DISCUSSION

ANCA vasculitis is a rare disease characterized by antibodies against neutrophil and monocyte lysosomal enzymes which include myeloperoxidase and proteinase 3 (1). The pathogenesis for ANCA vasculitis involves numerous immune cells; B lymphocytes produce ANCA, with BAFF encouraging the autoimmunity with B cells, plasma blasts and plasma cells (2). These activate neutrophils and results in generation of C5a via the complete pathway, causing further activation of neutrophils(3). Activated neutrophils results in propagation of tissue damage and vascular inflammation. The main target organs in granulomatous polyangiitis include the ear, nose throat and upper respiratory tract, glomerulonephritis of the kidney and the lungs. Localized disease manifestation can include the nose (rhinorrhea, nasal crusts, septal perforation) and ear (otitis media, hearing loss, sensorineural deficits). The diagnosis of vasculitis from localized disease manifestation can be difficult (1). Otological manifestations as seen in our patient as otitis media is very uncommon as an initial presentation. Granulomatosis polyangiitis can affect the external, inner and middle ear. Otitis media is caused by granulomatous process that occurs in the middle ear and can also involve the mastoid cavity (4). In many cases it is difficult to differentiate from otitis media and granulomatous polyangiitis. The otological symptoms occur insidiously and making early diagnosis essential as one has the risk of developing profound hearing loss and the systemic disease can be fatal, hence early diagnosis has become paramount importance to improve prognosis (5). The ontological symptoms tend to progress despite myringotomy or mastoidectomy (1). The above patient had undergone an mastoidectomy twice with progression of symptoms. Most cases of otitis media associated vasculitis (OMAAV) present with facial nerve palsy (6). Neurological manifestations can occur but are rare in granulomatous polyangiitis. They may present with cranial nerve palsy, peripheral neuropathy cerebrovascular events or cerebritis (7). Three main histological frameworks have been identified: CNS vasculitis of the small vessels of the brain and spinal cord, granuloma invasion from extracranial site, isolated intracranial granulation(8). The unusual manifestation in the aforementioned patient was the presentation of otitis media with trigeminal neuralgia and her disease progressed to peripheral length dependent neuropathy and there after a pontine infarct. Peripheral neuropathy is the most common neurological manifestation as per De Groot K et la; he has a cohort of 128 patients with GPA 46% of the patients had peripheral neuropathy and 4% had cranial nerve palsies (9). The unusual presentation we had with our patient is the presentation with chronic otitis media and trigeminal neuralgia, most patient with otitis media tend to present with facial never palsies as illustrated by Yasuaki Harabuchi et la facial nerve palsy can be caused by inflammatory granulation that spread through the facial canal, this is not uncommon with Otitis media associated ANCA vasculitis (5). Cerebral Vascular accidents is also an uncommon manifestation of GPA though can occur, De luna et al had 35 patients in her cohort of study all of them underwent an MRI of the brain and 43 % of patients had either ischemic or hemorrhagic change in the blood vessels (8). ANCA vasculitis has a high rate of mortality when not diagnosed efficiently, the prevalence and incidence of ANCA vasculitis low in Africa and this can be secondary to having low resource centers to carry out tests for confirmation (10). It is important to treat as early once the symptoms manifest though many patient that present with otitis media miss the early window on treatment and fall in the curve of high mortality rate. Treatment for ANCA vasculitis is induction of remission via high dose steroids at 1mg/kg/day, where they normally pulse with steroids for two to three days(2). Addition of cyclophosphamide tends to improve the remission time in patient with ANCA vasculitis, rituximab and plasma exchange are other possibilities for treatment as well (2). Otological symptoms and CNS symptoms are rare complications but can present as atypical symptoms as in our case, it is essential to identify these cases early to prevent mortality rates as early treatment is the key to survival and remission.