There are 2 pollen allergens associated with lilac pollen, they are all allergens associated with airways.
Syr v 1 is a glycoprotein and is often referred to as “Ole e 1-like” as it closely resembles the main allergen in olive pollen. It has high cross-reactivity with the main allergens of other plants in the Oleaceae family.
Syr v 2 is a polcalcin protein , these are calcium binding protein commonly associated with pollen germination. These proteins are highly cross reactive and also considered to be panallergens.
Lilacs are members of the Olive Tree family. Pollen season is between May and June. This varies from country to country. It is considered to have low allergenicity as they are insect pollinated rather than wind pollinated. It may be an issue if you have a lilac pollen allergy and have the flowers in the house.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Lilac.php
The allergy resources page for lilac pollen covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with lilac pollen.
There is also regularly updated links to useful websites specifically for lilac pollen allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.