Introduction This case report explores a possible undifferentiated autoimmune neuroinflammatory illness presenting with recurrent fevers, abdominal pain, hypersomnolence and sleep attacks with low cerebrospinal fluid (CSF) hypocretin, and a partial response to anakinra, a human interleukin 1 receptor antagonist.

Case Presentation A 19 year old female presented with 5 years of abdominal pain and fatigue with no clear aetiology identified following extensive investigation. She subsequently was found to have recurrent fevers to 38°C, an intermittent fine, macular rash and sudden sleeping at inappropriate times. Her brain MRI was normal and (CSF) showed normal protein and no white cells, but a low hypocretin level (<200 units). Further investigations including whole exome sequencing, gastrointestinal, autoimmune and metabolic assessments, yielded limited findings. Previous therapy with colchicine had been ineffective.

Management and Outcome For a presumptive diagnosis of an undifferentiated autoinflammatory disorder, she was received prednisolone 10 mg daily for 4 weeks with no benefit. She then initiated anakinra, which improved in rash and sleep attacks. Despite initially controlling her recurrent fevers for a period of four weeks, this symptom ultimately recurred, with ongoing abdominal pain.

Discussion Low levels of hypocretin in the CSF has been associated with narcolepsy type 1 and has thought to been associated with an undefined autoimmune mechanism. It is hypothesised that her hypothalamic orexin has been altered due to these inflammatory changes leading to body temperature dysregulation and sleep disorder. Interestingly the hypersomnolence appear to have improved with anakinra, a therapy not typically used in narcolepsy.