Lung Infections in HIV - Differential Diagnosis Framework



Disease by CD4 Count:

Any CD4 Count:

 • Mycobacterium tuberculosis, Bacterial pneumonia

 • Seasonal influenza

CD4 <200:

 • Pneumocystis jirovecii pneumonia (PJP), MAI, Cryptococcal pneumonia, Extrapulmonary tuberculosis, Blastomycosis

CD4 <50-100:

 • Toxoplasmosis

 • Histoplasmosis, Coccidioidomycosis, CMV, Mycobacterium avium, Mycobacterium kansasii, Invasive aspergillosis, Rhodococcus equi, Pseudomonas



FUNGAL PNEUMONIAS:

 • Weight loss, lethargy, fever

 • Disseminated

 • Pleuritic CP

 • Cough, dyspnea

 • (Less common since cART)



Aspergillus Pneumonia:

 • 3 syndromes: ABPA, Mycetoma, Invasive Aspergillosis

 • High fever, cough, and dyspnea, wheezing

 • Pleuritic chest pain may be present. Hemoptysis (occasionally massive) - angioinvasive disease.

 • CT: Halo sign



Coccidioides Immitis Pneumonia:

 • "Flu-like", Valley fever

 • Fever, weight loss, Lymphadenopathy, Chest pain, cough

 • Polymorphic skin lesions (papules, pustules, erythematous nodules, plaques)



Cryptococcus Neoformans Pneumonia:

 • Cough and dyspnea

 • Lobar consolidation or nodular infiltrates



PJP Pneumonia:

 • Risk: Can produce significant depression of the phagocytic function of alveolar macrophages in HIV

 • Lung Exam: Can be normal

 • Fever (It's usually low if you have HIV), Chills, Dry cough or wheezing, Shortness of breath, Fatigue, Chest pain or tightness when you breathe, Weight loss



Histoplasma Capsulatum Pneumonia:

 • (Fever, weight loss), Lymphadenopathy, dry cough or dyspnea, hepatomegaly,

 • Oral mucosal ulcers, erythema nodosum or erythema multiforme,

 • Multiple skin lesions (pustules, crusted papules),

 • Cytopenias



VIRAL PNEUMONIAS:



Influenza:

 • Rapid onset of a "flu-like syndrome" consisting of dry cough, myalgias, headache and high fever



CMV:

 • 2-4 week subacute course

 • Nonproductive cough, dyspnea, and fever



BACTERIAL PNEUMONIAS:

Most Common:

 • Streptococcus pneumoniae - 20% of pneumonias

 • Haemophilus influenzae - 10-15% of pneumonias

 • Staphylococcus aureus



Nocardia Pneumonia:

 • Chest pain, cough, bloody sputum, sweats, chills, weakness, lack of appetite, weight loss

 • Imaging: Irregular nodules or infiltrates-necrotizing

 • Lung most commonly infected



M. Tuberculosis Pneumonia:

 • Upper lung zone infiltrates

 • Cavities

 • Fever, chills, night sweats, anorexia, productive cough, and occasional hemoptysis

 • Lymphadenopathy, CNS involvement



MAI Pneumonia:

 • Constitutional symptoms (fever, weight loss, anorexia) Hepatosplenomegaly, lymphadenopathy,

 • Abdominal pain, chronic diarrhea, cytopenias



M. Kansasii



Legionella:

 • Nausea, vomiting, and diarrhea

 • Hyponatremia

 • Elevated hepatic transaminases

 • C-reactive protein levels >100 mg/L

 • Rhabdomyolysis (rare)



Co-MRSA Pneumonia:

 • PVL virulence factor

 • May cause rapidly progressive necrotizing pneumonia



Rhodococcus Equi Pneumonia:

 • Indolent course with fever, cough and cavitary infiltrates, mimicking TB



Chlamydia Pneumoniae:

 • Focal pneumonia, pleural effusion, or bronchitis



Mycoplasma Pneumoniae:

 • Cough (reported in 100% of cases), anemia, arthralgia, dyspnea, sore throat along with fever, rales, interstitial infiltrates or lobar pneumonia



Coxiella Burnetii:

 • Fever, headache, non-productive cough, myalgia

 • Lung nodules possible in HIV



PARASITIC PNEUMONIAS:

 • Toxoplasma gondii - Fever, nonproductive cough, and dyspnea

 • Strongyloides stercoralis - Worms in lungs

 • Cryptosporidium, and Microsporidium



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