Fever pattern is helpful to diagnose the associated infection in Acute Rheumatic Fever. The gold standard for diagnosis of GAS (Group A streptococcus) pharyngitis is bacterial culture. However, throat culture takes 24 - 48 hours and requires culture facilities. Therefore, culture tests are difficult to use in primary care practice. To compensate for these shortcomings, a rapid antigen detection test (RADT) was developed to detect GAS within a few minutes without the need of laboratory facilities. The Korean upper respiratory tract infection guideline recommends that the RADT to be performed in patients with modfied Centor score of 3 or above. A rapid slide agglutination test (streptozyme, Carter Wallace test) that looks at antibodies against several (five) streptococcal extracellular antigens and it is thought to improve the detection of streptococcal infection. The coexistence of acute rheumatic fever with malarial infection is uncommon. Relapsing pattern of fever is the short febrile periods occurring between one or several days of normal temperature. Malaria, in particular that caused by infection with plasmodium vivax, produces relapsing fever at 48 hrs interval. The exact mechanism for acute rheumatic fever remains unexplained and ‘molecular mimicry’ appears to be most likely. Similarly for coexistence of acute rheumatic fever with malarial infection remains unexplained and related to ‘altered immune status’, particularly with P. vivax infection which may be related to specific duffy blood group antigen.