Thanks for your question on Healthcare Magic.
I can understand your concern.
By your history and description, possibility of
allergic rhinitis is more.
You are allergic to something from the environment of Hong Kong. And this gives recurrent symptoms.
So in my opinion, you should consult good allergist and first diagnose yourself.
You will mostly improve with intranasal spray containing steroids (
fluticasone) and oral combination of antihistamine (levocetrizine or
fexofenadine) and anti allergic (
montelukast).
Steam inhalation 4-5 times a day is also beneficial.
Drink plenty of fluids orally and keep your self hydrated.
For boosting immunity you should take annual
influenza vaccine. In diet you should take natural anti oxidants like turmeric, honey, green tea etc.
All these will boost your immunity.
So consult good allergist and discuss all these.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.