(Goosefoot or Saltbush family)
This is a large family of about 1400 species of low-growing plants in 102 genera. Nearly all are found in, and are tolerant of salted earth in sea shores, deserts, etc. Some are xerophytic and resemble cacti.
Many are of major economic importance as food plants. These include Atriplex L. spp., Beta vulgaris L. (beetroot, sugar beet, mangold wurzel, Swiss chard), Chenopodium L. spp., and Spinacia oleracea L. (spinach). The burning bush (Kochia scoparia Schrader f. trichophylla Schinz & Thell.) is commonly grown in gardens as an ornamental bedding plant.
Chenopodium ambrosioides L. var anthelminticum A. Gray is cultivated for its anthelmintic volatile oil known as American wormseed oil, chenopodium oil, or Baltimore oil. A Sumerian recipe for soap (circa 2500 B.C.) utilised Salicornia fruticosa L. as the source of alkali (Rowley 1960).
A variety of dermatoses, including allergic contact dermatitis, photodermatitis, and mechanical injury have been reported. Nothing is known about the nature of the allergens nor the phototoxic principles.
A pellagra-like syndrome has occurred in starving persons who ate garden orache (Tyszlukiewicz & Zelazowski 1964).
Women who ate the plant under famine conditions in China (where the plant is known as Noong Jang-ai) developed oedema and then a pruritic bullous eruption of exposed skin. Men where rarely affected (Martin, cited by Maxwell 1929). This disorder, known as atriplicism, has been interpreted as a photosensitisation (Cairns et al. 1968) and attributed to ingestion of Atriplex serrata and Amaranthus mangostanus L. (fam. Amaranthaceae). King (1966) records that species of both of these genera tend to grow on garbage dumps around human habitation.
A. littoralis was reported by Matignon (1897, 1900) to produce adverse effects.
The sharply pointed fruits of this Australian species can produce mechanical injury (Cleland 1925).
Dermatitis in the sugar beet industry affected two thirds of workers employed in the crystallising department. Sugar appeared to be responsible for the dermatitis and secondary infection was common (Prosser White 1934).
A food handler who had contact dermatitis showed positive patch test reactions to beet and to spinach (Spinacia L.). Control tests were not recorded (Morris 1954). A positive patch test reaction to beet pulp was observed in a dock worker who had allergic contact dermatitis from cattle fodder products including maize and barley (fam. Gramineae) and brans (Malten 1970).
Beet pollen may cause pollinosis (Wodehouse 1971).
Nater & Grosfeld (1979) reported contact dermatitis from the herbicide Betanal(TM) (containing phenmedipham) which is used on sugar beet.
Between 100 and 150 species are found in temperate regions (Willis 1973), a number of which have been used for food by man (Usher 1974).
A pellagra-like syndrome has occurred in starving persons who ate unspecified species of Chenopodium (Grzybowski 1948, Sebastynski 1960, Yu 1957, Lukács 1958). Poisoning in animals from ingestion of the plants and human poisoning from ingestion of chenopodium oil (see Chenopodium ambrosioides var anthelminticum) does not appear to produce photosensitivity (Kingsbury 1964).
Contact with the plants has been reported to cause dermatitis (Becker & O'Brien 1959) and to evoke photodermatitis (Lubieniecki 1961).
The pollen of some species, especially Chenopodium album, can cause pollinosis (Wodehouse 1971).
The plant is cultivated in India for fodder and as a pot-herb, and is a ubiquitous weed. Cases of photosensitisation have been seen following its ingestion as a green vegetable (Behl & Captain 1979). It is said to be useful in the treatment of vitiligo (Behl 1973).
This species produced a positive patch test reaction in one of 50 patients investigated for "weed dermatitis" (Shelmire 1939).
Aplin (1976) notes that the volatile oil has been reported to cause an irritating itch in a person who handled the plant.
Chenopodium oil, otherwise known as American wormseed oil or Baltimore oil, is extracted from the flowers and fruits of the plant by steam distillation. It consists chiefly of ascaridole and para-cymene. As well as being used as an anthelmintic (for which purpose it is effective but possesses toxic side effects), it has value as a fragrance raw material.
Undiluted chenopodium oil was found to be irritating when applied to the skin of mice, swine, and rabbits, but was non-irritant when diluted to 4% in petrolatum and applied for 48 hours in a closed patch test on human skin. No phototoxic effects on the skin of mice and swine could be demonstrated with the undiluted oil; attempts to induce contact sensitivity to 4% chenopodium oil in petrolatum in 25 human volunteers were unsuccessful (Opdyke 1976, Forbes et al. 1977).
This species produced negative patch test reactions in all of 50 patients investigated for "weed dermatitis" (Shelmire 1939).
This species, which grows in the Sahara desert, forms compact, round bushes bearing small yellow thorns (Swift 1975).
An extract of this species produced negative patch test reactions in all of 50 patients being investigated for "weed dermatitis" (Shelmire 1939).
The common name pigweed is also used for certain members of the family Amaranthaceae.
The plant is used for headlice and as a hair tonic to promote growth (Train et al. 1957).
The pollen of this species can cause pollinosis (Wodehouse 1971).
The leaf tip is armed with a sharp spine which may prove physically damaging to the field worker, who may even fail to find gloves thick enough to keep the spines out of his fingers. The spines may break off under the skin (Watt & Breyer-Brandwijk 1962).
Since about 1900, this plant has become an agricultural weed in North America. The spines of the plant cause irritation to men and horses (Pammel 1911, Schwartz et al. 1957). In New Mexico, USA, a disorder known a tumbleweed dermatitis can occur following skin contact with this plant; direct mechanical injury from the spines appears to be the cause. An extract of the plant produced negative patch test reactions in all of 50 patients being investigated for "weed dermatitis" (Shelmire 1939). Powell & Smith (1978) carried out patch, scratch, and photopatch tests with Russian thistle and an extract. These tests showed that in non-sensitive persons, dermatitis was caused only by mechanical irritation from plant floral bracts. In sensitive individuals, the bracts pierced the skin and stimulated an urticarial reaction.
Migaki et al. (1969) noted that in areas of southwestern USA, spines from Salsola pestifer are sometimes found embedded in the tongues of range cattle. Spines in tongues can predispose to bacterial infection.
The numerous branches of this spreading deciduous shrub bear rigid spines capable of inflicting mechanical injury. It should not be confused with Larrea tridentata Cov. (fam. Zygophyllaceae), an unrelated plant also known as greasewood.
Schwartz et al. (1957) record that in the canning industry, workers employed in packing spinach are subject to a dermatitis resembling that produced by Toxicodendron Mill. (fam. Anacardiaceae). Spinach can cause dermatitis in housewives (Shelmire 1940).
Dermatitis caused by handling spinach was recorded by Brown (1922). A food handler was contact sensitive to spinach and to beet (Beta L.). A packer of spinach had oedema due to cold (Morris 1954). A vegetable dealer had dermatitis from contact with spinach, and asthma from ingestion of spinach and also green peas (Pisum L., fam. Leguminosae). Patch tests with spinach reported by Zohn (1937) and by Singh et al. (1978) produced negative results. However, Sinha et al. (1977) observed a positive patch test reaction in 1 of 53 patients who had hand dermatitis suspected to be caused by vegetables.
Ingestion of Threlkeldia proceriflora F. Muell., an Australian species, is reported to cause photosensitisation in animals (Hurst 1942). Kochia scoparia Schrader, the summer cypress, was responsible for photosensitisation in cattle, sheep, and horses during drought years in the Argentine in 1942 and 1943 (Kingsbury 1964).