I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

Consult your pediatrician to use medications

Yes. Your child needs to be put on leucovorin. But consult first.

Needs physical examination, how long symptoms are there and how many symptoms are there

Consult with Pediatrician physically for further evaluation and treatment

a positive FRAT test alone does not automatically mean that every child should receive leucovorin. The decision should be made by the child’s developmental pediatrician or pediatric neurologist after reviewing the complete clinical picture.

Do not self medicate the child. Consult a pediatrician nearby  first

Greetings A positive FRAT® indicates the presence of autoantibodies blocking folate transport to the brain. Leucovorin (folinic acid) can bypass this block, but you must consult your pediatrician to prescribe it. Common pediatric side effects include increased irritability, hyperactivity, or trouble sleeping. Other possible reactions include mild gastrointestinal upset, nausea, or allergic rashes

Kindly show once physically to nearby pediatrician