Case Presentation: A 63-year-old Hispanic man from Mexico, with a history of hypertension and obesity, presented in September to an outside hospital with high fevers. He worked as a truck driver primarily in Arizona. He had a witnessed seizure and developed persistent altered mental status. The patient rapidly decompensated into septic shock requiring vasopressors, and was transferred to our institution for further care. He was intubated for airway protection, was started on antiepileptics, and received empiric antiviral and antibiotic treatment for a presumed meningoencephalitis. Physical examination was notable for asymmetric pupils with the right larger than the left with bilateral sluggish reactivity to light, coarse breath sounds throughout, and a mild petechial rash noted on the patient’s stomach and lower extremities bilaterally. The patient was also noted to have elevated liver enzymes (AST 160 units/L, ALT 130 units/L) and thrombocytopenia (platelets 78,000/mm ). A lumbar puncture was unremarkable. Rocky Mountain Spotted Fever (RMSF) serology returned positive for IgG. RMSF IgM was sent out to an outside laboratory. The patient was presumptively diagnosed with RMSF. He improved on empiric therapy, with doxycycline, which was deescalated to a 10-day course. He returned to his baseline normal mental status, remained seizure free, and was discharged in stable condition with continuing physical therapy.
Discussion: Rocky Mountain Spotted Fever (RMSF), a tickborne disease, is characterized by a centripetal blanching erythematous rash transitions from a macular to petechial appearance. While the rash is present in up to 90% of cases, fewer than half of the patients develop it within the first three days of illness. Delay in appropriate diagnosis and treatment beyond five days has been associated with a threefold increase in mortality in one series, necessitating recognition of secondary/atypical features. Our patient’s presenting symptom, seizure, is relatively uncommon for RMSF. Neurological symptoms occur in roughly one-third of RMSF patients. While just over 5% can present with a seizure as our patient did. Other neurological symptoms can include a headache, meningismus, amnesia, confusion, or focal deficits. RMSF most often presents with nonspecific symptoms including fever, headache, nausea, myalgias, arthralgias, and malaise. Associated lab abnormalities include thrombocytopenia and elevated transaminases as noted in our patient. Other lab abnormalities include hyponatremia, azotemia, and PT and PTT prolongation. Geographic and seasonal risk factors are also vital to consider. RMSF is endemic to Central America, Canada, Mexico, and parts of South America. It is most common within the south and the southeastern United States with North Carolina, Oklahoma, Arkansas, Tennessee, and Missouri accounting for over 60% of cases. Incidence is highest in the early summer in most areas. However within the state of Arizona incidence peaks in July through September. Our patient presented with an uncommon chief complaint to an uncommon locale, but in hindsight, his case fits many classic features of RMSF, a lesson that first impressions do not always tell the whole tale.
Conclusions: While RMSF is well known for its hallmark blanching erythematous rash, it frequently presents several days into the infection. Recognizing the constellation of other atypical features of RMSF can be helpful towards timely diagnosis and prompt initiation of treatment.