Hay fever on a Mediterranean holiday in almost any month from spring to autumn? Wall pellitory (Parietaria) is a small weed that grows out of old walls and releases pollen for most of the year, and in Italy and other coastal regions it is one of the leading causes of hay fever. Our test checks IgE to Parietaria and its main allergen Par j 2, as part of 300 allergens and allergen components.
Wall pellitory (Parietaria judaica) and its close relative Parietaria officinalis are low, reddish-stemmed weeds from the nettle family. They have no sting, and you will mostly see them growing out of walls, steps and ruins.
The plant is wind-pollinated and flowers for months at a time. Around the Mediterranean that makes it one of the longest pollen seasons of any plant, and it is a leading cause of hay fever and pollen asthma in southern Italy and other coastal regions.
In Finland, Ireland, the Netherlands and Germany it grows only patchily, so it rarely matters at home. It matters for travellers, for people who spend long stretches in the south, and for anyone who grew up there.
People sensitised to Parietaria report hay fever symptoms: sneezing, a runny or blocked nose, itchy eyes and, more often than with many pollens, a cough or wheezing.
Because the season is so long, symptoms can feel almost year-round in the south rather than tied to one month. That is easy to confuse with house dust mites, which a separate result can help untangle.
Parietaria's main allergens, Par j 1 and Par j 2, are lipid transfer proteins (LTPs). Many plant foods also contain LTPs, such as peach's Pru p 3, but the Parietaria LTPs are structurally different and generally do not cross-react with them.
That makes Par j 2 a reliable marker for genuine Parietaria sensitisation. A positive Par j 2 does not on its own point to a food problem, and a positive peach LTP does not explain a Parietaria result.
From a finger-prick sample, the lab measures IgE to the two Parietaria markers below as part of 300 allergens and allergen components. The other main Mediterranean pollens, such as olive, cypress, plane tree, Bermuda grass and Russian thistle, are on the same report, and so are the house dust mites.
A positive result means your blood shows IgE to Parietaria pollen. That is sensitisation, not a diagnosis. Each value gets a class from Negative to Very high, to discuss with a doctor.
Page last updated
One finger-prick sample checks IgE to 300 allergens and allergen components, from birch and peanut to cat and house dust mite. Post it to the lab, and about 5 days after it arrives you get a value for every one. Our plain-English guide shows you how to read them. €399 in total, €1.33 per allergen.
Around the Mediterranean, Parietaria flowers from about March to October, with a main peak in spring and a second one in late summer. In mild coastal areas there can be pollen in the air for most of the year.
They are in the same plant family, but wall pellitory has no sting and its pollen is far more allergenic. Stinging nettle pollen rarely causes hay fever.
Yes, on old walls in some places, but in small amounts. It is rarely a major pollen in northern Europe. It matters most if you travel to, live in or grew up in southern Europe.
Usually not. Both contain lipid transfer proteins, but Parietaria's are different enough that they generally do not cross-react with food LTPs. The panel measures both, so you can see them side by side.
