What is often the initial sign of acute rheumatic fever in children?

Correct Answer: A

Rationale: Polyarthritis is indeed frequently the initial sign of acute rheumatic fever in children. It presents as joint pain, swelling, and redness. Carditis (inflammation of the heart), Erythema marginatum (a skin rash), and Sydenham chorea (involuntary muscle movements) are typically seen in the later stages of acute rheumatic fever and not as the initial sign.

Correct Answer: C

Rationale: The correct answer is C: Influenza. The influenza vaccine is produced using egg-based technology, so individuals with a severe egg allergy are at risk of an allergic reaction if vaccinated with the influenza vaccine. This is due to the potential presence of egg proteins in the vaccine. Choices A, B, and D are not contraindicated in children with severe egg allergy. The MMR and Varicella vaccines do not pose a risk for children with egg allergies, and the Hepatitis B vaccine is also safe for these individuals.

Correct Answer: C

Rationale: Absent breath sounds on the affected side are a primary symptom of congenital diaphragmatic hernia. Cyanosis, bradycardia, and tachypnea may also be present but are not the primary symptom. Cyanosis is a bluish discoloration of the skin due to poor oxygenation, bradycardia is a slower than normal heart rate, and tachypnea is rapid breathing.

Correct Answer: B

Rationale: The correct answer is B: Projectile vomiting. Pyloric stenosis in infants typically presents with projectile vomiting, which is forceful and projective in nature. This occurs due to the obstruction at the pylorus, leading to the stomach being unable to empty properly. Choices A, C, and D are incorrect. Bilious vomiting is more commonly associated with intestinal obstruction, blood in stools can occur in conditions such as necrotizing enterocolitis or allergic colitis, and failure to thrive is a nonspecific finding that can be seen in various pediatric conditions.

Correct Answer: C

Rationale: Croup is the correct answer. It is characterized by a harsh, barking cough due to inflammation of the upper airways, specifically the larynx and trachea. Asthma (Choice A) often presents with wheezing and shortness of breath, not a barking cough. Bronchiolitis (Choice B) typically causes wheezing and respiratory distress in infants. Pneumonia (Choice D) manifests with symptoms such as fever, productive cough, and chest pain, but not usually a barking cough.