II. Definition

  1. Mosquito-borne alphavirus named for "To walk bent over" in Tanzanian

III. Pathophysiology

  1. Mosquito borne alphavirus
  2. Regions
    1. Originally described in East Africa in 1950s
    2. Caribbean
    3. Central America
  3. Vectors
    1. Mosquito vectors
      1. Aedes aegypti
      2. Asian tiger Mosquito

IV. Symptoms

  1. Symptoms follow 2-4 days (up to 12 days) of asymptomatic Incubation Period
  2. Fever with abrupt onset
    1. Fever may be absent
    2. Undulating fever may occur (similar to Dengue Fever)
  3. Pharyngitis
  4. Back pain
  5. Headache
  6. Polyarthralgias, especially small joints (e.g. ankles, wrists, toes, fingers)
    1. May be severe, similar to Dengue Fever

V. Signs

  1. Rash (present in 50% of patients)
    1. Pruritic rash
    2. Starts with Flushing and then maculopapular rash involving trunk and extremities
    3. Desquamation of palms and soles
    4. Bullous Facial Edema
  2. Other uncommon presentations
    1. Meningoencephalitis (children)
    2. Ocular changes

VI. Labs

  1. Complete Blood Count
    1. Lymphocytosis (or often normal WBC Count)
    2. Thrombocytopenia
  2. Chikungunya IgM
    1. May be falsely negative in first 2 weeks

VII. Differential Diagnosis

VIII. Management

  1. Supportive care
  2. Avoid Aspirin and NSAIDs (until Dengue is excluded)

XII. References

  1. Martin (2010) Park Nicollet Primary Care Update CME, Minneapolis, MN
  2. Huntington (2016) Am Fam Physician 94(7): 551-7 [PubMed]

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