A 12-month-old girl is brought to her pediatrician for a checkup and vaccines. The patient’s mother wants to send her to daycare but is worried about exposure to unvaccinated children and other potential sources of infection. The toddler was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines. She does not walk yet but stands in place and can say a few words. The toddler drinks formula and eats a mixture of soft vegetables and pureed meals. She has no current medications. On physical exam, the vital signs include: temperature 37.0°C (98.6°F), blood pressure 95/50 mm Hg, pulse 130/min, and respiratory rate 28/min. The patient is alert and responsive. The remainder of the exam is unremarkable. Which of the following is most appropriate for this patient at this visit?

Gross motor workup and evaluation

A 35-year-old man presents with burning penile lesions 3 days after unprotected intercourse. He has no prior history of similar lesions. Which of the following best differentiates primary from recurrent HSV infection?

Systemic symptoms and bilateral lymphadenopathy

A 24-year-old woman, gravida 1, para 0, at 39 weeks' gestation, is admitted to the hospital in active labor. She currently has contractions occurring every 3–5 minutes. For the past 3 days, she has had burning pain in the vulvar area associated with intense itching. Her pregnancy has been uneventful. She has a history of genital herpes at the age of 16, which was treated with acyclovir. Her vital signs are within normal limits. Genital examination shows grouped vesicles on an erythematous base over the vulvar region. Pelvic examination shows rupture of membranes and that the cervix is 3 cm dilated. Which of the following is the most appropriate next step in management?

Oral acyclovir therapy and cesarean delivery

Tocolytic therapy until lesions are crusted

Oral acyclovir therapy and vaginal delivery

Topical acyclovir and vaginal delivery

Topical acyclovir and cesarean delivery

A pathologist receives a patient sample for analysis. Cells in the sample are first labeled with fluorescent antibodies and then passed across a laser beam in a single file of particles. The light scatter and fluorescent intensity of the particles are plotted on a graph; this information is used to characterize the sample. This laboratory method would be most useful to establish the diagnosis of a patient with which of the following?

Pancytopenia and deep vein thrombosis with intermittent hemoglobinuria

Ventricular septal defect and facial dysmorphism with low T-lymphocyte count

Painless generalized lymphadenopathy with monomorphic cells and interspersed benign histiocytes on histology

Multiple opportunistic infections with decreased CD4 counts

Vesicular lesions with dermatomal distribution and dendritic corneal ulcers

A mother delivers in a rural area under the guidance of a skilled care attendant. Which of the following statements is incorrect regarding the care provided by the skilled care attendant at birth?

Start breastfeeding as early as possible

Clear the eyes with a sterile swab

Dry the baby thoroughly and stimulate breathing

An 8-day-old male infant presents to the pediatrician with a high-grade fever and poor feeding pattern with regurgitation of milk after each feeding. On examination the infant showed abnormal movements, hypertonia, and exaggerated DTRs. The mother explains that during her pregnancy, she has tried to eat only unprocessed foods and unpasteurized dairy so that her baby would not be exposed to any preservatives or unhealthy chemicals. Which of the following characteristics describes the causative agent that caused this illness in the infant?

Gram-positive, facultative intracellular, motile bacilli

Gram-negative, maltose fermenting diplococci

Gram-positive, catalase-negative, alpha hemolytic, optochin sensitive cocci

Gram-positive, catalase-negative, beta hemolytic, bacitracin resistant cocci

Gram-negative, lactose-fermenting, facultative anaerobic bacilli

Neonatal HSV for USMLE Step 2 CK: High-Yield Pediatrics Lessons

Transmission - The Unwanted Gift

Perinatal (Intrapartum): The major route (~85%), occurring during passage through an infected birth canal (usually HSV-2).
Other Routes:
- Intrauterine (Congenital): ~5%
- Postnatal: ~10%, via direct contact with an infected individual (e.g., oral HSV-1).
Risk Factors for Transmission:
- Primary maternal infection near delivery (highest risk).
- Invasive fetal monitoring.
- Prolonged rupture of membranes.

⭐ Most neonates with HSV are born to mothers who are asymptomatic and have no known history of genital herpes.

Clinical Picture - The Deadly Triad

Neonatal HSV vesicles on infant abdomen and umbilical stump

Neonatal HSV manifests in three overlapping patterns. Early diagnosis is critical as untreated mortality is high.

Feature	Skin, Eye, Mouth (SEM)	CNS Disease	Disseminated Disease
Presentation	Localized vesicles	Seizures, lethargy, poor feeding	Sepsis-like, shock, hepatitis
Onset	10-12 days	16-19 days	10-12 days
Mortality (Untreated)	Low, but high morbidity	~50%	>85%
Key Features	Vesicular clusters on skin, conjunctivitis, ulcerative oral lesions.	Temporal lobe involvement, abnormal CSF.	Multi-organ failure (liver, lungs, adrenals), DIC.

Diagnosis - The Viral Verdict

Prompt and accurate diagnosis is critical. The primary method involves viral detection via PCR.

Gold Standard: HSV PCR is the test of choice, offering high sensitivity and specificity.
- Essential Samples: Obtain from multiple sites to maximize yield.
  - Surface: Swabs from skin/vesicles, conjunctiva, oro- and nasopharynx.
  - Systemic: CSF (mandatory if CNS disease is suspected), and whole blood.
Supportive Findings:
- CSF Analysis: Reveals lymphocytic pleocytosis with elevated protein.
- LFTs: Elevated transaminases are a key marker for disseminated disease.

⭐ Exam Pearl: While viral culture was historically used, HSV PCR is now the superior and standard method, especially for CSF, where it is the most sensitive test for HSV encephalitis.

Management - Acyclovir's Ace

Primary Therapy: IV Acyclovir
- Dose: 60 mg/kg/day IV, divided every 8 hours (q8h).
- Duration: Varies by disease classification:
  - Skin, Eye, Mouth (SEM) disease: 14 days.
  - CNS or Disseminated disease: 21 days.
Supportive Care
- Essential for managing hydration (IV fluids), respiratory failure, and seizures.
Suppressive Therapy
- Oral acyclovir is recommended for 6 months post-treatment for infants with CNS or SEM disease to improve neurodevelopmental outcomes.

⭐ Untreated disseminated neonatal HSV has a mortality rate exceeding 85%. Early acyclovir is life-saving.

High‑Yield Points - ⚡ Biggest Takeaways

HSV-2 is the most common cause, typically transmitted intrapartum.

Presents as a triad: Skin-Eye-Mouth (SEM) disease, CNS disease, or disseminated disease.

Disseminated HSV mimics neonatal sepsis and carries the highest mortality.

Gold standard diagnosis is HSV PCR on CSF, blood, and vesicular fluid.

Treatment is high-dose IV Acyclovir for all forms.

C-section is indicated for mothers with active genital lesions during labor.

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Neonatal HSV