Potentially life-threatening emergency
Rocky Mountain spotted fever in Child
Alerts and Notices
Synopsis
The disease is spread by ticks (the American dog and Rocky Mountain ticks) via a tick bite or by crushing a tick and transmitting its fecal matter via a mucosal surface (eg, rubbing the eyes). RMSF occurs over a wide distribution throughout the contiguous United States, but cases are most commonly reported from Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee. Over 90% of cases occur during April through September. The disease is more frequent in males; age-specific incidence is highest in children. Overall, the incidence of RMSF has been increasing from 300-800 to 2000 cases per year, but the case fatality rates (at least in the United States) have been decreasing (attributed to enhanced recognition and early treatment).
Early clinical manifestations of RMSF include high fever, severe headache, myalgia, and nausea and vomiting. Later manifestations include rash, photophobia, confusion, ataxia, seizures, cough, dyspnea, arrhythmias, jaundice, and severe abdominal pain. Thrombocytopenia or hyponatremia may be seen. A serious complication of RMSF is rhabdomyolysis. Long-term sequelae include central nervous system deficits and amputations.
Codes
ICD10CM:A77.0 – Spotted fever due to Rickettsia rickettsii
SNOMEDCT:
186772009 – Rocky Mountain spotted fever
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Meningococcemia typically occurs in the late winter to early spring with fever and rash appearing within 24 hours of infection. There is also marked lymphadenopathy.
- Measles typically occurs in the winter to spring and has associated symptoms of cough, coryza, conjunctivitis, and Koplik spots.
- Enteroviral infections typically occur in the summer to fall. The fever and rash often appear together. Sick contacts are common.
- Dengue fever, also known as "breakbone fever," has severe arthralgias.
- Vasculitis is marked by palpable purpura rather than petechiae.
- Drug eruptions (exanthematous, purpuric) will have a history of exposure.
- Secondary syphilis can also present with a palm and sole rash; occasionally, the rash imparts a rust-colored hue.
- Gonococcemia may present with asymmetric monoarticular arthritis and a pustular or petechial rash.
- Viral or bacterial enterocolitis presents with nausea and vomiting.
- Acute surgical abdomen has severe abdominal pain.
- Hepatitis presents with jaundice.
- Meningitis has prominent neurological signs.
- Idiopathic thrombocytopenic purpura (ITP) presents with a petechial rash.
- Thrombotic thrombocytopenic purpura (TTP) is characterized by fever, anemia, thrombocytopenia, renal impairment, and neurological deficits.
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Management Pearls
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Therapy
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References
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Last Reviewed:08/14/2018
Last Updated:08/16/2018
Last Updated:08/16/2018
Potentially life-threatening emergency
Rocky Mountain spotted fever in Child