Parietaria Allergy – Symptoms, Cause, Treatment, and More

Parietaria Allergy

The Parietaria is a herb belonging to the Urticaceae family. It is an important cause of allergy in the countries of the Mediterranean area. Those who suffer from Parietaria allergy are ill for almost the whole year: the pollen season can in fact last from February to October.

It is also known by the name wall grass, vitriol grass, crown grass, and wind grass. It is widespread in all Italian regions, in particular the central-southern regions, up to an altitude of 1000 meters.

In particular, in the southern regions, the pollen period is very prolonged. It begins in February-March, reaches its peak between April and May, and lasts until July. A second peak may follow between September and October. In the northern regions, the pollen peak occurs between May and June and a lower pollen presence lasts throughout the summer.

Symptoms of Parietaria allergy

The Parietaria allergy symptoms are not different from other pollen allergies. Most people experience the allergy symptoms after direct contact with Parietaria pollen. The common symptoms of Parietaria allergic reactions are:

  • Sneezing
  • Stuffy and runny nose
  • Itchy on the skin, nose, and ears
  • Itching in the throat or palate
  • Itchy watery eyes or allergic conjunctivitis
  • Eczema or Hives
  • Difficulty Breathing or Asthma
  • Anaphylactic Shocks (In severe cases)


Parietaria pollen is the most common cause of allergic reactions in most people. Here are its species that cause an allergic reaction:

  • ParietarJudaicaica
  • Parietaria officinalis
  • Parietaria floridana
  • Parietaria praetermissa
  • Parietaria debilis
  • Parietaria pensylvanica
  • Parietaria cretica

How many people suffer from Parietaria allergy?

The frequency of awareness is very high. Some statistics report an incidence of 10-60% on the Spanish Mediterranean coast and about 25% in the French Mediterranean area. While in Italy the frequencies are around 30% in the central regions, up to 70% in Liguria.

Being present for many months, patients allergic to the Parietaria suffer from allergic rhinitis (and not only!) Almost all year round. From a clinical point of view, the allergy to the Parietaria is a higher prevalence of cases of bronchial asthma than other pollinosis.

It is linked both to the small size of the Parietaria pollen which so can reach the bronchial mucous membranes more easily. In part due to the presence of impurities on the pollen surface that can directly irritate the airways.

If neglected and not properly addressed, allergy to Parietaria can degenerate into asthma. It is important not to neglect even the mildest symptoms, especially in children. The period of life in which there is a greater possibility of intervening on the allergic march.

Treatment of Parietaria Allergy

The allergy to Parietaria is no different from the other allergies from inhalants. It is therefore treated with the three pillars that we have discussed below.

Reduction of allergen exposure

For example, avoid going out on windy days or just after a storm, when the pollen concentration is higher. Or, again, avoid organizing trips out of town where we know there is a strong presence of Parietaria.

Specific immunotherapy (allergy shots)

Specific immunotherapy has been shown to be effective and tolerated in several clinical trials. There are different methods of administration (sublingual or subcutaneous). It is the only tool capable of acting at the root of the problem, fighting the disease, and not just the symptoms.

Symptomatic medications

In parallel with the allergy vaccine, when this is not enough to control symptoms. Contact your Allergist, he will diagnose your allergy and will prescribe you medicines.