Can allergy casue hyperventilation? i allergic to mold especially worse in rainny day and humid environments. i feel a difficulty to breath.

Possibly : Allergy per se does not cause hyperventilation which however may occur when there is an upper or lower airway obstruction for some people. You should consult an allergist re. Your mold allergies especially if there is a water issue in your home. You need to fix the water issue or move out of the place since even more serious health issues may occur otherwise.

Rapid breathing: Difficulty in breathing or rapid breathing is misinterpreted as hyperventilation, all due to tightened up airways when exposed to molds u r allergic to, in rainy days "fusarium" a type of mold is usually present in abundance and has a sweet smell, some people are allergic to such mold which causes their airway passages to react and tighten up, u need to be evaluated by an allergist.