Question: What diagnosis code should I use for rhinorrhea? The only mention I find is 349.81, but that doesn't sound right. Nevada Subscriber Answer: You should report rhinorrhea -- otherwise known as a runny nose -- with 478.19 (Other diseases of nasal cavity and sinuses). This unspecified code describes -other diseases of nasal cavity and sinuses- including -rhinolith,- according to the code's inclusion entry in the 2007 ICD-9-CM Manual. Tool: Your instinct is correct regarding 349.81 ((Cerebrospinal fluid rhinorrhea)). CSF rhinorrhea results from a defect or injury to the skull that allows fluid to leak into the nasal passages -- a much more serious condition than a runny nose.