Cogan's syndrome and treatment-resistant psychosis

To the Editor

Cogan’s syndrome (CS) is a rare autoimmune disease, characterised by ocular disease, interstitial keratitis and vestibuloauditory dysfunction with 10% developing visual impairment and 52% developing hearing loss, which is typically bilateral and progressive (Gluth et al., 2006).

Mr K is a 46-year-old man diagnosed with CS in 2011 after developing anterior uveitis and hearing loss. He was treated with Prednisolone, topical corticosteroids and the immunosuppressant mycophenolate but still developed bilateral sensorineural hearing loss and significant visual impairment. Mr K was diagnosed with autism and intellectual disability as a child. Since 1991, Mr K experienced psychotic episodes consisting of ‘bad thoughts’, obsessional behaviours, images of Jesus in his mind together with non-specific paranoid ideation. He maintained remission on a combination of Olanzapine and Flupenthixol Decanoate. However, following CS onset, his psychosis progressed accompanied by new-onset auditory and visual hallucinations with more persistent and severe persecutory delusions. Mr K was subsequently commenced on Clozapine, and this led to significant improvement with residual visual and auditory hallucinations.