Tree pollen

• Birch: particularly aggressive allergens. Most frequent tree pollen sensitization in Germany. The pollen fly from April to May. Size: 16-31 µm. The most important allergen of birch is Bet v 1. Cross allergies: to pollen of alder, hazel, oak, red beech, hornbeam and sweet chestnut but also to apples, aniseed, apricots, avocados, bananas, basil, pears, chili pepper, cashew nuts, dill, fennel, Hazelnuts, carrots, potatoes, cherries, kiwis, coriander, cumin, lovage, lychees, almonds, marjoram, mangoes, oregano, peaches, peppermint, plums, pistachios, celery, tomatoes and thyme.
• Beech (Carpinus betulus = hornbeam) Allergies are rare. The pollen fly from April to May and grow to a size of 45-50 µm. The marker is Car p 1. cross allergies: against pollen of birch, oak, alder and hazel.
• Oak: Allergies are rare. The pollen fly from April to May. The pollen grains are 16-37 µm in size. The main allergen of oak pollen is the protein Que a 1. Cross-allergies: to pollen of birch, beech, alder and hazel.
• Alder: frequent sensitization. The pollen is considered very aggressive. They fly from February to April. Size: 14-35 µm. The main allergen of alder pollen is the protein Aln g 1st cross allergy: to pollen of birch, beech, oak, hazel.
• Ash, common: rare allergies; if there are sensitizations, they are usually severe allergic reactions. The pollen fly in March and April. Size: 18-26 µm. The main allergen is Fra e 1. cross allergies: to pollen of olive tree, lilac, privet and forsythia.
• Hornbeam: rare allergies; the pollen fly in April and May. Size: 22-36 µm. The main allergen of hornbeam pollen is the protein Car b 1. Cross-allergies: to pollen of birch, hazel and alder.
• Hazelnut: second most common allergen among tree pollen. Hazelnut pollen allergy is sometimes already noticeable in January. The pollen fly from January to March. Size: 8-32 µm. The main allergen of hazel pollen is the protein Cor a. Cross-allergies: to pollen of birch, alder, beech.
• Chestnut (Horse Chestnut): insect-pollinated plants; pollen is not transmitted by wind. Allergies to chestnut blossoms are rare. Chestnut blossoms between April and June. Pollen size: 15-35 µm. Cross-allergies are not known.
• Pine: most common allergen among all conifer pollen. Sensitisation is rather rare. Pollen season: May and June. Allergies to pine pollen only occur in combination with other sensitisations.
• Linden tree: Insect- and wind-pollinated plants. The pollen is only present in low concentrations. Rare allergies. Flowering time: June and July. Pollen size: 18-37 µm. Cross-allergies are not known.
• Olive: Pollen sensitization is not present in Germany. Allergy widespread in the Mediterranean region. The pollen fly between April and June. Size: 17-24 µm. Main allergens: Ole e 1 to e 6. Cross allergies: to pollen of ash, privet, lilac, pineapple and horseradish.
• Black poplar: pollen sensitisations are rare. Flowering time: March and April. Size: 25-32 µm. Cross allergies are not known.
• Elm: Allergies are very rare; usually only as a side effect with other sensitisations. The pollen fly in March and April. Size: 28-38 µm.
• Willow: Insect-pollinated plants. Rare allergies. Flowering time: March to April. Size of pollen: 16-28 µm. Cross allergies are not known.

In contrast to grass pollen, allergenic tree pollen comes from different plant families distributed in very different geographical regions.