CC: Dizziness, Shortness of Breath
HPI: This is a 60 yo obese male with no past medical history presenting with one week of dizziness and shortness of breath. He states that he has been feeling dizzy with standing and short of breath when walking just in his apartment. He does not have any chest pain, nausea, vomiting, orthopnea, or paroxysmal nocturnal dyspnea but does have subjective fevers at home. On review of systems he reports truncal rash that started a day or two ago. Social history is pertinent for working at the Mission shelter in Downtown Los Angeles. On exam, he is febrile to 40.8 with a HR of 110. He is tachypneic, diaphoretic with dry mucous membranes. On repeated checks, patient has waxing and waning mental status. He has no murmurs, his lungs are clear, and his abdomen soft. The rash is macular and blanchable overlying his anterior chest with no palmar or sole involvement. Labs are pertinent for a Cr of 1.5 with FeNa 0.2%. UA does show some WBCs and RBCs but complements are normal and serologies negative. Transaminases are elevated: AST 175, ALT 133 with intact liver function. There is also a thrombocytopenia to 113. LP shows normal protein and glucose with 0 WBC. Blood cultures remain negative. Rickettsial serologies are pursued and R typhi IgG and IgM are positive with titers of 1:256 and patient is diagnosed with Murine Typhus.
Morning Report Pearls:
Relative bradycardia is a unique finding in certain infections, mainly intracellular organisms. Defining relative bradycardia requires a patient to have a fever of >102, be in sinus rhythm, and not be on beta blockers. If their heart rate does not correspond to the normal rate seen with the degree of fever then it can be termed a relative bradycardia.
T 102 should have a HR >110
T 103 should have a HR >120
T 104 should have a HR >130
T 105 should have a HR >140
T 106 should have a HR >150
Infectious Etiologies that have Relative Bradycardia:
- Viral: Dengue fever, Yellow fever
- Bacterial: Brucellosis, Legionella, Tularemia, Mycoplasma, Typhoid, Leptospirosis, RMSF, Typhus, Q fever, Psittacosis
Non-infectious Etiologies that have Relative Bradycardia:
- Central Fever
- Drug Fever
- Tumor fever
Consider rickettsial diseases when a patient has high fevers, headache, transaminase elevation, thrombocytopenia, and rash. Because we reside in Los Angeles, always have to consider Murine Typhus specifically (only really seen in California and Texas).