loss and night sweats. NHL is more likely than Hodgkin lymphoma to cause widespread lymph node involvement.
C) Chronic lymphocytic leukemia (CLL): CLL causes painless lymphadenopathy and systemic symptoms, but it is also associated with an elevated white blood cell count (lymphocytosis), which is not mentioned in the case.
D) Tuberculosis: Tuberculosis can cause lymphadenopathy, particularly in the cervical region (scrofula), and systemic symptoms, but it typically presents with caseating granulomas on biopsy, and pulmonary involvement is common.

Type I RTA is characterized by:

•Impaired hydrogen ion secretion in Distal  tubule
•Hypokalemia
•Hypocitraturia
•Hypercalciuria
•Nephrocalcinosis
•Renal Stones

Explanation: Osteophyte formation is characteristic of osteoarthritis, not rheumatoid arthritis. Davidson describes rheumatoid arthritis (RA) as a chronic autoimmune disease with symmetrical joint involvement, morning stiffness, and joint erosions visible on imaging. Harrison adds that RA is associated with systemic inflammation and can lead to joint deformity if untreated.

Explanation: There are 64 different codons with some redundancy in the system: 61 codons encode one of the 20 amino acids, and the remaining three codons – UAA, UAG and UGA (known as stop codons) – cause termination of the growing polypeptide chain.

Stem Breakdown:

Abdominal pain, bloody diarrhoea, and tenesmus: These are classic symptoms of ulcerative colitis (UC), which is an inflammatory bowel disease affecting the colon.
Continuous inflammation from the rectum to the sigmoid colon: UC is characterised by continuous inflammation starting in the rectum and extending proximally, often limited to the colon.
Option Analysis:

A) Ulcerative colitis: This is the correct diagnosis. Davidson and Harrison describe ulcerative colitis as a chronic inflammatory condition of the colon characterised by continuous inflammation, starting at the rectum and extending proximally. Bloody diarrhoea, abdominal pain, and tenses are hallmark symptoms. UC is often limited to the mucosa and submucosa of the colon, distinguishing it from Crohn's disease.
B) Crohn’s disease: Crohn's disease can affect any part of the gastrointestinal tract and is characterised by "skip lesions" (areas of normal bowel between inflamed segments). It also often involves transmural (full-thickness) inflammation, which can lead to complications like fistulas and strictures. The continuous inflammation seen in this patient is more typical of UC.
C) Irritable bowel syndrome (IBS): IBS causes abdominal pain and altered bowel habits (diarrhoea or constipation), but it does not cause bloody diarrhoea or visible inflammation on colonoscopy. IBS is a functional gastrointestinal disorder, not an inflammatory disease.
D) Diverticulitis: Diverticulitis presents with localised left lower quadrant pain, fever, and leukocytosis, typically without bloody diarrhoea or continuous inflammation on colonoscopy.

Reference: Davidson 23rd; P-417

Reference: Davidson 23rd; P-572

Hepatitis B surface antigen
Hepatitis B surface antigen (HBsAg) is the main indicator of active infection, and a negative test for HBsAg makes HBV infection very unlikely.

Reference: Davidson 23rd; P-813

 Pregnancy is the most common cause of secondary amenorrhea (the absence of menstruation for more than three cycles in a previously menstruating woman). Davidson emphasizes that pregnancy should always be ruled out first in women presenting with amenorrhea. Harrison adds that other common causes of secondary amenorrhea include polycystic ovary syndrome (PCOS), hyperprolactinemia, and thyroid disorders.

Explanation: Chronic gastric ulcer is usually single; 90% are situated on the lesser curve within the antrum or at the junction between body and antral mucosa