Medicine

Blood culture is the gold standard for diagnosing enteric fever caused by Salmonella Typhi or Paratyphi. It is most sensitive during the first week of illness, with a positivity rate of 60–80%. The Widal test is less specific due to cross-reactivity and is not preferred in modern practice. Bone marrow culture is highly sensitive but invasive, and stool culture is less reliable early in the disease

Explanation: Tuberculosis is the most common cause worldwide

Reference: Davidson 23rd; P-800

Reference: Davidson 23rd , Page : 1145, Box : 25.94

Illusion is a false interpretation.

Explanation: Neisseria gonorrhoeae is the most common organism causing urethritis

Reference: Davidson 23rd , Page : 481
Explanation : Amiodarone is probably the most effective drug currently available for controlling paroxysmal AF.

Explanation: Productive cough, changes in posture induce sputum production is a typical feature of Bronchiectasis

Reference: Davidson 23rd; P-582

Explanation: Absent a wave in JVP is found in Atrial fibrillation, Tricuspid regurgitation produces giant v waves

The direct antiglobulin (Coombs) test detects antibodies attached to RBCs, confirming autoimmune hemolysis.

Reference: Davidson 23rd; P-644

Explanation: ECG is the initial investigation for a patient with sudden severe chest pain

The classic pentad of TTP includes: 1) microangiopathic hemolytic anemia (MAHA), 2) thrombocytopenia, 3) neurological abnormalities (e.g., headache, confusion, seizures, stroke), 4) renal impairment, and 5) fever. While the full pentad is not always observed, MAHA and thrombocytopenia are almost universally present.

Reference: Davidson 23rd, Page: 756, Box: 20.36

Acute adrenal crisis presents with hypotension, shock, and electrolyte imbalances. Immediate IV hydrocortisone and isotonic fluids are lifesaving.

Ferritin reflects iron stores; low levels confirm iron deficiency. Note: ferritin is also an acute phase reactant and may be falsely elevated in inflammation.

Reference: Davidson 23rd, Page: 634, Box: 18.3

Explanation: please see question 45

Reference: Davidson 23rd, Page: 760 , Box : 20.41

Median nerve compression at the wrist causes carpal tunnel syndrome, often due to repetitive strain

Explanation: Oculomotor nerve is ithe 3rd Cranial nerve

Reference: Davidson 23rd; P-799

Explanation: Syphilis is caused by infection, through abrasions in the skin or mucous membranes, with the spirochaete Treponema pallidum.

Ref: Davidson 23rd; P-997

Reference: Davidson 23rd; P-547

Features of right heart failure in COPD patient indicates Cor pulmonale

The lung receives innervation from two main sources: the pulmonary plexus (a combination of parasympathetic and sympathetic innervation) and the phrenic nerve. The pulmonary plexus is at the root of the lung and consists of efferent and afferent autonomic nerve fibers.

Cardiac arrhythmias
Antipsychotic medications cause prolongation of the QTc interval, which may be associated with ventricular tachycardia, torsades de pointes and sudden death. If this occurs, treatment should be reviewed, with careful electrocardiographic monitoring and treatment of serious arrhythmias if necessary.

Infections are the leading cause of death in patients with systemic lupus erythematosus (SLE), as noted by Davidson. The immunosuppressive therapies used to control lupus, such as corticosteroids and cytotoxic drugs, increase the risk of severe infections. Harrison adds that while renal failure was once a leading cause of mortality in SLE, advances in treatment have improved long-term outcomes, with cardiovascular complications and infections now being more common causes of death.

UC typically involves continuous inflammation starting from the rectum, unlike Crohn’s disease which has skip lesions and can affect any GI segment.

Major Depressive Disorder (MDD) is characterized by a persistent depressed mood or anhedonia for at least 2 weeks, along with several other symptoms (e.g., changes in appetite/weight, sleep disturbance, fatigue, feelings of worthlessness/guilt, difficulty concentrating, suicidal ideation). The duration of symptoms (6 weeks) fits the diagnostic criteria for MDD.

Davidson 23rd; P-1118

Reference: Davidson 23rd; P-571

Ref: Davidson 23rd; P-974

The ‘a’ wave corresponds to right atrial contraction and occurs just before the first heart sound.
In atrial fibrillation the ‘a’ wave is absent.

Macleod 14th/52

The clinical features of bone pain, muscle weakness, and fractures, combined with the laboratory findings of low calcium, low phosphate, and high alkaline phosphatase (indicating increased bone turnover), are classic for osteomalacia (adult form of rickets). This is primarily caused by Vitamin D deficiency, which impairs calcium and phosphate absorption and mineralization of bone matrix. Chronic kidney disease can impair Vitamin D activation, making it a common cause of osteomalacia.

P. vivax and P. ovale may persist in liver cells as  dormant form hypnozoites capable of developing  into merozoites months or years later
Thus the first attack of clinical malaria may occur  long after the patient has left the endemic area, and  the disease may relapse after treatment with drugs  that only kill the erythrocytic stage of the parasite
P. falciparum, P. knowlesi and P. malariae have no  persistent exoerythrocytic phase but recrudescence  of fever may result from multiplication of parasites  in red cells that have not been eliminated by  treatment and immune processes

Mode of Transmission-Sexually from partner, Neonate  exposed to infected secretions in birth canal

Nocturia is often the earliest symptom, due to impaired urine concentrating ability.

Reference: Davidson 23rd , Page : 516
Explanation : The most common major manifestation of rheumatic fever is arthritis.

Explanation: Escherichia coli and various streptococci, particularly Strep. milleri, are the most common organisms

Explanation: Fever with Severe headache and photophobia, neck stiffnss usually suggestive of meningitis

Headache indicates pituitary cause of weight gain.

Reference: Davidson 23rd; P-801

Myeloma kidney results from light chain deposition, hypercalcemia, and hyperuricemia.

Explanation: Chronic kidney disease (CKD) refers to an irreversible deterioration in renal function that usually develops over a period of years Initially, it manifests only as a biochemical abnormality but, eventually, loss of the excretory, metabolic and endocrine functions of the kidney leads to the clinical symptoms and signs of renal failure, collectively referred to as uraemia

Ankylosing spondylitis is an inflammatory spondyloarthropathy affecting young males, presenting with back pain that improves with activity, and is associated with HLA-B27.

Whipple’s triad confirmed
Patient had symptoms of hypoglycaemia
Low blood glucose measured at the time of symptoms
Symptoms resolved on correction of hypoglycaemia

Explanation: Tests for ACPA are positive in about 70% of cases and are highly specific for RA, occurring in many patients before clinical onset of the disease

The clinical features here are of fever in a patient at high risk of neutropenia. This is an oncological emergency. Patients are at risk of neutropenia at any point during their systemic anti-cancer therapy treatment cycle, with the highest risk typically 10–14 days after a treatment. In patients with potential neutropenic sepsis high-dose broad spectrum intravenous antibiotics should be commenced, ideally within 1 hour of admission, without awaiting test results. In this  should not delay the first dose of antibiotic therapy. Test results may later inform changes to antimicrobial therapy and its duration.

Reference: Davidson 23rd; P-676

According to Davidson, diabetic nephropathy is the most typical cause of nephrotic syndrome in adults. Diabetic nephropathy leads to glomerular damage resulting in proteinuria, hypoalbuminemia, and edoema. Harrison emphasises that strict control of blood sugar and blood pressure can help slow the progression of diabetic nephropathy and reduce the risk of end-stage renal disease.

Explanation: Prolactin is the hormone that stimulates milk production in the mammary glands. Davidson explains that prolactin levels rise during pregnancy and after childbirth, promoting lactation. Harrison adds that oxytocin is responsible for milk ejection, but prolactin is key to maintaining milk production.