Makindo Medical Notes.com

CSF may be unrevealing. Opening pressure is often high. Higher numbers of fungal organisms in the CSF is associated with higher opening pressures. Must check cryptococcal antigen

About

• Affects immunocompromised.
• An encapsulated yeast 2 to 15 um in greatest diameter
• Very thick-walled sugar-based capsule which can prevent immune attacks
• Needs aggressive antifungal therapy
• Can cause pneumonia and meningitis

Aetiology

• Infection from bird droppings and the soil enters via the pulmonary route
• Pulmonary infection can via blood spread to the brain
• Seen in AIDS and those with abnormal Cell mediated Immunity (see below)

Defective cell mediated immunity

• AIDS, Immunosuppression for organ transplantation
• Reticuloendothelial malignancy, Corticosteroid treatment, Sarcoidosis

Clinical

• Nausea, Headache, fever, malaise, can be subtle
• Basal meningitis causes cranial nerve palsies
• Stroke like syndrome, Space occupying lesion
• Chest disease - fever, malaise, cough with scant sputum, ARDS
• Cryptococcal skin lesions look like molluscum contagiosum
• Myocarditis, Hepatitis, Chorioretinitis, Renal abscess

Investigations

• FBC, U&E, CRP, HIV test , CXR - may be abnormal
• CT Head: first in immunocompromised with high risk of mass lesions
• CSF: elevated pressure and protein and lymphocytes. Cryptococcal meningitis often increases ICP. This results from a polysaccharide capsule (contributing to the fungus' large size) that blocks the transport of CSF through the arachnoid granulations, raising ICP. High ICP is more common in HIV+ due to higher fungal burdens
• CSF India ink stain usually shows encapsulated budding cells in up to 90% of cases
• Cryptococcal antigen test needed to make the diagnosis
• Blood/urine/sputum and even bone marrow can be cultured

Cryptococcal abscesses

Management

• IV liposomal Amphotericin B is given for 2 weeks. Beware of nephrotoxicity.
• Ongoing Fluconazole OD for AIDS patients.
• Consider commencing HAART at 2 weeks later to minimise risk of IRIS