Medical Q&A : find your quiz answers here !

Which of the following is the most common cause of acute glomerulonephritis in children?

A. Post-streptococcal glomerulonephritis
B. IgA nephropathy
C. Henoch-Schönlein purpura
D. lupus nephritis

The most common cause of acute glomerulonephritis in children is:

A. Post-streptococcal glomerulonephritis

Explanation:
Post-streptococcal glomerulonephritis (PSGN) is the most common cause of acute glomerulonephritis in children, typically occurring after an infection with certain strains of group A streptococcus (commonly a throat or skin infection). This immune-mediated condition happens due to the formation of immune complexes, which deposit in the glomeruli, causing inflammation and damage. It usually presents with hematuria, proteinuria, edema, and hypertension.

Other causes:

• IgA nephropathy: Although relatively common, IgA nephropathy (Berger’s disease) tends to present more frequently in young adults rather than children.
  
  
• Henoch-Schönlein purpura: This is a small vessel vasculitis that can cause glomerulonephritis, but it is less common than post-streptococcal glomerulonephritis.
  
  
• lupus nephritis: This is associated with systemic lupus erythematosus (SLE) and is a less common cause of glomerulonephritis in children.
  

Let me know if you need further clarification!

 

Which of the following is the most common cause of chronic cough in nonsmokers?

A. Asthma
B. Gastroesophageal reflux disease (GERD)
C. Postnasal drip
D. Chronic bronchitis

The most common cause of chronic cough in nonsmokers is postnasal drip (C).

Explanation:

1. Postnasal drip: It is the leading cause of chronic cough in nonsmokers. The secretions from the nose or sinuses drain down the back of the throat, triggering a cough reflex. This condition can result from allergies, sinus infections, or irritants.
   
   
2. Asthma (A): Asthma is another common cause, but it often presents with additional symptoms such as wheezing and shortness of breath. In some cases, asthma can cause cough as the only symptom (cough-variant asthma).
   
   
3. Gastroesophageal reflux disease (GERD) (B): GERD can cause chronic cough when stomach acid irritates the esophagus and respiratory tract. It is a common cause but generally less frequent than postnasal drip.
   
   
4. Chronic bronchitis (D): Chronic bronchitis is typically associated with smoking and environmental exposures. In nonsmokers, it is not a common cause of chronic cough.
   

In clinical practice, a combination of patient history and examination would guide toward the most likely cause, but postnasal drip remains the most common in nonsmokers.

 

Which of the following is the primary cause of chronic pancreatitis in adults?

A. Alcohol abuse
B. Gallstones
C. Hypertriglyceridemia
D. Autoimmune pancreatitis
The primary cause of chronic pancreatitis in adults is A. Alcohol abuse.

Explanation:
Chronic pancreatitis is a long-standing inflammation of the pancreas that alters its normal structure and functions. In adults, alcohol abuse is the most common cause of chronic pancreatitis, accounting for about 70-80% of cases. Prolonged excessive alcohol consumption leads to repeated episodes of pancreatic inflammation, which can cause irreversible damage, fibrosis, and loss of both exocrine and endocrine function over time.

• Gallstones (B) are more commonly associated with acute pancreatitis rather than chronic pancreatitis.
• Hypertriglyceridemia (C) can cause pancreatitis but is not the leading cause of chronic pancreatitis.
• Autoimmune pancreatitis (D) is a rare form of chronic pancreatitis that is part of a systemic autoimmune disorder, but it is not a leading cause compared to alcohol abuse.

 

Which of the following is the most common cause of acute scrotal pain in children?

A. Testicular torsion
B. Epididymitis
C. Inguinal hernia
D. Hydrocele

The most common cause of acute scrotal pain in children is A. Testicular torsion.

Explanation:

• Testicular torsion occurs when the spermatic cord becomes twisted, cutting off the blood supply to the testicle. This is a surgical emergency and the most common cause of acute scrotal pain in children, particularly during puberty. If not treated promptly, it can lead to ischemia and loss of the affected testicle.
• Epididymitis (B) is more common in sexually active adolescents and adults but is rare in prepubescent boys.
• Inguinal hernia (C) can cause scrotal pain but is less common as a primary cause of acute scrotal pain in children.
• Hydrocele (D) typically causes painless scrotal swelling and is not associated with acute pain.

Testicular torsion should always be suspected in children presenting with acute scrotal pain, as early diagnosis and treatment (within 6 hours) are critical to saving the testicle.

 

Which of the following is the first-line treatment for attention-deficit/hyperactivity disorder (ADHD) in children?

A. Stimulants
B. Non-stimulants
C. Behavioral therapy
D. Antidepressants

The first-line treatment for attention-deficit/hyperactivity disorder (ADHD) in children is A. Stimulants.

Explanation:

• Stimulants are considered the first-line treatment for ADHD in children because they have the most evidence for efficacy in reducing ADHD symptoms such as inattention, hyperactivity, and impulsivity. Medications such as methylphenidate and amphetamines are commonly prescribed and have been shown to help children manage their ADHD symptoms effectively.
• Non-stimulants (B), such as atomoxetine, may be used if stimulants are not effective or cause unacceptable side effects, but they are typically not first-line treatments.
• Behavioral therapy (C) is often recommended in combination with medication, particularly for younger children, but it is usually not the first-line treatment alone.
• Antidepressants (D) are generally not used as a first-line treatment for ADHD, though they may be considered in specific cases, particularly when ADHD coexists with other conditions like depression or anxiety.

 

Which of the following is the most common cause of acute bacterial sinusitis?

A. Streptococcus pneumoniae
B. Haemophilus influenzae
C. Moraxella catarrhalis
D. Staphylococcus aureus

The most common cause of acute bacterial sinusitis is A. Streptococcus pneumoniae.

Explanation:

• Streptococcus pneumoniae and Haemophilus influenzae are the two most common bacterial pathogens responsible for acute bacterial sinusitis, with Streptococcus pneumoniae being the leading cause.
• Haemophilus influenzae (B) is also a common cause but is slightly less frequent than Streptococcus pneumoniae.
• Moraxella catarrhalis (C) can cause sinusitis, particularly in children, but it is less common than Streptococcus pneumoniae and Haemophilus influenzae.
• Staphylococcus aureus (D) is a less common cause of acute bacterial sinusitis but can be implicated in chronic sinus infections or more severe cases.

Therefore, Streptococcus pneumoniae is considered the most common bacterial cause of acute bacterial sinusitis.

 

Which of the following is the most common cause of acute epiglottitis in children?

A. Streptococcus pneumoniae
B. Haemophilus influenzae type b
C. Staphylococcus aureus
D. Group A Streptococcus

The correct answer is:

B. Haemophilus influenzae type b

Explanation: Acute epiglottitis, a potentially life-threatening condition characterized by inflammation of the epiglottis, is most commonly caused by Haemophilus influenzae type b (Hib), especially in children. This bacterial infection leads to swelling of the epiglottis, which can rapidly obstruct the airway if untreated.

Before the widespread use of the Hib vaccine, Haemophilus influenzae type b was the primary causative organism in pediatric cases of acute epiglottitis. Since the introduction and routine administration of the Hib vaccine, the incidence of Hib-induced epiglottitis in vaccinated populations has significantly decreased. However, Hib remains the most common cause in children where vaccination coverage is incomplete or in regions where Hib vaccination is not routine.

Other pathogens, such as Streptococcus pneumoniae, Staphylococcus aureus, and Group A Streptococcus, can also cause epiglottitis, but they are far less common causes in children compared to Hib.

 

Which of the following is the first-line treatment for chronic insomnia?

A. Benzodiazepines
B. Cognitive behavioral therapy (CBT)
C. Melatonin
D. Antihistamines
The correct answer is:

B. Cognitive Behavioral Therapy (CBT)

Explanation: Cognitive Behavioral Therapy for Insomnia (CBT-I) is considered the first-line treatment for chronic insomnia. CBT-I is a structured program that helps individuals address and change thoughts and behaviors that contribute to sleep problems. It includes techniques such as stimulus control, sleep restriction, cognitive restructuring, and relaxation training. Research has shown that CBT-I is effective in improving sleep quality and duration in the long term, and it has fewer risks and side effects compared to pharmacological treatments.

Why Not the Other Options?

• A. Benzodiazepines: Although benzodiazepines may be prescribed for short-term relief in some cases, they are generally not recommended as a first-line treatment for chronic insomnia due to the risks of dependency, tolerance, and side effects.
• C. Melatonin: While melatonin supplements may help with short-term sleep issues, particularly with circadian rhythm disorders, they are not as effective as CBT-I for long-term management of chronic insomnia.
• D. Antihistamines: Antihistamines (like diphenhydramine) are sometimes used as sleep aids, but they are not recommended for chronic insomnia due to limited efficacy, potential for tolerance, and undesirable side effects such as daytime drowsiness.

CBT-I is preferred because it targets the underlying causes of insomnia without the risks associated with long-term medication use.

 

Which of the following is the primary cause of central diabetes insipidus?

A. Pituitary adenoma
B. Head trauma
C. Genetic mutation
D. Autoimmune destruction of hypothalamus

The primary cause of central diabetes insipidus is most commonly:

D. Autoimmune destruction of hypothalamus

Explanation:
Central diabetes insipidus is a condition characterized by a deficiency in the hormone vasopressin (antidiuretic hormone or ADH), which is produced in the hypothalamus and stored in the posterior pituitary gland. This deficiency results in the kidneys being unable to concentrate urine, leading to excessive urination and thirst.

1. Autoimmune destruction of the hypothalamus can damage the cells responsible for producing vasopressin, leading to central diabetes insipidus. Autoimmune mechanisms are one of the primary causes, where the body's immune system mistakenly attacks the hypothalamus, affecting ADH production.
   
   
2. Pituitary adenoma (Option A) and head trauma (Option B) can also lead to central diabetes insipidus by damaging the hypothalamic-pituitary axis, but they are secondary causes rather than the primary cause.
   
   
3. Genetic mutation (Option C) may cause certain forms of diabetes insipidus, particularly nephrogenic diabetes insipidus, which is related to the kidneys' response to ADH rather than a central (brain-related) production issue.
   

 

Which of the following is the most common cause of acute prostatitis?

A. Escherichia coli
B. Staphylococcus aureus
C. Streptococcus faecalis
D. Pseudomonas aeruginosa

The most common cause of acute prostatitis is:

A. Escherichia coli (E. coli)

Explanation:
Acute bacterial prostatitis is an infection of the prostate gland that often occurs due to bacterial entry into the prostate. The most common causative organism is Escherichia coli, which is responsible for the majority of acute prostatitis cases. Other common pathogens include Klebsiella, Proteus, and other Gram-negative organisms.

• Escherichia coli (E. coli): This bacterium is frequently found in the urinary tract and is a common cause of urinary tract infections (UTIs). It can enter the prostate via the urethra or due to a reflux of infected urine, leading to acute inflammation.
• Staphylococcus aureus: Although it can cause infections, it is less commonly associated with acute prostatitis.
• Streptococcus faecalis (Enterococcus faecalis): This organism can sometimes be involved, but it is not the most common cause.
• Pseudomonas aeruginosa: This is also a potential cause, especially in hospital-acquired cases, but it is not as common as E. coli.

In summary, Escherichia coli is the primary bacterium responsible for acute prostatitis, especially in community-acquired cases.

 

Which of the following is the first-line treatment for primary hyperparathyroidism?

A. Bisphosphonates
B. Calcimimetics
C. Parathyroidectomy
D. Vitamin D supplementation

The correct answer is C. Parathyroidectomy.

Explanation:
Primary hyperparathyroidism is a condition characterized by the excessive secretion of parathyroid hormone (PTH) by one or more of the parathyroid glands. This leads to elevated calcium levels in the blood (hypercalcemia). The definitive treatment for primary hyperparathyroidism is parathyroidectomy, which involves the surgical removal of the overactive parathyroid gland(s).

Here’s why parathyroidectomy is the first-line treatment:

• Definitive Cure: Parathyroidectomy is considered curative, especially when there is a single adenoma or hyperplasia causing the condition.
• Symptom Relief: Surgery can relieve symptoms such as bone pain, kidney stones, fatigue, and gastrointestinal issues caused by hypercalcemia.
• Long-Term Outcomes: It provides the best long-term results in terms of normalizing calcium levels and preventing complications.

Why the other options are incorrect:

• A. Bisphosphonates: These drugs can help reduce bone resorption and temporarily lower calcium levels but are not curative for primary hyperparathyroidism.
• B. Calcimimetics: Calcimimetics like cinacalcet can reduce PTH secretion but are typically used in patients who are not surgical candidates or have secondary hyperparathyroidism, such as in chronic kidney disease.
• D. Vitamin D supplementation: While vitamin D deficiency may exacerbate hyperparathyroidism, supplementation alone is not a treatment for primary hyperparathyroidism. It may be used as an adjunct therapy if the patient has concurrent vitamin D deficiency.

In summary, parathyroidectomy remains the first-line treatment for primary hyperparathyroidism due to its curative potential and effectiveness in controlling hypercalcemia.

 

Which of the following is the first-line treatment for primary hyperparathyroidism?

A. Bisphosphonates
B. Calcimimetics
C. Parathyroidectomy
D. Vitamin D supplementation


The correct answer is C. Parathyroidectomy.

Explanation:
Primary hyperparathyroidism (PHPT) is a condition characterized by excessive secretion of parathyroid hormone (PTH), which leads to hypercalcemia (elevated blood calcium levels). The main cause is usually a benign adenoma of the parathyroid gland.

First-Line Treatment: Parathyroidectomy

• Parathyroidectomy is considered the first-line treatment for primary hyperparathyroidism, particularly when patients meet certain criteria (e.g., symptomatic hypercalcemia, significant elevation of serum calcium, osteoporosis, or reduced kidney function).
• Surgery is the definitive treatment that addresses the root cause (e.g., removal of the adenoma or hyperplastic parathyroid glands) and often results in normalization of calcium levels.

Other Treatment Options:

• A. Bisphosphonates: These are used to manage hypercalcemia by inhibiting bone resorption but are not considered a first-line or curative treatment.
• B. Calcimimetics: These medications (e.g., cinacalcet) can help reduce PTH levels and serum calcium, particularly in patients who are not surgical candidates or have secondary hyperparathyroidism. However, they are not the primary treatment for PHPT.
• D. Vitamin D Supplementation: While vitamin D supplementation may be used to address coexisting vitamin D deficiency, it is not a primary treatment for hyperparathyroidism and should be used cautiously to avoid worsening hypercalcemia.

In summary, parathyroidectomy is the definitive and first-line treatment for primary hyperparathyroidism, especially when surgery is indicated based on clinical guidelines.

 

Which of the following is the most common cause of secondary hypertension in children?

A. Renal artery stenosis
B. Coarctation of the aorta
C. Pheochromocytoma
D. Hyperaldosteronism

The correct answer is A. Renal artery stenosis.

Explanation:
Secondary hypertension in children is hypertension caused by an underlying medical condition. The most common causes vary by age group, but renal causes are the most common overall, particularly in younger children.

1. Renal Artery Stenosis:

• Renal artery stenosis, a narrowing of the renal arteries, is the most frequent cause of secondary hypertension in children. It leads to reduced blood flow to the kidney, activating the renin-angiotensin-aldosterone system (RAAS) and causing hypertension.
• It is commonly associated with congenital abnormalities, fibromuscular dysplasia, or systemic diseases such as Takayasu arteritis.

2. Other Options:

• B. Coarctation of the Aorta: Coarctation of the aorta is another important cause of secondary hypertension in children, especially older children. It leads to elevated blood pressure in the upper extremities but lower pressures in the legs.
• C. Pheochromocytoma: Pheochromocytoma is a rare cause of secondary hypertension in children. It involves a catecholamine-secreting tumor that leads to paroxysmal or sustained hypertension, often with symptoms like headaches and palpitations.
• D. Hyperaldosteronism: Hyperaldosteronism (e.g., Conn’s syndrome) is a rare cause of hypertension in children. It is more commonly seen in adults and results from excessive aldosterone secretion, leading to sodium retention and hypokalemia.

 

Which of the following is the most common cause of upper respiratory tract infections in children?

A. Rhinovirus
B. Adenovirus
C. Respiratory syncytial virus (RSV)
D. Influenza virus

The most common cause of upper respiratory tract infections (URTIs) in children is:

A. Rhinovirus

Explanation:

1. Rhinovirus:
   
   • Rhinoviruses are the leading cause of the common cold, which is the most prevalent upper respiratory tract infection in children.
   • They are highly contagious and spread through respiratory droplets and contact with contaminated surfaces.
   • Symptoms include nasal congestion, runny nose, sore throat, and cough.
2. Adenovirus:
   
   • Adenoviruses can also cause respiratory tract infections, but they are less common compared to rhinoviruses.
   • They can lead to a broader range of illnesses, including pharyngitis, conjunctivitis, and gastroenteritis.
3. Respiratory Syncytial Virus (RSV):
   
   • RSV primarily causes lower respiratory tract infections, such as bronchiolitis and pneumonia, especially in infants and young children.
   • While it can cause upper respiratory symptoms, it is not the most common cause.
4. Influenza Virus:
   
   • Influenza is associated with seasonal outbreaks and can cause both upper and lower respiratory tract infections.
   • It is less common than rhinovirus as a cause of routine URTIs in children.

Conclusion:
Rhinovirus is the most frequent cause of upper respiratory tract infections in children, making A the correct answer.

 

Which of the following is the primary cause of nephrotic syndrome in adults?

A. Focal segmental glomerulosclerosis (FSGS)
B. Membranous nephropathy
C. Minimal change disease
D. Diabetic nephropathy

The primary cause of nephrotic syndrome in adults is:

B. Membranous nephropathy

Explanation:

1. Membranous Nephropathy:
   
   • Membranous nephropathy is the most common primary cause of nephrotic syndrome in adults.
   • It is characterized by the deposition of immune complexes on the subepithelial side of the glomerular basement membrane, leading to thickening and disruption of normal filtration.
   • The condition is often idiopathic but may be secondary to autoimmune diseases, infections, or medications.
   • Clinical features include significant proteinuria, hypoalbuminemia, edema, and hyperlipidemia.
2. Focal Segmental Glomerulosclerosis (FSGS):
   
   • FSGS is another common cause of nephrotic syndrome in adults but is more often seen as the primary cause in African American populations.
   • It is characterized by segmental scarring of some glomeruli and can lead to progressive renal insufficiency.
3. Minimal Change Disease:
   
   • While this is the most common cause of nephrotic syndrome in children, it accounts for fewer cases in adults.
   • It is characterized by diffuse effacement of podocyte foot processes on electron microscopy.
4. Diabetic Nephropathy:
   
   • Diabetic nephropathy is a leading cause of nephrotic-range proteinuria and chronic kidney disease worldwide.
   • However, it is classified as a secondary cause of nephrotic syndrome, associated with long-standing diabetes mellitus.

Conclusion:
The most common primary cause of nephrotic syndrome in adults is membranous nephropathy, making B the correct answer.

 

Which of the following is the most common cause of secondary amenorrhea?

A. Pregnancy
B. Polycystic ovary syndrome (PCOS)
C. Hypothalamic amenorrhea
D. Hyperprolactinemia

The most common cause of secondary amenorrhea is:

A. Pregnancy

Explanation:

1. Pregnancy:
   
   • Pregnancy is the most common cause of secondary amenorrhea in women of reproductive age.
   • It should always be the first condition to rule out when evaluating a patient with missed menstrual periods.
   • Diagnosis can be easily confirmed with a urine or serum beta-hCG test.
2. Polycystic Ovary Syndrome (PCOS):
   
   • PCOS is a common cause of secondary amenorrhea but is not as frequent as pregnancy.
   • It is associated with hormonal imbalances, irregular ovulation, and features like hyperandrogenism (e.g., hirsutism, acne).
   • Diagnosis is based on the Rotterdam criteria (two out of three: irregular cycles, hyperandrogenism, polycystic ovaries on ultrasound).
3. Hypothalamic Amenorrhea:
   
   • This occurs due to disruption of the hypothalamic-pituitary-ovarian (HPO) axis, often caused by stress, significant weight loss, or excessive exercise.
   • It is a less common cause compared to pregnancy and PCOS.
4. Hyperprolactinemia:
   
   • Elevated prolactin levels can suppress gonadotropin-releasing hormone (GnRH) secretion, leading to secondary amenorrhea.
   • Causes include pituitary adenomas (prolactinomas), medications, and hypothyroidism.

Diagnostic Approach:
When evaluating secondary amenorrhea, start with:

1. Pregnancy test (beta-hCG) to rule out pregnancy.
2. Hormonal tests to assess FSH, LH, prolactin, TSH, and androgens.
3. History and physical examination to evaluate for PCOS, hypothalamic causes, or other systemic conditions.

Conclusion:
Pregnancy is the most common and first consideration when assessing secondary amenorrhea, making A the correct answer.

 

Which of the following is the primary treatment for acute cholecystitis?

A. Antibiotics
B. Cholecystectomy
C. Endoscopic retrograde cholangiopancreatography (ERCP)
D. Percutaneous cholecystostomy


The primary treatment for acute cholecystitis is:

B. Cholecystectomy

Explanation:
Acute cholecystitis is inflammation of the gallbladder, most commonly caused by gallstone obstruction of the cystic duct. The treatment aims to resolve the inflammation and prevent recurrence. Here's a breakdown of the options:

1. Antibiotics (Option A):
   
   • Antibiotics are used as initial therapy to control infection and inflammation, especially in cases of bacterial infection. However, they are not a definitive treatment. Antibiotics alone do not resolve the underlying issue of gallstone obstruction.
2. Cholecystectomy (Option B):
   
   • Gold Standard Treatment: Surgical removal of the gallbladder (cholecystectomy) is the definitive treatment for acute cholecystitis.
   • Timing: Early laparoscopic cholecystectomy (within 72 hours of symptom onset) is preferred as it reduces complications and recurrence risk. Delaying surgery increases the risk of complications such as gallbladder perforation or abscess formation.
3. Endoscopic Retrograde Cholangiopancreatography (ERCP) (Option C):
   
   • ERCP is used for cases of choledocholithiasis (stones in the common bile duct) or complications like ascending cholangitis. It is not the primary treatment for acute cholecystitis unless there is concomitant bile duct involvement.
4. Percutaneous Cholecystostomy (Option D):
   
   • This is a minimally invasive drainage procedure, typically reserved for critically ill or high-risk surgical patients who cannot undergo cholecystectomy. It is a temporizing measure, not the standard treatment.

 

Which of the following is the first-line treatment for hypercalcemia of malignancy?

A. Bisphosphonates
B. Calcitonin
C. Denosumab
D. Hydration

The first-line treatment for hypercalcemia of malignancy is:

D. Hydration

Explanation:
Hypercalcemia of malignancy is a condition in which there is an elevated calcium level in the blood due to cancer. The cornerstone of initial management is aggressive intravenous (IV) hydration with normal saline to restore intravascular volume and enhance renal calcium excretion. This helps reduce serum calcium levels by promoting calcium diuresis.

After hydration, additional treatments may be required to address the underlying hypercalcemia:

1. Bisphosphonates (e.g., zoledronic acid, pamidronate):
   
   • Used after hydration to inhibit bone resorption by osteoclasts.
   • Effective in lowering calcium levels over days.
2. Calcitonin:
   
   • Provides a more rapid but temporary reduction in calcium levels.
   • Often used as a bridge therapy until bisphosphonates take effect.
3. Denosumab:
   
   • A monoclonal antibody that inhibits RANKL, preventing osteoclast activation.
   • Reserved for patients who do not respond to bisphosphonates or those with contraindications.

Summary:
While bisphosphonates and calcitonin play a role in treatment, hydration is the essential first-line intervention for managing hypercalcemia of malignancy, as it directly addresses dehydration and promotes calcium excretion.

 

What is the most common cause of hypercalcemia in hospitalized patients?

A- Hyperparathyroidism
B- Malignancy
C- Vitamin D intoxication
D- Sarcoidosis
The most common cause of hypercalcemia in hospitalized patients is:

B- Malignancy

Explanation:
Hypercalcemia in hospitalized patients is most commonly due to malignancy. Several cancers, such as lung, breast, and multiple myeloma, can lead to hypercalcemia through two primary mechanisms:

1. Humoral Hypercalcemia of Malignancy (HHM):
   
   • Tumors secrete parathyroid hormone-related peptide (PTHrP), which mimics the action of PTH, leading to increased bone resorption and renal tubular calcium reabsorption.
   • This is the most common mechanism for hypercalcemia in malignancy.
2. Local Osteolytic Hypercalcemia:
   
   • Tumor cells release cytokines and factors that activate osteoclasts, causing bone resorption and calcium release into the bloodstream.

Other Options:

• A. Hyperparathyroidism:
  This is the most common cause of hypercalcemia in the general (outpatient) population but not in hospitalized patients.
  
  
• C. Vitamin D intoxication:
  Excess vitamin D increases calcium absorption from the intestines but is much less common.
  
  
• D. Sarcoidosis:
  Granulomatous diseases like sarcoidosis can cause hypercalcemia through increased 1,25-dihydroxyvitamin D production, but this is also rare compared to malignancy in hospitalized patients.
  

Summary:
Malignancy is the most common cause of hypercalcemia in hospitalized patients due to PTHrP production or direct bone destruction.

 

Which of the following conditions is characterized by a "butterfly rash" on the face?

A- Dermatomyositis
B- systemic lupus erythematosus
C- Rosacea
D- Psoriasis

The correct answer is:

B- systemic lupus erythematosus (SLE)

Explanation:
systemic lupus erythematosus (SLE) is an autoimmune condition characterized by a variety of clinical manifestations, including the classic butterfly rash (malar rash) that appears on the face. This rash:

• Covers the cheeks and the bridge of the nose.
• Often spares the nasolabial folds.
• Is erythematous and may be photosensitive, meaning it worsens with sun exposure.

Why not the others?

• A. Dermatomyositis:
  This condition presents with a heliotrope rash (a purplish rash around the eyelids) and Gottron's papules over the knuckles, not a butterfly-shaped rash.
  
  
• C. Rosacea:
  Rosacea causes facial redness, often involving the cheeks and nose, but it does not spare the nasolabial folds and lacks the specific butterfly pattern of SLE.
  
  
• D. Psoriasis:
  Psoriasis causes well-demarcated, silvery-scaled plaques, commonly on the scalp, elbows, knees, and other extensor surfaces, but not a butterfly-shaped rash.
  

Summary:
The butterfly rash is a hallmark feature of systemic lupus erythematosus (SLE) and helps distinguish it from other skin conditions.