Acute encephalitis syndrome with the cause hidden in plain sight – A case series

Abstract

Acute encephalitis syndrome (AES) is one of the important life-threatening presentations in children with a case fatality rate of 12.6%. The most common etiology in India is viral encephalitis. However, one of the emerging yet treatable causes is scrub typhus, which is endemic in many parts of India including Tamil Nadu and Puducherry. It is a vector borne disease which has myriad presentations, one among those being AES. This is a case series of four such cases noted over the first 6 months of 2022. All the patients presented with symptoms of fever and alteration of sensorium without any seizures. Examination revealed generalized lymphadenopathy, hepatosplenomegaly, and abnormal central nervous system findings. A thorough examination revealed the classical eschar in all the cases. Based on the examination findings, oral doxycycline was started in all the patients along with supportive treatment while awaiting results, which later revealed to be scrub ELISA positive. After 48 h, due to inadequate defervescence and improvement in sensorium, IV azithromycin was added in two patients and oral doxycycline was changed to injectable in other two patients. All of them recovered without any complications or sequelae. Early identification and initiation of appropriate antibiotics are essential for a positive outcome. In endemic areas, children with AES should be thoroughly examined for signs of scrub typhus including eschar. In our patients, parenteral doxycycline or azithromycin was found to be more effective than oral doxycycline in resolution of fever and neurological abnormalities. If AES is suspected to be due to scrub typhus, parenteral therapy may be preferred over oral.