Gambaran OTOMIKOSISOtomycosis (Aspergillus Niger)

• Description:Otomycosis is an infection of the external ear or external auditory canal caused by invasion of the epidermis by fungal organisms. The fungi are most commonly airborne but may be autoinoculated from other infected sites. Many types of fungi have been cultured from the ear canal, but the most common pathogenic types are Aspergillus and Candida species. Itching is the predominant symptom associated with otomycosis; however, with severe infections pain will also occur. The diagnosis of otomycosis is based both on the,clinical appearance and fungal cultures. The tympanic membrane and skin of the deep canal of this patient are covered with tiny black dots which resemble carbon particles. These are the conidiophores of Aspergillus niger.

Otomycosis-Aspergillus Speciea

• Description:Otomycosis caused by Aspergillus species often reveals a white, fluffy, cotton like material (fungal hyphae). The anterior canal wall is covered with a thin layer of white, fluffy, cotton like material. This represents the branching hyphae of an Aspergillus species.

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Otomycosis-aspergillus fumigatus

• Description:Yellowish, black, or grayish dots (conidiophores) may be found scattered over the involved area. The deep canal often contains moist sheets of keratin shed from the lining, which typically resemble wet tissue paper. After prolonged treatment with topical antibiotic drugs for acute otitis externa, this ear canal, at follow up, contained numerous brown fruiting heads (conidiophores), indicating colonization of the external canal with an Aspergillus species; probably Aspergillus fumigatus.

Severe Aspergillus Niger Otitis Externa 1• Description:T

he presence of Aspergillus niger is revealed by the evidence of brown and black conidiophores surrounded by purulent material

Severe otomycosis-Aspergillus Niger

• Description:After the canal has been partially debrided (middle), granular inflammatory changes in the underlying epithelium are revealed by the appearance of spontaneous bleeding. The purulent de bris has now been removed (right), and the tympanic membrane over the short process of the malleus and the malleus handle shows a granular myringitis. This was produced by the invasion of the superficial layer of the tympanic membrane by Aspergillus niger. Treatment includes careful microdebridement and the application of specific antimycotic topical agents. In the case of a mixed bacterial and fungal infection, alternating treatment with topical antibiotics and topical antimycotic agents may be required.

Otomycosis-Aspergillus Niger

• Description:The deep canal is grossly edematous and there is a drop of purulent exudate surrounded by numerous needle like fungal hyphae. The organism cultured was Aspergillus niger.

Histopathology-Aspergillus Niger

• Description:Under low magnification, infection by Aspergillus niger is characterized by a row of fungal hyphae. Numerous conidiophores can be seen on the external surface and on the medial or deep surface a collection of chronic inflammatory cells, representing pus, is visible. H&E 38 x

Histopathology-Aspergillus Niger

• Description:The fruiting head, or conidiophore, of Aspergillus niger is characterized by a central sporangium with radiating spokes, surrounded by numerous tiny spores on the periphery. H&E 560 x

Histopathology-Aspergillus Niger

• Description:Under higher magnification (right), the spores which have separated from the conidiophores can be seen. H&E 1250 x .

Aspergillus Niger-Scanning Electron Microscope

• Description:A scanning electron microscopic view of Aspergillus niger shows clusters of conidiophores lying upon a tangled web of hyphae. 2500 x .

OtomycosisCandida Albicans

• Description:In contrast to Aspergillus, otomycosis caused by Candida does not show any visibly discernible evidence of fungi, and consequently a diagnosis cannot be made during otoscopic examination.

Candida Albicans-Plate culture

• Description:The typical discrete yeast colonies of Candida albicans usually appear within 3 days of culture on Saboraud's modified agar

Candida Albicans-Histopathology

• Description:Potassium hydroxide preparations or, as in the right slide, a routine histologic section of the exudate, will reveal the presence of multiple branching septate pseudohyphae in clusters of grape like budding spores. The pseudohyphae measure from 2 to 4 microns m in diameter and the ovoid spores vary from 3 to 5 microns. H&E 200x.