Hazel allergy

Hazel allergy (Corylus) is one of the earliest spring allergens in Croatia. Hazel pollen is already airborne in January and flowers through March, making it the 'first herald' of the allergy season. Hazel is cross-reactive with birch and other Betulaceae allergens, so people allergic to birch often react to hazel as well.

Symptoms of hazel allergy are similar to those of birch - sneezing, a runny nose, watery eyes, an itchy palate and throat. In sensitive people, oral allergy syndrome can also occur after eating raw hazelnuts, along with reactions to apple, pear or cherry. Symptoms usually start in January or February, well before the main birch season.

The hazel season lasts from January to March, peaking in February. Warm winter days can trigger earlier flowering - hazel is very sensitive to temperature and may even start flowering in December in warm regions. Flowering usually ends by mid-March, when birch takes over.

Hazel is widespread throughout Croatia, but is most often recorded in the continental part (Zagreb, Slavonia, Zagorje). In Mediterranean Croatia and Istria the season starts earlier and lasts shorter.

Practically the same measures as for birch - windows closed at dawn and in the morning, HEPA filters, showering after coming home. If you are allergic to hazel, it is very likely you will also be allergic to birch - consider starting treatment early (as soon as December).

Hazel pollen cross-reacts with birch, alder and hornbeam (the PR-10 protein), as well as with raw hazelnuts, apple and peach.

Other allergens