Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder 
characterized by a pentad consisting of thrombocytopenic, microangiopathic 
hemolytic anemia, renal dysfunction, neurological signs and fever. Coexistence 
of thrombotic thrombocytopenic purpura and Adult Onset Still's Disease (AOSD) is 
extremely rare. We report a case of 18 year old girl with AOSD who developed 
TTP. Neuroimaging of brain demonstrated white matter edema consistent with 
reversible posterior leukoencephalopathy syndrome (RPLS). Complete recovery 
occurred with prompt anti-hypertensive treatment and high dose immunoglobulin 
infusions (IVIg). Plasma exchange is the standard of care and the first line 
treatment for patient with TTP. We used IVIg alone in our case and this showed a 
gratifying response. Use of IVIG before considering plasmapharesis is 
justifiable or not requires randomized control clinical trials. This should 
determine the optimal therapeutic strategies for TTP.