A weed species producing pollen, which may induce hayfever, asthma and conjunctivitis in sensitised individuals.

Allergen Exposure

Geographical distribution
Lenscale is native to the temperate and tropical regions of North America, but a few species are grown as ornamentals throughout the world because of their attractive greyish foliage. The different Atriplex species are closely related to each other, and consist of annual and perennial weeds and shrubs.

 

Lenscale is a fast-growing, compact, woody perennial shrub usually growing between 0.15 and 1.52 m in height, but sometimes reaching 3m. The plant is deciduous in arid areas, but tends to be evergreen elsewhere. Numerous slender and wide-spreading branches contain grey-green, thickish leaves 1.0 to 5.0 cm long and 0.5 to 4.0 cm wide, with a fine, scaly surface.

 

Lenscale produces inconspicuous yellow flowers from May to August. It is not yet clear whether the flowers are primarily dioecious (plants are male or female) or monoecious (individual flowers are either male or female, but both sexes can be found on the same plant). The plant is wind-pollinated and greatly contributes to the pollen loads of arid regions. These plants have the ability to alter their sexual state from one season to the next in response to environmental conditions. Many seeds are borne on bracts and wind-dispersed. The fruits and seeds mature from September to October.

 

Environment
Lenscale often occurs along seashores and in other saline soils, especially in arid regions, and has been used for windbreaks, borders, and range management.

 

All parts of the plant are edible. Native Americans ground this plant's seeds into meal for piñole or porridge, and for an emetic.

 

Allergens
No allergens from this plant have yet been characterised.

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 Chenopodiaceae (1).

 

Atriplex latifolia, Beta vulgaris, Salsola kali and Amaranthus retroflexus were compared with an extract from Chenopodium album by both in vivo and in vitro methods. The presence of common allergenic determinants was suggested. This implied that as A. latifolia is cross-reactive with A. lentiformis, cross-reactivity will occur between this plant and other members of the Amaranthaceae (2).

Clinical Experience

IgE mediated reactions
Lenscale pollen may induce asthma, allergic rhinitis and allergic conjunctivitis.

Compiled by Dr Harris Steinman, harris@zingsolutions.com