Southern tick-associated rash illness

Background

Amblyomma americanum

• Abbreviation: STARI
• Transmitted by lone star tick (Amblyomma americanum)
  • female tick has single white dot or "lone star" on its back, aggressive feeders
• May be caused by spirochete Borrelia lonestari
• Midwest and Mid-Atlantic states

Clinical Features

"Bull's-eye" STARI rash

• Resembles Lyme disease in rash, constitutional symptoms, time course
• May have delayed anaphylaxis (3-6h) to red meat from IgE Ab to glycoprotein in meat of mammals, with negative allergy skin test

Differential Diagnosis

Tick Borne Illnesses

• Babesiosis
• Colorado tick fever
• Ehrlichiosis
• Heartland virus
• Lyme
• Murine typhus
• Rocky mountain spotted fever
• Southern tick-associated rash illness (STARI)
• Tick paralysis
• Tularemia

Evaluation

• No testing available

Management

• 10 days of doxycycline or amoxicillin
• No evidence this is beneficial, but commonly given

Disposition

• Home

See Also

• Rashes

References

• Hall J, Khan Sajid Small Bugs with Big Bites, EM Resident Oct/Nov 2014 Vol 4:5; 10
• http://www.cdc.gov/stari/symptoms/index.html