Is it true that, flu like symptoms and or sore throat sometimes be just a symptoms of coming of asthma, while having no virul/bacterial cause?

Influenxa. What do you mean by flu-like symptoms? If you are having fever, chills, muscle aches and upper respiratory tract congestion with or without GI symptoms you probably have one of several viruses that can cause a flu-like illness. Cough can suggest asthma onset but this more common in children. Your symptoms are more likely viral infection.