Hi.. Thanks for the query.. Salty taste in mouth can be due to a number of causes but if you also have symptoms of flu it can be probably due to post nasal drip or infection in mouth.. At times the tongue becomes irritated due to infections making it hypersensitive.. Other common causes are long standing dehydration, dry mouth, side effect of medications etc. An autoimmune disease known as Sjogrens syndrome is also seen to cause salty taste in mouth.. Nothing to worry, consult an Oral Physician and get evaluated and after a thorough clinical examination and investigations [if required], treatment can be planned.. As of now drink plenty of water and chew sugar free chewing gums. Hope this helps.. Regards.