Rheumatic fever in a high incidence population: the importance of monoarthritis and low grade fever

Aims-To describe the clinical features of rheumatic fever and to assess the Jones criteria in a population and setting similar to that in many develop ing countries. Methods-The charts of 555 cases of confirmed acute rheumatic fever in 367 p atients (97% Aboriginal) and more than 200 possible rheumatic fever cases f rom the tropical "Top End" of Australia's Northern Territory were reviewed retrospectively. Results-Most clinical features were similar to classic descriptions. Howeve r, monoarthritis occurred in 17% of confirmed non-chorea cases and 35% of u nconfirmed cases, including up to 27, in whom the diagnosis was missed beca use monoarthritis is not a major manifestation. Only 71% and 25% of confirm ed non-chorea cases would have had fever using cut off values of 38 degrees C and 39 degreesC, respectively. In 17% of confirmed non-chorea cases, anti -DNase B titres were raised but antistreptolysin O titres were normal. Alth ough features of recurrences tended to correlate with initial episodes, the re were numerous exceptions. Conclusions-Monoarthritis and low grade fever are important manifestations of rheumatic fever in this population. Streptococcal serology results may s upport a possible role for pyoderma in rheumatic fever pathogenesis. When r ecurrences of rheumatic fever are common, the absence of carditis at the fi rst episode does not reliably predict the absence of carditis with recurren ces.