Lupus psychosis: an unusual cause of acute confusion presenting to acute medicine

A young lady was brought to the hospital by the police after they found her wandering in the streets far away from her home behaving oddly. At admission, she was confused and had various delusional thoughts accompanied by visual and auditory hallucinations. After she was identified and her old medical notes were retrieved, it was found that she had a diagnosis of systemic lupus erythematosus (SLE) previously for which she declined any treatment. MRI brain, CSF results and EEG were unremarkable. Laboratory results confirmed the diagnosis of SLE with low disease activity. Anti-RNP antibodies were positive alongside other common markers of SLE, which pointed towards a rare entity called lupus psychosis. She was started on immunosuppression with methylprednisolone and cyclophosphamide combined with antipsychotics. Following treatment, she improved significantly and is currently leading a normal life.