Home | Allergens | Methods | Allergy | Guidelines | Q & A | Scientific Doc | Dictionary | SEARCH  
Epidermals and animal proteins
Food of Animal Origin
Food of Plant Origin
Grass pollens
House dust
Molds and other Microorganisms
Occupational Allergens
Other allergens - Regional
Tree pollens
Weed pollens
Common pigweed
Common ragweed
False ragweed
Firebush (Kochia)
Giant ragweed
Goosefoot, LambĀ“s quarters
Japanese Hop
Marguerite, Ox-eye daisy
Plantain (English), Ribwort
Rough marshelder
rPar j 2 (recombinant)
Saltwort (prickly), Russian thistle
Scale, Lenscale
Sheep sorrel
Wall pellitory (judaica)
Wall pellitory (officinalis)
Western ragweed
w19  Wall pellitory (officinalis)
Parietaria officinalis
Family: Urticaceae
Common names: Wall Pellitory, Pellitory-of-the-Wall, Parietaire, Spreading Pellitory
Source material: Pollen

See also Wall Pellitory w21 (Parietaria judaica).

A weed species producing pollen, which often induces hayfever, asthma and conjunctivitis in sensitised individuals.

Allergen Exposure

Geographical distribution
Wall Pellitory is a common weed around the Mediterranean and along the west coast of Europe as far north as central England. It is found in Spain, Greece, Italy, Israel, and has been introduced in other parts of Western Europe and in Australia and Argentina. Two closely related species are found in the US and one in Brazil.

The genus Parietaria has about 10 species, which are highly cross-reactive to each other. Parietaria pollen allergens (officinalis, judaica, lusitanica, creatica) are one of the most common causes of pollinosis in areas where the plants grow. A close correlation exists between the species P. judaica and P. officinalis. In some geographical areas one species may dominate, and IgE antibodies to only one of the species can be found in sensitised individuals.

Parietaria officinalis is a sprawling, many-branched, bushy perennial weed, with brittle, reddish stems. It grows from 30 to 100 cm. The leaves are 8 to 17 cm long and oval in shape, with hairs on the veins on the lower surface. The leaves of P. judaica (w21) are about 5 cm shorter than those of P. officinalis (w19).

The inconspicuous green stalkless flowers are clustered in the leaf axils. They are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant). In many countries the Wall Pellitory flowers all year round but with distinct peaks in spring and around November. In some areas, Wall Pellitory may flower only from early summer to late fall. This plant is pollinated by wind.

The plant lives preferably on walls (hence the name), rocks, banks, and hedgebanks. Wall Pellitory may be used for medicinal purposes.

Par o I is a major allergen of Parietaria officinalis(1).

Par o 1 (13.5 kDa) and Par j 1 (12 kDa), the major allergens from Parietaria, are highly crossreactive(2). In this event, it may be that Par o 1 is a Lipid Transfer Protein, in lieu of Par j 1 being one.

A profilin has also been detected in Parietaria judaica pollen, but the allergen has not been fully characterised(3). As a high degree of cross-reactivity exists between this plant and P. officinalis, it is likely that the latter also contains a profilin.

See also the more extensively studied and highly cross-reactive Wall Pellitory W21.

Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the genus could be expected, as well as to a certain degree among members of the family Urticaceae(4). However, for Parietaria crossreactivity with other family members of different genuses does not appear to be the case in general. RAST-inhibition demonstrated the absence of cross-reactivity between Parietaria and Urtica(5,6). Also, utilising an ELISA inhibition test, no cross-reactivity could be demonstrated between Ramie (Boehmeria nivea), a member of the Urticaceae family, a weed widely distributed throughout Japan and Southeast Asia, and Parietaria (P. officinalis and P. judaica)(7).

Extensive cross-reactivity occurs within the Parietaria genus. Par o 1 (13.5 kDa) and Par j 1 (12 kDa), the major allergens from Parietaria, are highly cross-reactive, and a high homology has been shown between P. judaica (Par j 1), P. officinalis (Par o 1), P. lusitanica and P. mauritanica (Par m 1)(8,9).  

Although a profilin has not been characterised in Parietaria plants, by inference they must contain profilin(3). Significant but low antigenic cross-reactivity has been demonstrated among Mercurialis annua, Olea europaea, Fraxinus elatior, Ricinus communis, Salsola kali, Parietaria judaica and Artemisia vulgaris by several in vitro techniques(10). 

Sera from subjects sensitised to White Cypress, Pine, Italian Cypress, Ryegrass or Birch pollen were shown to have IgE antibodies that reacted with pollen from these and from Cocksfoot, Couch Grass, Lamb's Quarter, Wall Pellitory, Olive, Plantain and Ragweed. The authors conclude that the presence of pollen-reactive IgE antibodies may not necessarily be a true reflection of sensitising pollen species(11).

The recombinant Juniperus oxycedrus pollen allergen rJun o 2 (Cupressaceae family) has a significant sequence similarity to the calcium-binding proteins called calmodulins, and immunoblotting inhibition tests demonstrated that J. oxycedrus, J. ashei, Cupressus arizonica, C. sempervirens, Parietaria judaica, Olea europaea, and Lolium perenne pollen extracts were able to inhibit IgE binding to blotted rJun o 2(12). The inference is that that if close cross-reactivity occurs between Juniperus oxycedrus, other members of the Cupressaceae, and Parietaria judaica, then the possibility exists that these pollens may affect individuals sensitised to Pareitaria judaica and thus also toPareitaria officinalis.

Sensitisation to pistachio is common in Parietaria allergy(13).

Clinical Experience

IgE mediated reactions
Parietaria pollen can induce asthma, allergic rhinitis and allergic conjunctivitis.

In vitro determination of Specific IgE to P. officialis is a tool in detection of Parietaria sensitisation(14).

For further information see the more extensively studied and highly cross-reactive Wall Pellitory w21 (Parietaria judaica).

Compiled by Dr Harris Steinman, harris@zingsolutions.com

  1. Oreste U, Coscia MR, Scotto d'Abusco A, Santonastaso V, Ruffilli A. Purification and characterization of Par o I, major allergen of Parietaria officinalis pollen. Int Arch Allergy Appl Immunol  1991;96(1):19-27 
  2. Scotto d'Abusco AS, De Santo C, Menna T, Coscia MR, Oreste U, Geller-Bernstein C, Ruffilli A. Characterization of a dominant antigenic determinant of Par o I encoded by recombinant DNA. Clin Exp Allergy  1996 Feb;26(2):223-31 
  3. Benitez D, Garcia-Ortega P, Picado C, Mila J, Vives J, Martinez J, Vilella R. Specific immune response to Phleum pratense plant profilin in atopic patients and control subjects. Allergol Immunopathol (Madr) 2001;29(1):9-15 
  4. Yman L. Botanical relations and immunological cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09 
  5. Bousquet J, Hewitt B, Guerin B, Dhivert H, Michel FB. Allergy in the Mediterranean area. II: Cross-allergenicity among Urticaceae pollens (Parietaria and Urtica). Clin Allergy 1986;16(1):57-64 
  6. Corbi AL, Cortes C, Bousquet J, Basomba A, Cistero A, Garcia-Selles J, d'Amato G, Carreira J. Allergenic cross-reactivity among pollens of Urticaceae. Int Arch Allergy Appl Immunol 1985;77(4):377-83 
  7. Miura N. Ramie (Boehmeria nivea) pollen-induced bronchial asthma and allergenic cross-reactivity of ramie and Parietaria. Arerugi 1993;42(5):649-55 
  8. Scotto d'Abusco AS, De Santo C, Menna T, Coscia MR, Oreste U, Geller-Bernstein C, Ruffilli A. Characterization of a dominant antigenic determinant of Par o I encoded by recombinant DNA. Clin Exp Allergy 1996;26(2):223-31 
  9. Ayuso R, Carreira J, Polo F. Quantitation of the major allergen of several Parietaria pollens by an anti-Par 1 monoclonal antibody- based ELISA. Analysis of crossreactivity among purified Par j 1, Par o 1 and Par m 1 allergens. Clin Exp Allergy 1995;25:993-9. 
  10. Vallverdu A, Garcia-Ortega P, Martinez J, Martinez A, Esteban MI, de Molina M, Fernandez-Tavora L, Fernandez J, Bartolome B, Palacios R. Mercurialis annua: characterization of main allergens and cross-reactivity with other species. Int Arch Allergy Immunol 1997;112(4):356-64
  11. Pham NH, Baldo BA. Allergenic relationship between taxonomically diverse pollens. Clin Exp Allergy 1995;25(7):599-606 
  12. Tinghino R, Barletta B, Palumbo S, Afferni C, Iacovacci P, Mari A, Di Felice G, Pini C. Molecular characterization of a cross-reactive Juniperus oxycedrus pollen allergen, Jun o 2: a novel calcium-binding allergen. J Allergy Clin Immunol 1998;101(6 Pt 1):772-7 
  13. Liccardi G, Russo M, Mistrello G, Falagiani P, D'Amato M, D'Amato G. Sensitization to pistachio is common in Parietaria allergy. Allergy 1999;54(6):643-5 
  14. Scordamaglia A, Passalacqua G, Ruffoni S, Parodi MN, Ciprandi G, Canonica GW. Two screening methods for detection of specific IgE to inhalant allergens. Comparison with skin prick test and RAST. J Investig Allergol Clin Immunol  1991 Oct;1(5):324-9
Last update: 2002
© Copyright Phadia AB, 2002 - ver 3.1
Photographs © Copyright Dr H Steinman/Phadia AB