Thanks forposting your query.
White coated tounge may be due to leukoplakia
, oral thrush
and during tyhpoid fever.
You should consult with ENT surgeon and physician and go for widal test
After prolonged antibiotic course, candida albicans fungus which is a nromal commensal of our body may proliferate.
You should try to maintain normal commensal floraa of your body after discussion with physcian.
If all things appears to be normal, then you should consult with dermatologist
Dr. Mayank Bhargava