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MALVACEAE(Mallow family)
1000 species in 75 genera are found in tropical and temperate regions. Included in this family is the well-known baobab (Adansonia digitata L.) whose trunk may reach 9 metres in thickness (Menninger 1967). Kapok, an oily cotton-like fibre, is derived commercially from the silky hairs on the ovaries of Ceiba pentandra Gaertn. and, to a lesser extent, from Bombax ceiba Burm.f. and possibly other species of Bombax L. and Ceiba Mill. (Irvine 1961, Menninger 1967, Usher 1974, Mabberley 2008). Balsa, the timber from Ochroma pyramidalis Urb., is extremely light in weight and is much used in model aeroplane building and similar activities. It is also used locally in South America for making canoes. Certain trees formerly classified in the Bombacaceae may be responsible for mechanical injuries. Other irritant properties have been rarely encountered.
The immature mucilaginous fruit is the vegetable named okra, a common vegetable in warm climates, much used in soups and stews (Howes 1974). The hairs on the plant are a common source of inflammation and itching (Morton 1975). Weber (1937) included this species among plants known to cause dermatitis. Behl et al. (1966) observed allergic contact dermatitis in gardeners and housewives from this species. In a housewife working in a kitchen garden, dermatitis affected the left index finger and thumb. A positive patch test reaction was obtained. Patch tests carried out using the leaves of this species crushed in a small quantity of normal saline elicited a positive reaction in 1 of 5 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978).
This species provides ambrette seed of perfumery (Arctander 1960). The powdered seed may be used as an insecticide. When mixed into a paste with milk, it may be employed as a topical remedy for itch (Wren 1975). Over 100 species are found in tropical and subtropical regions. Abutilon avicennae provides a useful fibre named Chinese jute. The leaves of some species can produce irritant patch test reactions. Reactions registered as allergic should be accepted with caution (Hjorth 1968, Agrup 1969). In two cases of contact dermatitis attributed to Indian mallow, strong positive patch test reactions were observed (Underwood and Gaul 1948). The seeds have a taste like ginger (Zingiber officinale Roscoe, fam. Zingiberaceae), and the leaves and powdered bark are used as a condiment. The blossoms are extremely malodorous and are pollinated by bats (Menninger 1967, Howes 1974). The tree burns with an irritating smoke. It can be dangerous to walk over the place where the rotten tap-root of a baobab is, because one can drop down into a large cavity filled with decaying pulp (Irvine 1961). Stuart (1911), referring to Althaea rosea, noted that in Chinese traditional medicine, the root stalk of this plant (which is known as shu kuei) when bruised is applied to all sorts of ulcers. The hairy leaves, stems and pollen are irritant (McCord 1962). Hjorth (1968) observed irritant patch test reactions from the plant and noted that reactions registered as allergic should be accepted with caution. In two cases of contact dermatitis attributed to hollyhock, strong positive patch test reactions were observed. The powdered or crushed roots make a good poultice, which may be relied upon to remove the most obstinate inflammation and prevent mortification … hence its alternative name "mortification root" (Wren 1975). Stuart (1979) refers to the external use of marshmallow as a poultice for leg ulcers. The timber known as trincomali is derived from this tree. It is said to have irritating qualities (Zschokke cited by Arnold 1968).
The buttressed trunk is usually very spiny on young trees (Conn & Damas 2005j, Tang et al. 2007).
Alone, the timber derived from these species, was listed by Oleffe et al. (1975a) as a cause of dermatitis in the Belgian timber industry. Twigs of this species have been found to be inhabited by stinging ants (Wheeler 1942). Handling of the seeds caused irritation of the fingers and eyes (Hurst 1942).
This shrub is armed with short, hooked prickles (Standley 1937b). Cuts and scratches from the thorns on the canes become inflamed and heal slowly (Allen 1943). The long spines on the fruits are a hazard for persons who drink the water from the stems (Irvine 1961).
Some varieties / cultivars have spiny trunks, others smooth (Irvine 1961, Menninger 1967). The tree is not recommended for town planting since the floss of the seed capsules (from which kapok is produced) is irritating to the eyes and nose (Irvine 1961). Colonies of stinging ants have been found inhabiting twigs of this tree (Wheeler 1942).
These species furnish the chief supply of the fibre jute or gunny. The stems are cut and retted in water and the fibre is beaten out. Oils are used for softening the fibre. Burlap is a coarsely-woven textile made from jute fibre. Mineral oil used in the processing can produce folliculitis and oil-acne. In contrast to jute, flax (Linum) requires no added oil in its manufacture and oil-acne is less commonly observed in flax workers. Fish oil used for softening jute fibre can liberate irritating fatty acids as it decomposes. Potassium hydroxide, used as an additive, can produce irritation (White 1887, Curjel and Acton 1924, Stevens and Jordani 1938, Schwartz et al. 1957, Simons 1952). Eczema with ulceration of the skin of the legs from standing in water, and respiratory symptoms can occur in jute-workers (Bhar 1952). Burlap can also produce respiratory symptoms (Stevens and Jordani 1938). Kinner et al. (1955) found no evidence of sensitisation to jute; skin cancer can result from exposure to oil used to treat the jute. von Reis & Lipp (1982) noted the following on an herbarium sheet: "Caution! Powder dangerous to eyes." The large malodorous fruits, which are covered by a hard shell bearing many sharp conical spines (Smitinand & Scheible 1966), are a hazard to passers-by as they fall from the tree. Indeed, Menninger (1967) describes the durian as the world's most dangerous fruit. Eating the durian fruit, which is considered to be a delicacy in South East Asia, can cause irritation especially in the angles of the mouth (Fasal 1945).
The leaves bear irritant brown hairs that easily rub off and can become airborne (Wilkinson et al. 1994, Mabberley 1997). According to Remington et al. (1918), the bark of Fremontia californica is said to have the same properties as slippery elm bark (see Ulmus rubra Muhl., fam. Ulmaceae), and to be used for a similar purpose. Some 20 species are found in tropical and subtropical regions. Cultivated forms are grown in Old and New Worlds to provide cotton which consists of long hairs covering the seeds. Cotton seed oil is obtained by crushing the seeds; the oil cake, following expression, is used for cattle feed. Commercial cotton may be derived from four main species (Howes 1974). The hairs of cotton plants are irritant (Behl et al. 1966). Pseudophytodermatitis, can result from contact with cotton and its derivatives. Cotton, like cereals and straw (Gramineae), can be infested with a mite, Pyemotes (pediculoides) (Van Thiel 1953). Nixon (1915a) provided an incident report of an eruption following the handling of bulk cotton seed cargoes from Alexandria. Two-thirds of the 50 men handling the cargoes were affected. The eruption was ascribed to a mite living in the cotton seed dust. Agricultural chemicals (Karimov 1970), a varnish used in cotton mills (Schwartz and Pool 1933), and chromates present in cotton used in upholstery (Nixon 1915b) have been implicated. Type I hypersensitivity reactions to cotton seed oil (Brown 1929, Spies et al. 1942, Bernton et al. 1949, Figley 1949, Harris and Shure 1950, Plymyer 1959) are probably attributable to a water soluble proteinaceous fraction of the oil. Cotton seed was implicated in a death from allergy testing by intradermal injection of 0.02ml of an extract (Harris & Shure 1959). Atopic patients scratch-test sensitive to cotton seed protein were found to be unaffected by ingestion of cottonseed oil (Bernton et al. 1949). In discussion of this paper, reference was made to mouth ulceration and oedema of the lips from ingestion of the oil in a sensitive individual. However, patch tests with the oil in sensitive atopic patients were negative. Taub (1945) listed sources of contact with cotton seed oil which was formerly much used in topical therapy and in cosmetics. Cross-sensitivity was observed to kapok (Ceiba, fam. Bombacaceae) (Brown 1929). Respiratory diseases (byssinosis) can occur in cotton textile workers (Merchant et al. 1972). Cancer of the scrotum in cotton spinners was reviewed by Brockbrank (1941). [Information available but not yet included in database] The sawdust irritates the throat and nose (Timber Development Association 1963/64, personal communication to Woods and Calnan 1976). The wood is said to be irritant (Orsler 1973). The wood can produce dermatitis in construction workers (Raymond 1959). 300 species are found in tropical and subtropical regions. Hibiscus rosa-sinensis is used to blacken the eyebrows and shoes and the young leaves are eaten as spinach (Irvine 1961). Hibiscus sabdariffa is used for making jelly (Behl et al. 1966). Hjorth (1965) observed allergic contact dermatitis from species of the genus with significant positive patch test reactions. A case of periocular eczema was traced to Hibiscus (Kaalund-Jørgensen 1951).
[Information available but not yet included in database] The wood smells peppery when worked and causes sneezing (Stone 1924, Record and Mell 1924). Referring to Hibiscus irritans, Watt & Breyer-Brandwijk (1962) noted that practically all parts of the plant are covered with sharp stellate hairs which can penetrate and become embedded in the skin. The stem is thickly covered with short white hairs amongst which are irritating bristles (Watt & Breyer-Brandwijk 1962).
[Information available but not yet included in database] The name of this plant was originally published as Lagunaria patersonii, which remains in common use. Its large seed pods contain irritant hairs. Six species are found in warm regions of America and in the West Indies. The plants have rough hairs.
This species was listed as a cause of mechanical injury by Oakes & Butcher (1962). This species was reported to produce dermatitis (Pardo-Castello 1923). Wren (1975) notes that this species may be used as a substitute for marshmallow (Althaea officinalis L.); and that a cataplasm of the leaves applied to bee or wasp stings "eases the smart". Stuart (1979) also refers to its use as a soothing poultice. The wood was introduced from Nigeria into the world market in the thirties and its irritant properties were soon recognized (Bridge 1935). The fine dust from working the wood produced sneezing, sore throat, nosebleeds, headache and dermatitis (Horner and Wigley 1936, Bourne 1956, Salamone et al. 1969). Handbook of Hardwoods (1956), Hublet et al. (1972), Orsler (1969), Oleffe et al. (1975), Reinl (1965) and Zafiropoulo et al. (1968) refer to dermatitis from the wood. Salamone et al. (1969) found skin irritation with a follicular eruption in a minority of their patients; patch tests to the wood produced negative reactions. Mucosal irritation affected many more. Hand-sanding of the wood was responsible for dermatitis in seven workers; the fine dust was responsible; cabinet-makers, sawyers and planers were not affected (Bourne 1956). In 27 workers in the furniture industry who developed dermatitis, patch tests to aqueous extracts of the wood produced positive reactions in 70% of cases alcoholic extracts in only 26% (Hanslian and Kadlec 1965). Species of this genus are among the six commoner causes of contact dermatitis from woods in France (Zafiropoulo et al. 1968). Borrie (1956) investigated 283 cases of dermatitis of the eyelids and found contact dermatitis to represent the third largest group (47 cases). Of these two cases were caused by mansonia wood, one by teak wood (Tectona grandis L.f., fam. Labiatae), two by chrysanthemum (Dendranthema, fam. Compositae) and one by turpentine (Pinaceae). Woods and Calnan (1976) reported four patients contact sensitive to mansonia wood. One was a female cleaner who only swept up sawdust and had dermatitis of the feet While the three men were a joiner, a cabinet-maker and a sawmill grinder. Positive patch test reactions were observed to mansonia wood dust. Teak (Tectona grandis L.f., fam. Labiatae) produced a positive patch test reaction in one of the cases, weakly positive (+) in another. Cross-sensitivity to Dalbergia was observed in one case an to Entandrophragma in another. Chemistry Mascré and Paris (1939) found in the bark a cardiac glycoside which they called mansonine. Several other glycosides related to strophanthin have since been found in the bark and heartwood (Frèrejacque 1951, Sandermann and Dietrichs 1959). Sandermann and Dietrichs isolated a quinone, mansonia-quinone from the heartwood and showed by patch tests that it was the skin-sensitiser in their case. Schulz (1962) obtained positive patch tests with mansonia-quinone in three more patients who gave negative results with the glycosides and other constituents. At least nine quinones have now been isolated, and shown to have a sesquiterpenoid structure (Marini-Bettolo et al. 1965, Galeffi et al. 1969). The wood can produce dermatitis (Bois Tropicaux 1966). Bristles present on the inner side of the woody fruit capsules can produce mechanical injury to the skin (Burkill 1935, Corner 1952). Woods and Calnan (1976) received a personal communication that some complaints of irritation by wood were received by the Forestry Department of Ibadan, Nigeria.
The wood, known as balsa or corkwood, is said to be irritant (Hanslian & Kadlec 1966).
Referring to Bombacopsis fendleri, Standley (1937b) noted that the trunk of this tree is densely armed with hard, sharp prickles. This tree provides a valuable timber. Hausen (1970) cites Lewin (1928) for an injurious effect from the wood. According to Woods and Calnan (1976) Pterospermum indicum is an incorrect name given by Lewin (1928) to amboina wood, which is in fact Pterocarpus indicus. He mentions another Pterospermum sp. used as a fish poison, but it produces no commercial timber. The wood is listed as injurious by Sandermann & Barghoorn (1956). A sawyer who had dermatitis showed a weak positive patch test reaction to the sawdust of this species and reactions to Spondias and Terminalia (Woods and Calnan 1976). Control tests were not recorded. 200 species are found in warm regions, especially in America. Some have spines. Sida rhombifolia provides a fibre.
This species was listed as an irritant by Pammel (1911). The hairs of the leaf have an irritant effect on the skin. Patch tests to the leaf produced positive reactions in 90% of 511 patients but extracts of the leaf produced negative reactions (Schulze 1940). He concluded that contact sensitivity was not involved but Kuske and Bandi (1958) observed that a small number of persons tested showed eczematous reactions to the leaves. 300 species are found in tropical regions. The seed pods of several species possess small hairs which cause intense itching on penetration of the skin (Allen 1943, Watt & Breyer-Brandwijk 1962).
The inside of the seed pods is covered with stiff bristles that penetrate the skin easily and cause intense irritation (Standley 1937b, Dahlgren & Standley 1944). This tree provides a useful timber.
This tree is a locally important source of timber. The wood dust is irritant (Anon 1957, MacKenna and Horner 1954, Zafiropoulo et al. 1968). Woods and Calnan (1976) could find no case reports to support the inclusion by MacKenna and Horner (1954) of the wood among those woods whose "chief, if not only effect, is on the skin". [Information available but not yet included in database] [Information available but not yet included in database] Irritant hairs are present on the stems and fruits (Arnold 1968). The dried exudate of the tree forms karaya gum (Indian tragacanth) which has in the past been used to adulterate Gum Tragacanth from Astragalus (Trease & Evans 1966, Smith & Montgomery 1959) but is now itself an article of commerce. Hog or Caramaria gum is an inferior grade mixed with fragments of bark. The resin of Anacardium occidentale is used as a substitute for karaya gum and Gum Arabic (Acacia) (Figley 1940). Karaya gum can cause atopic symptoms and urticaria (Figley 1940, Bowen 1939, Feinberg and Schoenkermah 1940, Greenberg and Lester 1954). According to Schwartz et al. (1957) karaya gum in hand cream can cause contact dermatitis. 30 species are found in tropical America. Several provide cacao, cocoa or chocolate. Cocoa butter is formed by pressing the seeds (beans). Theobromine is present in the beans (Budavari 1996). The bark yields a fibre. The plant possesses irritant hairs (Burkill 1935, Watt & Breyer-Brandwijk 1962) which affect gardeners and those who prepare indigenous drugs (Behl et al. 1966). Early reports of dermatitis in chocolate-makers were reviewed by Prosser White (1934). Gardiner (1922) reported six cases. Schwartz et al. (1957), Samitz (1950), Queries and Minor Notes (1921), Weber (1937), Key (1961) provide additional reports. Morris (1954) reported a positive patch test reaction to chocolate. Dermatitis in a chocolate factory and subsequent "hardening" were observed by Goldsmith and Hellier (1954). Greenberg and Lester (1954) reviewed reports of irritation by cocoa butter and considered it innocuous. Cocoa butter is considered to be a known allergen and is therefore removed from certain brandname cosmetics (Anon 1973). This plant was listed as vesicant for the skin by Quisumbing (1951). The leaves are used for counter-irritant purposes. The upper surfaces of the leaves are usually covered with honey-dew. Effects of aphids which produce honey-dew are note under Acer (fam. Aceraceae). The pollen of some species has been suspected of causing hayfever (Wodehouse 1971). American lime or bass wood was included in a list of irritant plants and woods by Schwartz et al. (1947, 1957). This species from West Africa forms a large tree from which a useful timber is derived. The timber is known as obeche or African whitewood. Other colloquial names include abachi, wawa, and samba. The wood was at one time sold in Liverpool as satinwood (Irvine 1961). Bridge (1937) reported a case of asthma due to the sawdust, skin tests being positive to this wood and negative to other woods. Oehling (1963) described 3 cases of asthma from the wood, one also sensitive to Terminalia. Contact urticaria could be produced by rubbing obeche wood on the skin. Orsler (1973) received trade reports of asthma and general symptoms from the wood dust. Woods and Calnan (1976) received a personal communication of dermatitis from a lavatory seat made of the wood, with a positive patch test reaction. Hausen (1970) found no alkaloids or quinones in the wood. Hublet et al. (1972) and Oleffe et al. (1975) reported unspecified muco-cutaneous effects from the wood in Belgium. The wood seems to be less noxious than mansonia (Zafiropoulo et al. 1968). Daniels et al. (2002) reported that a proprietary Wau Wa Cream made in Ghana, labelled as containing extract of wau wa root (this species) and being sold in the UK as a remedy for eczema, actually contained 0.013% clobetasol propionate, a semi-synthetic corticosteroid that is not known to occur naturally. 150 species are found in tropical regions. The fruits (burrs) possess hooked spines, which cling to the wool of sheep (Watt & Breyer-Brandwijk 1962). The seeds stick on touch to clothes and animal skin.
This species can produce mechanical injury (Oakes and Butcher 1962). References
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