Botryomycosis; is a rare chronic granulomatous bacterial infection that affects the skin, and sometimes the viscera. : 255 Botryomycosis has been known to affect humans, horses, cattle, swine, dogs and cats. Presentation
Associated conditions
There are only a handful of documented cases of botryomycosis in humans, and its pathogenesis is not completely understood. However, it is usually described in individuals with impaired immunity, or with an underlying disease such as diabetes mellitus, cystic fibrosis or HIV infection. Causes
Staphylococcus aureus is usually the organism that causes the infection, however it can also be caused by Pseudomonas aeruginosa, Pneumocystis carinii, Proteus spp. and Actinobacillus lignieresii or other species of bacteria. The anatomic structure of its lesion is similar to that of actinomycosis and eumycetoma, and its granules resemble the sulfur granules of actinomycosis. Diagnosis
History
The disease was originally discovered by Otto Bollinger (1843–1909) in 1870, and its name was coined by Sebastiano Rivolta (1832–1893) in 1884. The name refers to its grape-like granules (Gr. botryo = grapes) and the mistakenly implied  fungal etiology (Gr. mykes = fungus). In 1919 the bacterial origin of the infection was discovered. Notes
Concise Review of Veterinary Microbiology - Quinn and Markey 2003

External links
Essay on Pulmonary Botryomycosis
The cranial nerves affected are (from most common to least common) : VIII (cochlear component), VIII (vestibular component), V

Acoustic neuroma/vestibular schwannoma
Meningioma, a tumor of the meninges or membranes that surround the nerves passing through the CPA
Cerebellar astrocytoma, a malignant tumor of star-shaped glial cells called astrocytes in the cerebellum
Intracranial epidermoid cyst
Lipoma
Glomus jugulare associated with the glossopharyngeal nerve
Idiopathic hypertrophic pachymeningitis
IgG4-related hypertrophic pachymeningitis
CPA Metastases in cancer patients with inner ear symptoms (rare)

Diagnosis
Radiography
Subsequent to diagnosis of sensorineural hearing loss, and differential diagnosis of retrocochlear or neural etiologies,
radiological assessment of the CPA is performed to assess the presence of anatomical retrocochlear lesions. Traditional protocols
Before the advent of MRI, electronystagmography and Computed Tomography were employed for diagnosis of acoustic neuroma. Auditory brainstem response audiometry and adjunct tests
The auditory brainstem response (ABR) test gives information about the inner ear (cochlea) and nerve pathways for hearing via ongoing electrical activity in the brain measured by electrodes placed on the scalp. Five different waves (I to V) are measured for each ear. Each waveform represents specific anatomical points along the auditory neural pathway. Delays of one side relative to the other suggest a lesion in cranial nerve VIII between the ear and brainstem or in the brainstem itself. The most reliable indicator for acoustic neuromas from the ABR is the interaural latency differences in wave V: the latency in the impaired ear is prolonged. Different studies have indicated the sensitivity of ABR for detection of acoustic neuromas 1cm or larger to be between 90 and 95%. Sensitivity for neuromas smaller than 1cm are 63-77%.