Alder (Alnus) is as a rule the first species whose pollen reaches the air in North Macedonia. It flowers at the end of winter, often before anything else has leafed out, so the trouble it causes is regularly mistaken for a cold — the "winter cold that will not go away" in February is, in allergy sufferers, very often a reaction to alder pollen.
What alder is and where it grows
Alder is a deciduous tree from the birch family (Betulaceae), closely tied to damp habitats. In North Macedonia the most common are black alder (Alnus glutinosa), which grows along rivers and in floodplain woods, and gray alder (Alnus incana), more common in hilly and mountainous areas.
It is recognized by its dark, cracked bark, rounded leaves with a slightly notched tip, and by the small woody cones that stay on the branches through the winter. In spring it carries long hanging catkins from which the pollen is released.
Season and distribution in North Macedonia
The alder season runs from February to April, peaking most often in March. In mild winters flowering begins as early as late January. As with the other early-spring species, the course of the season is dictated by the weather: a few warm days in a row open the catkins, and a cold spell temporarily stops flowering.
Distribution follows the waterways. Most alder is found in the floodplain woods and belts along the Vardar, Crna, Pčinja, and Treska, in the riparian woods and around Lake Ohrid and Lake Prespa. Residents of the riverside parts of Skopje, Tetovo, and Kumanovo are more exposed than residents of the city centers away from the river.
Modeled data for North Macedonian cities
For cities in North Macedonia pelud.net does not show measured values but a score derived from the European CAMS model (via the Open-Meteo service). The model describes the start and course of the season and regional differences well, but it does not capture the local stand of alder two hundred meters from your building. This service uses CAMS modeled data for its dynamic three-day forecast.
Symptoms
- sneezing and a runny nose at the end of winter
- a blocked nose
- itchy, watering eyes
- itching of the palate and throat
- in asthmatics, worsening symptoms, especially in cold, dry air
The key difference from a cold: the trouble lasts for weeks, there is no fever, and the symptoms are more pronounced outdoors in dry, windy weather than indoors.
Cross-reactivity with birch, hazel, and food
Alder, hazel, and birch belong to the same order Fagales, and their main allergens are related. Someone who reacts to one of them as a rule reacts to the others, so the seasons link up: alder and hazel in February and March, birch in April, hornbeam and oak in May.
Because of the relationship to birch's main allergen (Bet v 1), oral allergy syndrome with apple, hazelnut, peach, carrot, and celery also occurs in alder allergy. Cooked or baked foods as a rule cause no trouble.
Treatment
- Second-generation antihistamines relieve sneezing, itching, and discharge.
- A nasal corticosteroid spray should be started as early as late January if you have had trouble in February in previous years — preventive introduction works better than reacting to already developed symptoms.
- Eye drops for pronounced conjunctivitis.
- Immunotherapy for birches and related species also covers alder, because it is applied to the shared allergens of the order Fagales.
Practical tips for sensitive people
- Do not write off February trouble as a cold — if it recurs every year at the same time, talk to your doctor about allergy testing.
- Plan walks along the river and through the riverside woods during February and March for the days after rain.
- In dry, windy weather keep the windows closed, and ventilate in the evening.
- Sunglasses and a scarf reduce the contact of pollen with your eyes and face.
- If you work in riverside woods or do logging, wear a mask — felling trees in season releases large amounts of pollen.
Note
This is not medical advice. For an assessment of symptoms, treatment, or immunotherapy, consult your doctor or an allergist.