Pneumocystis jirovecii

Vignette says a 33 year old male with a known history of HIV presents to the emergency department with a 7 days history of progressive shortness of breath, dry cough and fever; His CD4 count is 90 cells/μL despite being on antiretroviral therapy (ART); Vital signs show blood pressure of 110/70 mm of Hg, pulse rate of 108 bpm, respiratory rate of 22 breaths/min, oxygen saturation of 92% in RA and temperature of 100.9 F;  Lung auscultation reveals bilateral crackles; There is no evidence of peripheral edema or lymphadenopathy; CBC shows white blood cell count of 6,000 cells/mm3 with a mild lymphopenia; Chest X-ray shows bilateral diffuse reticulonodular infiltrates and CT scan of the chest shows ground-glass opacities, especially in the perihilar regions; ABG analysis shows pH of 7.48, PaCO2 of 30 mmHg, PaO2 of 50 mmHg and HCO3- of 22mEq/L; Microscopic examination of bronchoalveolar lavage (BAL) with silver stain shows disc shaped yeast; Diagnosis?

Diagnosis is Pneumocystis jirovecii.

Pneumocystis jirovecii pneumonia is caused by Pneumocystis jirovecii.

Etiologies:-

1. AIDS (i.e. CD4 < 200 cells/μL)

2. Immunosuppressive medications (e.g. chronic glucocorticoids, immunosuppressant agents)

Presents with fever, dyspnea and dry cough.

Diagnosis:-

1. Chest x-ray shows diffuse bilateral reticulonodular infiltrates.

2. LDH is elevated.

3. Microscopic examination of BAL with silver stain shows disc shaped yeast.

Management:-

1. Trimethoprim-sulfamethoxazole + Steroids; Indications for steroids in Pneumocystis

pneumonia is A-a gradient >35 mm Hg, or PaO2 <70, or SaO2 <92% in RA.

2. ART therapy.

Patients with AIDS (i.e. CD4 <200 cells/μL) and those on chronic glucocorticoid therapy

generally receive primary prophylaxis against Pneumocystis jirovecii pneumonia with

trimethoprim-sulfamethoxazole.