Monday, 20 September 2010

MRCP revision battle 16.2: Pneumocystis carinii

Pneumocystis carinii, AKA pneumocystis jiroveci, is a unicellular eukaryote.

It can cause pneumonia in patients with HIV and accounts for 40% of all AIDS-defining illness.
If CD 4 count is less than 200 PCP prophylaxis (=co-trimexazole) should be started.

Features of PCP:
  •  dyspnoea
  • dry cough
  • fever
  • few chest signs on examination
  • desaturation on exercise

CXR typically shows mid-lower bilateral interstitial infiltrates, but it may look normal.

Sputum cultures are often negative so BAL may be needed.

Treatment is:
  • co-trimexazole
  • IV pentamidine if severe
  • steroids if hypoxia
    • use of steroids decreases respiratory failure by 50% and death by 1/3)

On to battle 3 of the day and a classic condition - myasthenia gravis.