Fungi involved: Mucor, Rhizopus, Absidia, Rhizomucor (Order Mucorales, Class Zygomycetes)
Inhalation is the usual route of infection.
High risk patients:
(1) diabetic ketoacidosis
(2) solid organ transplantation
(3) prolonged neutropenia
(4) hematopoietic stem cell transplantation, especially with corticosteroid therapy for a graft-vs-host reaction
Clinical findings:
(1) eye or orbital pain
(2) facial pain
(3) sinusitis
(4) fever may be present or absent
(5) unilateral or bilateral chemosis
(6) periorbital cellulitis
(7) unilateral or bilateral proptosis
(8) blurry vision to vision loss
(9) ophthalmoplegia and cranial nerve dysfunction
(10) ulceration through the hard palate
Complications associated with high mortality:
(1) disseminated fungal infection
(2) angioinvasion with thrombosis and necrosis, especially of the cavernous sinus and/or carotid artery
Diagnosis often requires biopsy of infected tissue. Fungal hyphae lacking cross walls are seen on microscopic examination. Culture may show false positives as well as false negatives.
