Rickettsialpox in Adult
The disease has been identified in urban areas of the United States as well as South Korea, South Africa, and parts of Russia.
The bite follows a 10- to 24-day incubation period, after which an eschar at the site of the mite bite appears (1 of 7 patients will have multiple eschars), followed by fever, nontender regional lymphadenopathy, headache, photophobia, and anorexia 2 to 7 days later. The clinical course of the disease lasts 2 to 3 weeks and is generally self-limited. A persistent headache and lassitude can last for weeks following the acute illness. No deaths clearly attributable to rickettsialpox have been reported to date.
A79.1 – Rickettsialpox due to Rickettsia akari
75096007 – Rickettsialpox
Differential Diagnosis & Pitfalls
- Other rickettsioses with eschar that are typically acquired outside the United States (eg, tick typhus, Mediterranean spotted fever, and scrub typhus).
- Varicella lesions (primary or post-vaccination) evolve in different stages (ie, they do not appear uniform) and often scar, whereas rickettsialpox lesions do not.
- Eczema herpeticum
- Eczema vaccinatum
- Enteroviral infections
- Infectious mononucleosis
- Cutaneous anthrax
- Spider bite
- Acute meningococcemia (early)
- The lesions of smallpox are deeper and larger and are prominent on the face (this has been eradicated but remains a bioterrorism threat).