infectious diseases
Aspergillosis
Pathophysiology of Aspergillosis
Invasive infections are usually acquired by inhalation of spores or, occasionally, by direct invasion through damaged skin. Major risk factorsfor aspergillosis include Neutropenia when prolonged (typically > 7 days) Long-term high-dose corticosteroid therapy Organ transplantation (especially bone marrow transplantation with graft-vs-host disease [GVHD]) Hereditary disorders of neutrophil function (eg, chronic granulomatous disease) species tend to infect open spaces, such as pulmonary cavities caused by previous lung disorders (eg, Bronchiectasis , A. fumigatusis the most common cause of invasive pulmonary disease. Allergic Bronchopulmonary Aspergillosis (ABPA) None Focal infections, typically in the lung, sometimes form a fungus ball (aspergilloma), a characteristic growth of tangled masses of hyphae, with fibrin exudate and few inflammatory cells, typically encapsulated by fibrous tissue. Occasionally, there is some local invasion of tissue at the periphery of the cavity, but usually the fungus just resides within the cavity with no appreciable local invasion. A chronic form of invasive aspergillosis occasionally occurs, particularly in patients taking corticosteroids long-term and those with Chronic Granulomatous Disease (CGD) , which is characterized by a hereditary phagocytic cell defect. species can also cause Endophthalmitis after trauma or surgery to the eye or by hematogenous seeding and can infect intravascular and intracardiac prostheses. Primary superficial aspergillosis is uncommon but may occur in burns; beneath occlusive dressings; after corneal trauma (keratitis); or in the sinuses, mouth, nose, or ear canal. 