Staccato cough plus conjunctivitis in a 2-month-old suggests chlamydial pneumonia. Know the exam-safe evaluation: CXR and nasopharyngeal testing.
A 2-month-old with staccato cough plus conjunctivitis history should prompt evaluation for Chlamydia trachomatis with chest radiography and nasopharyngeal diagnostic testing.
A foster parent brings in a 2 mo infant with concern for cough. The parent states the child has been having poor sleep due to this persistent cough. The coughing is described as short and sharp coughs that comes in bursts and is often follow by difficulty breathing. The parent also states the baby has been having intermittent eye discharge that causes occasional eye swelling.
What is a reasonable next step in evaluation for this child?
Answer Options:
The keyed answer is functionally correct, but the wording is non-ideal for modern guideline language: clinicians generally order a nasopharyngeal specimen for Chlamydia trachomatis testing (NAAT or culture, depending on lab validation) plus a CXR. Per the CDC STI Treatment Guidelines (2021) and consistent AAP Red Book recommendations, infant chlamydial pneumonia (often age 1–3 months) is suggested by afebrile, repetitive “staccato” cough, tachypnea, and a history of conjunctivitis; CXR classically shows hyperinflation and bilateral interstitial infiltrates.
Boards commonly test that this is not simple nasolacrimal duct obstruction, and it is not a routine “neonatal sepsis work-up” presentation in an otherwise stable 2-month-old with a characteristic chlamydial syndrome.
| Option | What It Tests / Implies | Why It’s Wrong Here |
| Educate parent on lacrimal duct massage technique and follow up with primary care doctor | Nasolacrimal duct obstruction management | Doesn’t explain paroxysmal/staccato cough with breathing difficulty; misses systemic infectious syndrome. |
| Nasopharyngeal swab to isolate for cause of infection and CXR | Targeted evaluation for infant chlamydial pneumonia (CXR + NP diagnostic testing) | Best match to syndrome; modern nuance is “NAAT/culture” rather than vague “isolate.” |
| Neonatal septic work-up and initiation of IV antibiotics | Full neonatal sepsis pathway | A 2-month-old with classic chlamydial phenotype is typically afebrile and not automatically a “neonate sepsis work-up” unless ill/toxic or febrile. |
| Start the infant on azithromycin to prevent further spread of illness and admit for observation. | Empiric macrolide + admit “to prevent spread” | Rationale is off: treatment is to cure infant infection (and manage contacts), not primarily “prevent spread,” and admission depends on severity; also question asks *evaluation* first. |
In a 1–3 month infant with afebrile staccato cough and conjunctivitis history, think *Chlamydia trachomatis* pneumonia → CXR + nasopharyngeal diagnostic testing (NAAT/culture) and treat appropriately.
The stem blends a common benign complaint (eye discharge) with a high-yield infectious syndrome clue (“short, sharp coughs…in bursts” at 2 months). The board-relevant move is to integrate timing + cough quality + conjunctivitis and choose targeted evaluation for chlamydial pneumonia—not reassurance or an automatic sepsis algorithm.
A 6-week-old presents with tachypnea and repetitive staccato cough. No fever. Mother had untreated cervicitis in pregnancy. Best next diagnostic step?
A 10-day-old has conjunctival injection and watery-to-mucopurulent discharge. Afebrile, well-appearing. Most likely etiology?
CXR in suspected infant chlamydial pneumonia most commonly shows:
A 7-week-old with suspected chlamydial pneumonia now appears lethargic with poor perfusion and temp 38.5°C. Next step?
Which statement is most accurate regarding treatment of infant chlamydial pneumonia?
How would your diagnostic and disposition approach change between (1) a well-appearing, afebrile 2-month-old with staccato cough and conjunctivitis history and (2) a febrile, ill-appearing 6-week-old with copious purulent eye discharge and chemosis?
Q1: What single clinical clue should make me think of infant chlamydial pneumonia on boards?
A: The ABP/PEM-style clue is an afebrile staccato cough in a 1–3 month infant, often with a preceding conjunctivitis history (CDC STI Guidelines 2021; AAP Red Book).
Q2: What tests are typically used to confirm infant chlamydial infection?
A: A nasopharyngeal specimen for C. trachomatis testing (NAAT where validated, or culture) plus supportive CXR findings; conjunctival specimens may also be tested when eye disease is present (CDC 2021).
Q3: When do I escalate to a neonatal/young infant sepsis work-up?
A: Board algorithms prioritize fever and toxic appearance; if the infant is febrile or ill-appearing, treat as high-risk and broaden work-up/admit regardless of a suspected chlamydial syndrome.
Q4: Why not just treat immediately without testing?
A: Many clinicians treat when suspicion is high, but exam questions that ask for “evaluation” often want the paired step of CXR + pathogen testing; it’s the most defensible guideline-consistent evaluation approach.
Find this and other Pediatric Emergency Medicine exam prep questions in Med-Challenger Pediatric Emergency Medicine 3rd Edition Exam Review with CME
Try for free and save. Ace your exams and meet your CME/MOC requirements.
No matter your program, no matter the size, Med-Challenger for Groups and Institutions can better prepare your program or group, fulfill industry requirements, and increase test scores.
For personal medical education that includes board's prep, MOC, and CME requirements, Med-Challenger has you covered in Family Medicine, Emergency Medicine, Internal Medicine, Pediatrics, Pediatric Emergency Medicine, OBGYN, Physician Assistants, and Nurse Practitioners.
Family Medicine board‑style question: 32‑y/o with headache, weight gain, and cold intolerance — consider primary hypothyroidism; exam pearls on...
When do infants begin sustained eye contact? Exam-focused short answer and teaching points on infant gaze fixation for pediatric exam prep.
Learn why melena—not anemia—is the key symptom of right-sided colon cancer in this week’s most-missed PA exam question and what it teaches...