Correct Answer: D

Rationale: The correct answer is D, as gastroesophageal reflux disease (GERD) in infants typically presents with symptoms such as spitting up, failure to thrive, excessive crying, and respiratory problems due to aspiration. Bilious vomiting is not a common symptom of GERD in infants and may indicate a different or more severe condition, such as intestinal obstruction or other gastrointestinal issues. Therefore, choices A, B, and C are all expected clinical manifestations of GERD in a 6-month-old child, making option D the correct answer.

Correct Answer: A

Rationale: Enemas are contraindicated in cases of suspected appendicitis because they can increase the risk of perforation. The pressure from the enema can exacerbate inflammation and potentially lead to the rupture of the appendix. Palpating the abdomen gently is essential for diagnosing appendicitis, as it helps identify the characteristic signs like rebound tenderness. Antibiotics are commonly used to treat the infection associated with appendicitis, and antipyretics are administered to manage fever, which is a common symptom of the condition. Therefore, enemas are the intervention to avoid in suspected appendicitis cases.

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: Frequent spitting up is indeed a common symptom of gastroesophageal reflux in infants. It is caused by the backward flow of stomach contents into the esophagus, leading to infants regurgitating milk or formula shortly after feeding. Projectile vomiting (choice A) is more commonly associated with conditions like pyloric stenosis rather than gastroesophageal reflux. Bilious vomiting (choice B) often indicates an obstruction in the gastrointestinal tract. Diarrhea (choice D) is not typically a primary symptom of gastroesophageal reflux in infants.

Correct Answer: B

Rationale: The correct answer is B: Anorexia and malaise. The prodromal phase of acute viral hepatitis is characterized by nonspecific symptoms such as anorexia (loss of appetite) and malaise (general feeling of discomfort). These symptoms typically precede the more specific signs of jaundice, dark urine, and pale stools that manifest in the icteric phase. Choices A, C, and D are incorrect because bruising and lethargy, fatigability and jaundice, and dark urine and pale stools are typically seen in later stages of acute viral hepatitis, not in the prodromal phase.