There was a time when Allergist’s used to test hundreds of allergens called panels. As gradually science is developing, concept of cross reaction and with availability of community data the list of allergens is getting short.
Doctors who used to test for 220 allergens are now going for less than 40 allergens. Those who are more confident or have pin pointed the allergen by detailed history go for less than 10!
So, the list of allergens to be tested depends on your history, symptoms, frequency like whether perennial or seasonal, indoor or outdoor morning or evening, geographical location etc.
some allergens like dust mites are perennial, while pollens are seasonal. Pollen calendar helps in relating your symptoms with different pollens.