Clinical Image: The Hacking Cough
Welcome to another Clinical Image from the case files of the Brown EM Residency
HPI: A 48-year-old female with a history of asthma and HIV presents to the ED with fevers and non-productive cough. Her symptoms began four days ago. Her last CD4 count 5 months prior was 195 with a viral load of 130,000. She has not been taking her anti-retrovirals over the past three weeks.
ROS: Associated symptoms include headache, sore throat, myalgia, poor appetite, and shortness of breath. No recent travel or sick contacts. Lives at home with two cats and a pet parakeet. Denies dizziness, wheezing, chest pain, abdominal pain, nausea, vomiting, diarrhea, urinary symptoms, or rash.
Vital Signs: T 97.3, HR 100, RR 22, BP 128/68, SpO2 90% on RA
Pertinent physical exam: Patient is alert, orientated and comfortable appearing. Oropharynx does not have any lesions or exudate. Moist mucous membranes. TM’s are normal. No focal or gross neurological deficits. Neck is supple. Heart is tachycardic. Abdomen soft, non-tender. Lungs sounds are rhonchorous. No rashes. No other pertinent exam findings.
A chest x-ray was obtained:
What’s the diagnosis?
Pneumocystis (PCP) Pneumonia
Follow up (surprise) question: What is the most common cause of pneumonia in HIV infected patients in the United States and Western Europe?
Streptococcus pneumoniae
However, PCP pneumonia is the most common opportunistic infection in AIDS patients (CD4 <200), of which this patient meets the criteria. So, what is it and how is it diagnosed?:
Causative microbe is pneumocystis jirovecii, previously known as pneumocystis carinii, which has been identified as a fungus; however does not respond to antifungals.
Presenting symptoms are typically non-productive cough, fever, and shortness of breath over days to weeks.
Radiographic findings commonly demonstrate diffuse fine reticular interstitial infiltrates, often “out of proportion” to clinical symptoms. Although 15% of patients will have no radiographic findings.
Differential includes community acquire pneumonia (CAP) -both typical and atypical pathogens, CMV infection, TB, MAC, histoplasmosis or coccidiomycosis.
Lactate dehydrogenase levels are typically elevated (>220 U/L) and reflect the degree of lung injury.
ABG analysis will often demonstrate hypoxemia and an increased A-a gradient.
Suspect PCP pneumonia in immunocompromised patients with unexplained hypoxemia.
Diagnosis is typically confirmed with bronchoalveolar lavage (BAL).
How is it treated:
Initial empiric therapy is PO Bactrim (mild to moderate disease) or IV (severe disease or GI upset) for three weeks . The dose is 15-20 mg/kg/day of the trimethoprim component.
In patients with sulfa allergies or significant side effects to treatment with Bactrim consider IV pentamidine who have severe infection, and dapsone plus either trimethoprim or clindamycin/primaquine in patients who have mild to moderate infection.
Administer steroids to patients with PaO2 < 70 mmHg or an A-a gradient >35 mmHg (40 mg PO BID x 21 days). Adjunctive steroids are not recommended in patients without HIV infection.
For patients with CD4 counts less than 200 prophylaxis is considered key to prevent recurrence (1 DS tablet of Bactrim QD).
Case Conclusion:
The patient was started on antibiotics to cover both CAP (ceftriaxone and azithromycin) as well as PCP (Bactrim). Patient had a BAL performed inpatient confirming the PCP infection. She improved on high dose Bactrim and steroids and was discharged home on prophylactic Bactrim and HARRT therapy.
References:
1: Knipe, Henry, et. al. Pneumocystis Pneumonia. <http://radiopaedia.org/articles/pneumocystis-pneumonia>. 2016.
2: Sax, Paul. Clinical Presentation and Diagnosis of Pneumocystis Pulmonary Infection in HIV-Infected Patients. UptoDate. <www.uptodate.com>. 2016.
3: Sax, Paul. Treatment and prevention of Pneumocystis infection in HIV-infected patients. UptoDate. <www.uptodate.com>. 2016.
4: Tintinalli, et. al. Emergency Medicine. 8th Edition. 2016. 1052-1053.
Shout out to Dr. Tony Zhang for this case!
The contents of this case were deliberately altered to protect the identity of the patient. All content in this report are for educational purposes only. The patient consented to the use of these images.
Faculty Reviewer: Dr. Alyson McGregor
Author. Dr. Thomas Ross