Aspergillosis
Andrew C. Walls, BSc
Chad Jessup, MD, MS
Martin C. Mihm, Jr., MD
Key Facts
Terminology
Cutaneous fungal infection due to angioinvasive Aspergillus spp.
Clinical Issues
Key risk factor: Immunocompromise
Primary cutaneous lesions arise from direct local inoculation/colonization
Secondary cutaneous lesions arise from hematogenous dissemination usually of sinobronchopulmonary origin
Microscopic Pathology
2-4 µm septated hyaline hyphae with dichotomous branching at 45° angle
Angioinvasion, overlying tissue ischemic necrosis and hemorrhage
 Classic cutaneous aspergillosis lesion demonstrates an evolving violaceous nodule with central ulceration  and eschar formation  . |
 H&E (left) and GMS (right) stains of cutaneous aspergillosis demonstrate numerous septated fungal hyphae  with dichotomous 45° angle branching  . (Courtesy L Thompson, MD.) |
TERMINOLOGY
Definitions
Cutaneous fungal infection due to angioinvasive Aspergillus spp.
Primary cutaneous lesions arise from direct local inoculation/colonization
Host is most often immunocompromised or, rarely immunocmpetent
Secondary cutaneous lesions arise from hematogenous dissemination, usually of sinobronchopulmonary origin, in immunocompromised host
ETIOLOGY/PATHOGENESIS
Environmental Exposure
Ubiquitous soil and water-dwelling fungal organism
Contact made through direct inhalation of spores (conidia) or primary inoculation of skin
Hospital renovations or construction may increase ambient spore count
Infectious Agents
A. fumigatus, A. flavus most common (70%)
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