Allergic rhinitis region to region; in general, the tiny, hardly visible pollens of wind-pollinated plants are the predominant cause. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include: Allergic rhinitis may also be caused by allergy to Balsam of Peru, which is in various fragrances and other products. Allergy testing may reveal the specific allergens to which an individual is sensitive. Skin testing is the most common method of allergy testing. This may include a patch test to determine if a particular substance is causing the rhinitis, or
Allergic conjunctivitis injury. There are four classes of selectin blocking agents: (i) carbohydrate based inhibitors targeting all P-, E-, and L-selectins, (ii) antihuman selectin antibodies, (iii) a recombinant truncated form of PSGL-1 immunoglobulin fusion protein, and (iv) small-molecule inhibitors of selectins. Most selectin blockers have failed phase II/III clinical trials, or the studies were ceased due to their unfavorable pharmacokinetics or prohibitive cost. Sphingolipids, present in yeast like "Saccharomyces cerevisiae" and plants, have also shown mitigative effects in animal models of gene knockout mice. Allergic conjunctivitis occurs more frequently among those with allergic conditions, with the symptoms having a seasonal correlation. Allergic