title: Atypical Rocky Mountain spotted fever with polyarticular arthritis.
abstract: BACKGROUND
  Rocky Mountain spotted fever (RMSF) is an acute, serious tick borne illness caused by Rickettsia rickettsi. Frequently, RMSF is manifested by headache, a typical rash and fever but atypical disease is common, making diagnosis difficult. Inflammatory arthritis as a manifestation is rare. The purpose of this study is to describe a patient with serologically proven RMSF who presented in an atypical manner with inflammatory arthritis of the small joints of the hands and to review the previously reported patients with rickettsial infection and inflammatory arthritis.
  
  
  METHODS
  An 18-year-old woman presented with a rash that began on the distal extremities and spread centrally, along with hand pain and swelling. She had tenderness and swelling of the metacarpophlangeal joints on examination in addition to an erythematosus macular rash and occasional fever.
  
  
  RESULTS
  Acute and convalescent serology demonstrated R rickettsi infection. She was successfully treated with doxycycline.
  
  
  CONCLUSIONS
  Inflammatory arthritis is a rare manifestation of RMSF or other rickettsial infection with 8 previously reported patients, only 1 of whom had RMSF. Physician must have a high index of suspicion for RMSF because of atypical presentations.
authors.affiliation: Department of Medicine (MAC, RHS), University of Oklahoma Health Sciences Center; Arthritis & Clinical Immunology Program (RHS), Oklahoma Medical Research Foundation; and Medical Service (RHS), Department of Veterans Affairs Medical Center, Oklahoma City, Oklahoma.
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Chaudhry
authors.forename: Robert Hal
authors.initials: RH
authors.lastname: Scofield
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001168:Arthritis / Q000175:diagnosis* / Q000382:microbiology*; D003937:Diagnosis, Differential; D018450:Disease Progression; D004318:Doxycycline / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008662:Metacarpophalangeal Joint / Q000473:pathology; D012373:Rocky Mountain Spotted Fever / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline