The annual airborne spore offensive is once again causing runny noses, swollen eyes and uncontrollable sneezing in thousands of people suffering from hay fever, or pollinosis. Between 20 to 30 per cent of Finns suffer from pollen allergies. Amongst the most common culprits are birch, alder, hazel, grass and mugwort.

As soon as temperatures settle firmly above zero, plants spring to life and begin to emit microscopic spores that can be carried several hundred of kilometres away by the wind. Alder and hazel lead the pollen season in March and April. Currently alder pollen counts are moderate or abundant in southern and western parts of Finland.

“This year we’re a little behind schedule compared to an average year in terms of alder. It usually reaches a peak blooming period by the end of March, but this year it started in April,” says researcher Anna-Mari Pessi from the University of Turku Aerobiology Unit, which monitors airborne pollen.

According to Pessi there are great differences in the intensity and duration of the pollen season from one year to the next. The blooming of birch trees in particular has a certain rhythm that can be forecast with some precision. A strong bloom one year often means a weaker one will follow, although weather and cross-border air flows may affect the actual pollen counts.

Preventive Relief

Updated information about pollen counts allows allergy sufferers to anticipate peak pollination periods and to take preventive medication.

“We usually recommend that sufferers begin treatment a week or two before blooming season,” says Anne Vuorenmaa of the Allergy and Asthma Federation. Some prefer localised treatments such as eyedrops, nasal sprays etc, while others take general antihistamines. An increasing number are also turning to allergen immunotherapy.

“Immunotherapy has proved very effective,” Vuo-“¨renmaa says. “The treatment takes three years and gives up to seven years’ or even 12 years’ protection. According to some studies it may even prevent asthma from breaking out.”

The new national allergy programme, launched in 2008, is set to promote immunotherapy. Whereas treatment for hay allergies, is now available in pill form, other types of pollen allergies can only be treated with injections. Research is underway to develop a pill for immunotherapy against birch, the most common cause of pollinosis in Finland.

This year there is some good news for birch allergics, though.

“The bloom of birch this summer is likely to be less intense than usual,” Pessi says. “Alder on the other hand always blooms with full force, and as for grass and hay, there are so many different species that we can’t possibly predict what kind of bloom we’ll have.”

Matti Koskinen – HT
Lehtikuva – Marja Airio