Rhinosinusitis

Question 1

Aspergillus

Answer 1

Rhinosinusitis
• *Filamentous fungus (mold)
• *Septate hyphae w/ 45°, V-shaped, dichotomous branching
• *Conidia (chains) ubiquitous in air, soil, decaying matter
• Aspergillus fumigatus, A. niger, A. flavus, A. nidulans, A. terreus
• In immunosuppressed esp. *neutropenic
LAB
• ELISA for Aspergillus *galactomannan antigen
Virulence
- *Angioinvasive
Manifestations
• Primarily *lungs
• Allergic aspergillosis
• Aspergilloma usually 2° to TB
• Acute, invasive pulmonary aspergillosis in severely immunocompromised
• Also sinuses, eyes, ears, skin
• Can disseminate in severely immunocompromised, esp. *neutropenic, cause brain abscess, necrotic skin lesions
*Paranasal sinus aspergillosis
• *Non-invasive aspergilloma
• Usually non-immunosuppressed indiv.
• Symptom usually nasal blockage
• *Invasive form
• Usually immunosuppressed patients
• Similar to rhinocerebral mucormycosis
• Symptoms incl. fever, rhinitis, signs of invasion into orbit
• Prevention incl. HEPA filters for high risk patient rooms
Treatment
1. **Debridement + antifungal + deal w/ underlying immunosuppressive illness, control diabetes
a. *IV voriconazole

Question 2

Rhizopus oryzae

Answer 2

Rhinosinusitis
• Ubiquitous
• Opportunist
• *Affinity for iron-rich, acidic environments
o *Classically affects diabetics w/ ketoacidosis
• *Distinct hyphae
o *Broad (5-15 µm diam.), irregularly branched, right-angle branching, rare septations
• *‘Ribbon-like’ ‘Moose antlers’
o Fragile
• Lack of septation?
Virulence
• *Ketone reductase
• *Angioinvasive
• Relatively avirulent
• Siderophore rhizoferrin
- Hyphae
Symptoms rhinocerebral mucormycosis
• Blood vessels, nerves damaged
• Often facial numbness
• Signs of orbital involvement include periorbital edema, proptosis, blindness
• May have black eschars on palate or nose
Treatment
• *Aggressive surgical debridement (often disfiguring, requiring removal palate, nasal cartilages, orbit) + IV lipid amphotericin B (often months) + control of diabetes