I work with two extremely prominent otologoists in the operating room in the San Francisco Bay area. They are often featured on "Good Morning America" and have heard them discuss vertigo on many occasions.
The organ of balance, located in your inner ear, is the vestibular labyrinth. It includes loop-shaped structures that contain fluid and fine, hair-like sensors that monitor the rotation of your head. These canals all attach to the utricle, which contains tiny granules or crystals of calcium carbonate. These particles are attached to sensors that help detect gravity and back-and-forth motion.
Vertigo occurs when the particles within the labyrinth loosen and float in the fluid. In certain positions they can irritate the nerve endings associated with balance, giving a false signal of movement and causing a brief sensation of spinning.
Vertigo most often is a result of aging .However, sometimes no cause can be determined
In your case the attack may be viral and coincidental that it occurs at these times.
If the canalith repositioning procedure isn't effective, your doctor may recommend a surgical procedure in which a bone plug is used to block the portion of your inner ear that is causing dizziness. The plug prevents the floating particles in your ear canal from moving. This success rate for canal plugging surgery is about 90 percent.
Blood tests (in vitro allergen-specific IgE antibody tests) are useful for those patients that cannot undergo skin testing, Often blood testing is performed in a child to obtain a a baseline indication if allergies are present. . Although blood tests are not as accurate as skin tests, and they're not performed as often because they are less sensitive and are more expensive. If you want to an accurate diagnosis as to cause of allergies you need the skin testing to identifiy the specific substances that trigger your allergies which could identify the if allergy or coincidence in your vertigo.