Grass pollen allergyJ30.- J45.-

Grass pollen is one of the most common sources of allergens, along with tree pollen. Both pollen groups release large amounts of allergenically active portoins and glycoproteins on contact with water, which can cause allergic symptoms on the exposed mucous membranes.

A grass pollen allergy is generally understood to be a type I sensitisation to grass pollen.

Most of the allergenic grasses in Europe belong to the botanical family of sweet grasses (Poaceae) and within this family, in turn, to the subfamily of Poideae (= grass-like, from Poa, Greek: grass). This family is represented worldwide, comprises about 150 genera with about 3300 species. The sweet grasses are closely related to each other in terms of their structural allergenicity, so that broad cross-reactivities are present in tests with allergen extracts. Only molecular allergy diagnostics, also called "component resolved diagnostic" or CRD, allows the exact identification of the responsible allergens. This enables the investigator to make the important decision in polysensitized patients between true sensitization and cross-reactivity by pollen allergens (e.g. profilins, polcalcins) that occur together in a grass family. This differentiation enables an optimal choice to be made for a specific immunotherapy.

From the family of sweet grasses and the structurally closely related allergy-relevant subfamily of the Pooideae , the species occurring in the temperate climate zones (selection):

• Cockle Grass
• Ryegrass
• Cockle grass
• bluegrass
• Oats
• Scented Grass
• Timothy grass
• Rye
• Wheat

Other grasses from the group of sweet grasses such as dog grass, rice, reed grass, bahia grass, corn belong to other subfamilies and are more common in the hot and tropical zones.

• Airport oats (Windhafer): The pollen very often causes allergies. Flight time: June to August. Size: 36-44 µm. Cross allergies are possible with all other grass pollen.
• Barley: Low pollen count. Flowering time: July to September. Allergies are very rare. The pollen are 34-55 µm in size. Some grass pollen allergy sufferers also react to barley.
• Glasswort: Allergies are rare in Germany, but frequent in Mediterranean countries. The pollen fly between June and September. Size: 12-17 µm. Possible cross-allergy to nettle pollen.
• Oatmeal (also: false oat, meadow oat): Intensive pollen flight between June and July. Allergies are very common. The pollen size is 27-44 µm. There are cross allergies with all other grass pollen.
• Oats: self-pollinator. No significant pollen flight. Flowering time: July and August. Cross-allergies exist against grass pollen.
• Honey grass: Pollen is highly sensitizing. Flight time: June and July. Size: 25-34 µm. Allergens of honey grass pollen are the proteins Hol l 1 and l 5. Cross-allergies: to pollen of all other grasses.
• Bermudagrass: pollen is highly sensitizing. Flight time: May to August. Size of pollen: 18-32 µm. The major allergen is Cyn p 1 from the grass group 1 family.
• Meadowgrass: The pollen is one of the most common allergens among grasses. Flowering time: May to August. Size of pollen: 23-42 µm. Allergens of the grass pollen are the proteins Dac g 1 to g 3 and g 5. Cross-allergies: to pollen of all other grasses.
• timothy grass: see timothy grass
• Ryegrass: Allergies to ryegrass pollen are common. The pollen fly between May and July.
• Maize: Rare allergies. The pollen does not fly far. Maize flowers between July and September. Size of the pollen: 52-142 µm. Cross allergies with the pollen of all other grasses are possible.
• Cockle: pollen is one of the most common grass allergens. The pollen fly from May to July. Pollen size: 20-26 µm. The main allergen is the protein Poa p1. Cross allergies occur with the pollen of all other grasses.
• Rye: One of the most common and aggressive allergens. The pollen fly in May and June. Cross-allergies with all other grass pollen are possible.
• Scented grass (golden grass, lavender grass): Allergies are very common. The pollen fly between April and June. Size: 23-39 µm. Cross allergies are possible with all other grass pollen.
• Fescue: pollen very often causes allergic reactions. Flowering time: June and July. Size of pollen: 25-35 µm. Cross-allergies with the pollen of all other grasses are possible.
• Ostrich grass: pollen often causes allergic reactions. Flight time: June and July. Size: 25-35 µm.
• Wheat: Only low pollen count (wheat usually pollinates its own flowers). Allergies are very rare. Flowering time: July and August.
• Timothy grass (Timothy grass, fire grass): Common allergies. The pollen fly between May and September: size: 30-45 µm. Allergens of timothy grass pollen are the proteins Phl p 1 to p 13, Phl p 1 and Phl p 5 are major allergens of timothy grass. Cross allergies with all other grass pollen are possible.

In Europe about 10-17% of people suffer from grass pollen allergy.

Despite botanical similarity and of different description: grass pollen allergy sufferers usually do not have any problems when consuming gear products.