This child likely has infectious mononucleosis caused by Epstein-Barr virus (EBV), characterized by fever, sore throat, cervical lymphadenopathy, fatigue, and splenomegaly. A palpable spleen is a hallmark of EBV in children.

Toronto Notes 2023 – Pediatrics, “Infectious Mononucleosis”:

“Key features include fever, pharyngitis, lymphadenopathy, and splenomegaly. Children may have milder symptoms but often exhibit palpable spleen.”

MCCQE1 Objectives (Pediatrics > 75-2: Infectious Disease):

“Candidates should recognize common viral syndromes such as EBV and identify complications including splenomegaly.”

Other options (renal mass, ascites, etc.) are inconsistent with this viral presentation.

====================================================

This case features hallmark traits of antisocial personality disorder: disregard for social norms, criminal behavior, lack of remorse, impulsivity, and a history of conduct disorder (suggested by childhood ADHD and likely early behavioral problems).

Toronto Notes 2023 – Psychiatry, Personality Disorders:

“Antisocial personality disorder is characterized by disregard for rights of others, impulsivity, deceitfulness, lack of remorse, and criminal activity beginning in adolescence.”

MCCQE1 Objectives – Psychiatry > Personality Disorders:

“Candidates must distinguish antisocial personality disorder by a pattern of behavior that violates the rights of others, with evidence of conduct disorder before age 15.”

Other options do not explain the full behavioral pattern, especially the criminality and lack of remorse.

====================================================

The presence of suicidal ideation in a minor mandates urgent assessment to ensure safety and access mental health care. Disclosure of sexual orientation should be handled delicately and is not urgent compared to suicidal risk.

Toronto Notes 2023 – Psychiatry, “Child and Adolescent Psychiatry” Section:

“Any adolescent disclosing suicidal ideation should be referred for urgent mental health evaluation. Concurrent issues such as sexual orientation may contribute to distress and should be addressed with appropriate support over time.”

MCCQE1 Objectives (Psychiatry > 79-2: Suicide Risk Assessment):

“Candidates must immediately refer for psychiatric assessment when a minor reports suicidal ideation, regardless of other social or developmental concerns.”

Antidepressants (A) may be appropriate but must follow specialist evaluation. Encouraging disclosure (B) or peer groups (C) is premature without ensuring safety.

Comprehensive and Detailed Explanation:

At 20 weeks’ gestation, the uterine fundus typically reaches the umbilicus. If the fundal height is lower than expected at a stated gestational age of 26 weeks, the most likely explanation—especially with no prior care—is a dating error.

Toronto Notes 2023 – Obstetrics:

“Fundal height at the umbilicus corresponds to ~20 weeks. In women lacking early prenatal care, dating errors are common causes of fundal height discrepancy.”

MCCQE1 Objectives (Obstetrics > 80-3: Routine Antenatal Care):

“Candidates must interpret fundal height and reconcile discrepancies with gestational age.”

IUGR and oligohydramnios are possible but require imaging confirmation. Bicornuate uterus may cause fundal shape anomalies but not significant dating discrepancy. A mole (D) would increase, not decrease, size.

—

Comprehensive and Detailed Explanation:

This patient is likely experiencing extrapyramidal symptoms (dysphagia/dystonia) due to haloperidol. Switching to an atypical antipsychotic (like quetiapine), which has a lower risk of EPS, is appropriate. Dysphagia in the context of antipsychotic use requires prompt medication review.

Toronto Notes 2023 – Psychiatry, “Antipsychotics and Extrapyramidal Effects”:

“Dysphagia can be a sign of extrapyramidal side effects. Consider switching to an atypical antipsychotic with lower EPS risk.”

MCCQE1 Objectives (Psychiatry > 71-5: Antipsychotic Adverse Effects):

“Candidates must recognize and manage EPS, including drug-induced dysphagia.”

Dantrolene (C) is for neuroleptic malignant syndrome, not isolated dysphagia. Laryngoscopy (B) may be useful later but not first-line. Reassurance (D) is unsafe. Lorazepam (E) may help in dystonia but doesn ' t address the root cause.

Chlamydia trachomatis is the most common cause of cervicitis in young sexually active women and frequently presents with dysuria, dyspareunia, intermenstrual bleeding, and a normal vulvovaginal exam. It may be asymptomatic or have subtle signs and often affects the endocervix.

Toronto Notes 2023 – Gynecology, “Sexually Transmitted Infections” Section:

“Chlamydia is the most common bacterial STI. Symptoms may include intermenstrual bleeding, postcoital bleeding, dyspareunia, mucopurulent cervical discharge, and dysuria. The vulva and vagina may appear normal.”

MCCQE1 Objectives (Obstetrics and Gynecology > 82-1: Abnormal Uterine Bleeding):

“Candidates should evaluate STI-related cervicitis as a common cause of postcoital and intermenstrual bleeding in young women.”

Other options:

A. Actinomyces israelii is associated with IUD use, not relevant here.

B. Herpes simplex virus usually presents with painful ulcerations, not abnormal bleeding.

C. Treponema pallidum (syphilis) causes painless ulcers or systemic symptoms in later stages.

D. HPV causes warts or asymptomatic cervical dysplasia, not acute symptoms.

====================================================

The most important pre-vaccination history to elicit is any previous anaphylaxis to vaccine components. mRNA COVID-19 vaccines (e.g., Pfizer-BioNTech and Moderna) may contain polyethylene glycol (PEG), a potential allergen. This is a contraindication to administration.

Toronto Notes 2023 – Infectious Disease & Immunization Chapter:

“Absolute contraindications to mRNA COVID-19 vaccination include a documented anaphylactic reaction to a component of the vaccine such as polyethylene glycol (PEG).”

MCCQE1 Objectives – Population Health > Preventive Medicine > Immunizations:

“The candidate must be able to assess for contraindications prior to immunization, including anaphylaxis to previous vaccines or components.”

Breastfeeding and occupational exposure (Options B and D) do not preclude vaccination. Current immunosuppression (Option C) may affect vaccine efficacy but is not a contraindication unless specifically advised.

====================================================

Button batteries lodged in the esophagus require urgent endoscopic removal due to risk of tissue necrosis, perforation, and tracheoesophageal fistula within hours. Batteries beyond the esophagus may pass spontaneously if the child is asymptomatic.

Toronto Notes 2023 – Pediatrics, “Foreign Body Ingestion”:

“Button batteries in the esophagus are medical emergencies and must be removed immediately. Batteries in the stomach or intestines may be observed if the child is asymptomatic.”

MCCQE1 Objectives (Pediatrics > 78-2: Gastrointestinal Emergencies):

“Candidates must identify when foreign body ingestion poses immediate risk and requires emergency intervention.”

Batteries in the stomach or intestines (A–C, E) usually pass without complication, especially if the child is asymptomatic and the battery is < 2 cm.

====================================================

This patient is in the precontemplation stage because he does not recognize his alcohol use as a problem and has no intention to change his drinking behavior. Despite evidence of harm—heavy daily intake (1.2 L vodka/day) and current symptoms compatible with alcohol withdrawal/autonomic hyperactivity (tremor, diaphoresis, tachycardia, nausea/vomiting)—he frames his drinking as “social” and explicitly states he plans to continue. In the transtheoretical model, precontemplation describes individuals who are unaware, unwilling, or resistant to change within the foreseeable future. Contemplation would involve ambivalence and acknowledgement of a potential problem; preparation includes intention and planning to change soon; action involves active behavior change; maintenance refers to sustaining change over time. MCCQE objectives emphasize identifying readiness to change to guide counseling: in precontemplation, the clinician focuses on building rapport, providing clear, nonjudgmental feedback about risks, exploring discrepancies between goals and behavior, and using motivational interviewing to enhance insight rather than pushing immediate abstinence plans.

This ABG reveals primary respiratory acidosis (↓pH, ↑PaCO₂, normal HCO₃), likely from hypoventilation due to postoperative pain, sedation, or narcotics. PaO₂ is also low, suggesting inadequate oxygenation.

Toronto Notes 2023 – Respiratory, “Postoperative Respiratory Complications”:

“Postoperative respiratory acidosis results from hypoventilation, often due to pain, sedatives, or poor respiratory effort. Assess airway, breathing, and support oxygenation.”

MCCQE1 Objectives (Internal Medicine > 44-3: Acid-Base Disturbances):

“Candidates must recognize respiratory acidosis on ABG and relate findings to common postoperative complications.”

Metabolic acidosis (C) would show ↓HCO₃. Compensated alkalosis (D) would show opposite ABG changes. Hypermetabolic states increase respiratory drive, not decrease it.