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.