Spotted fever due to Rickettsia rickettsii

This code identifies Rocky Mountain Spotted Fever (RMSF), a severe tick-borne illness caused by the bacterium Rickettsia rickettsii. It is characterized by fever, headache, and a distinctive rash that often begins on the extremities and spreads to the trunk.

Assign this code when documentation confirms a diagnosis of Rocky Mountain Spotted Fever. This typically requires laboratory confirmation of Rickettsia rickettsii infection, such as serology or PCR, in conjunction with characteristic clinical signs and symptoms.

• Ensure documentation specifies Rickettsia rickettsii as the causative agent to differentiate from other spotted fevers.
• Do not confuse with other rickettsial infections, such as typhus, which have different ICD-10-CM codes.
• Consider co-morbidities or complications of RMSF, such as neurological involvement or organ damage, and code them separately if documented.