Chronic hives triggered by dust mites

Hi,

I've got hives since 2 months ago after recovered from a sore throat without fever. Have seen few doctors and done some test.
I wish to share my findings and hopefully somebody with similar experience or is knowledgeable can share some opinions

First i got my blood tested with ImmunoCap & found that my total IGE is elevated to 160 kul (normal is < 100) and
dust mite allergy of class 3 (severe). I've had rhinitis since i am 15 and was known to be trigger in dusty enviroment.
Seems like now the dust mites also trigger my hives! Basically my hives are pretty minimal while i am at home but
whenever i went to dusty environments like places with cluttered stuff, books, old fur sofas, car filled with fur toys my hives will go crazy
and i'll be cover up with hives start from my bicep to elbow then to legs & knees. Then if i leave the place immediately and go back home
the hives will slowly reduced. Both me & the doctor thinks that dust mites are my major trigger but they should not be the cause of my
hives, though i read some online articles that for some people dust mites can be the causative factor for their hives which proven when
their hives were gone after immunotherapy. I've request to be on dust mite immunotherapy, the doctor recommend the allergy shot
instead of sub lingual as it is more effective.

Second, i've went to dental to check my minor bleeding gum which has been happening few months ago before i got hives. The bleeding
spot is near one of my front tooth where there is an extra tooth behind. After some checking by the dental, i've decided to have the extra
tooth remove. After the tooth is removed i was prescribed an antibiotic name Metronidazole for few days. What i experienced is that for
these few days on the antibiotics my hives were calm down very significantly, i could go to dusty places with no major break out but only a few
tiny spot of hives. Sadly few days after i finish the antibiotic my hives condition were back to normal.
This has puzzled me! Antibiotic should not have any effect on my hives unless there is an infection. I am suspecting that i have some hidden
infection causing my hives which were responding to the dental's antibiotic but the antibiotic is not strong enough to cure it.
Could that be!?

Has actually discussed with a ENT specialist, a Dermatologist & a Immunologist.
Both the ENT & Dermatologist doctor straight away told me it's not the antibiotic that helps but time.
They don't even try to reason why my hives were back to full force after the antibiotic were stop.
They prescribed anti histamines and that's it :(

Fortunately the Immunologist doctor were a lot more understanding and patient. He agree that i
should try another round of antibiotic before i start the immunotherapy. Though he didnt go into
detail on that. I'm wondering what kind of antibiotic can be prescribe without knowing where the infection is...