Spring is a time when many patients begin to experience a marked worsening of their inhalant allergy symptoms. At this time of year, tree pollen is of particular significance, particularly that from willow, ash and birch. These are among the most common causes of seasonal allergic rhinitis, itchy eyes, sneezing and an exacerbation of respiratory symptoms. For those with allergies, this means they need to be more cautious, especially on dry, sunny and windy days.