(Daisy or Sunflower family)
- Chrysocoma tenuifolia Bergius
Kaalsiekte, a syndrome involving alopecia, severe diarrhoea, and also acute conjunctivitis, rhinitis, and keratitis occurs in kids and lambs whose mothers eat this southern African species during pregnancy (Steyn 1934, Watt & Breyer-Brandwijk 1962).
- Cichorium endivia L.
- Cichorium intybus L.
- Chicory, Succory
Both of these species is grown as pot-herbs; their blanched leaves are used in salads. The roots of C. intybus are the source of the chicory used as an additive to coffee (Coffea L., fam. Rubiaceae). Bonnevie (1948) reported contact dermatitis in persons engaged in the preparation of a coffee additive from C. intybus.
A grocer who had recurrent contact dermatitis of the hands and forearms was found to be contact sensitive to both C. endivia and C. intybus, and also to Lactuca sativa var longifolia hort. (the romaine lettuce). A positive patch test reaction to alantolactone, negative in controls, was observed (Vail & Mitchell 1973). Krook (1977) described four cases (3 female; 1 male) of occupational contact dermatitis from lettuce (Lactuca sativa L.). Two showed immediate vesicular reactions to lettuce, and two showed contact urticaria to both lettuce and endive which was confirmed by scratch testing. Cross-sensitivity variously to Ambrosia elatior L. (see Ambrosia artemisiifolia L.), Tanacetum vulgare L., Parthenium hysterophorus L., and Achillea millefolium L. was also found. Friis (1973) reported a case of a greengrocer who was contact sensitive to C. intybus and to C. intybus var foliosum hort. Tests in controls were negative. Other cases of occupational contact dermatitis from chicory, endive, and lettuce were described by Friis et al. (1975) and Lahti (1980). Malten (1983) described a case of a female cichory farm worker who suffered dermatitis of the arms, face, and V of the neck from September to April. Patch testing with the root and leaves of the Brussels Witloof cultivar confirmed the diagnosis. Malten also observed that the allergen (hapten) apparently penetrated rubber gloves.
A florist with chrysanthemum allergy gave positive patch test reactions (2+) to C. intybus and also to three other members of the Compositae (Hausen 1979).
Frain-Bell & Johnson (1979) observed positive patch test reactions to cichory in 8 from 55 patients with the photosensitivity dermatitis and actinic reticuloid syndrome.
Potentially allergenic guaianolides have been reported from Cichorium intybus.
- Cineraria L.
Fifty species are to be found in Africa and Madagascar. The genus is classified in the tribe Senecioneae, and is closely related to the genus Senecio L. into which very many species have been transferred.
The cineraria of florists, which is commonly grown for decorative purposes, is derived from Pericallis x hybrida B.Nord., of which many varieties and cultivars are known.
Of 302 persons tested with [an unidentified] cineraria leaf, 1.7% showed positive reactions. Fregert & Hjorth (1969) concluded that some species are marginal irritants.
- Cirsium Mill.
The genus of 150 species, which are found in northern temperate regions, is closely allied to the genus Carduus L. It is classified in the tribe Cynareae.
The spines of some species can cause mechanical injury. Transient papular urticaria can result from skin contact (Ross 1972) and conjunctival nodules from eye contact (Duke-Elder & MacFaul 1972b).
- Cirsium vulgare Ten.
- (syns Cirsium lanceolatum Scop., Cnicus lanceolatus Willd., Carduus lanceolatus L.)
- Black Thistle, Spear Thistle
Pammel (1911) records that this species can cause mechanical injury.
- Clibadium surinamense L.
14-Hydroxycostunolide, a potentially allergenic sesquiterpene lactone, has been reported from this species.
- Cnicus benedictus L.
- Blessed Thistle
The genus Cnicus L. emend. Gaertner, which is classified in the tribe Calenduleae, is monotypic. The blessed thistle is found in the Mediterranean region but is also cultivated as an ornamental plant.
Potentially allergenic sesquiterpene lactones have been reported from the plant. The spiny leaves may cause mechanical injury.
- Conyza Less.
The genus comprises some 60 species which are found in temperate and sub-tropical regions.
Bohlmann & Jakupovic (1979) could find no sesquiterpene lactones in C. pinnata Kuntze, C. obscura DC., or C. ulmifolia Kuntze.
- Conyza bonariensis Cronq.
- (syn. Erigeron bonariensis L., Erigeron linifolius Willd.)
Burry & Kloot (1982) consider that airborne dusts formed by the breakdown of senescent tissues of this and other species in the Compositae are the causative agents in Australian bush dermatitis. Burry (1979) described the case of a patient in South Australia with dermatitis from fleabane. Positive patch test reactions to ragweed (Ambrosia psilostachya DC.), Shasta daisy (Leucanthemum x superbum D.H.Kent), stinkwort (Dittrichia graveolens Greuter, syn. Inula graveolens Desf.), dandelion (Taraxacum officinale F.H.Wigg.), capeweed (Arctotheca calendula Levyn), Chrysanthemum morifolium Ramat., and alantolactone, as well as to fleabane flowers, stems and leaves, were obtained. Sertoli et al. (1978) reported allergic contact dermatitis to fleabane, Inula viscosa Dryander (see Dittrichia viscosa Greuter), and Salvia officinalis L. (fam. Labiatae) in a 65 year old male.
- Conyza canadensis Cronq. var canadensis
- (syns Erigeron canadensis L., Leptilon canadense Britton & A. Brown)
- Canada Fleabane, Canadian Horseweed, Fleabane, Horseweed, Fireweed, Colt's Tail, Mare's Tail, Mule Tail
This species has been reported to irritate the skin of persons who handle it (White 1887, Pammel 1911, Pope 1968) and the dust of the powdered leaf is also irritating (Watt & Breyer-Brandwijk 1962).
Lovell et al. (1955) observed strong (4+) patch test reactions to Leptilon canadense oil and to ragweed oil (see Ambrosia L.) in a patient with allergies to various tree pollen oils who presented with an airborne contact dermatitis. In an investigation of "weed dermatitis", one of 50 patients showed a positive patch test reaction to an extract of the plant (Shelmire 1939a). Patch tests carried out using the leaves of this species crushed in a small quantity of normal saline elicited no positive reactions in 7 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978).
The plant yields an oil of perfumery (Arctander 1960). Oil of fleabane or oil of erigeron derived from this plant is composed mainly of limonene, and is irritant to the skin and eyes, but less so than oil of turpentine (Watt & Breyer-Brandwijk 1962).
Bohlmann & Jakupovic (1979) could find no sesquiterpene lactones in this species.
- Coreopsis L.
Some 120 species are to be found in the Americas and tropical Africa. A few species are cultivated for their decorative flowers.
Frain-Bell & Johnson (1979) observed positive patch test reactions to the oleoresin from an unnamed Coreopsis species in 8 from 55 patients with the photosensitivity dermatitis and actinic reticuloid syndrome.
- Cosmos Cav.
The genus is classified in the tribe Heliantheae. Twenty five species are found in tropical and subtropical America and the West Indies. Several species, notably C. bipinnatus Cav. and C. diversifolius Otto are grown in gardens for their decorative flowers.
Sniffing a Cosmos flower caused symptoms of pollinosis in a patient who also reacted in this way to Tagetes (Biederman 1937).
- Cosmos bipinnatus Cav.
Becker & O'Brien (1959) reported four positive patch test reactions to this plant; clinical details were not given.
- Cosmos hybridus hort.
- Cosmos sulfureus Cav.
Costunolide, a potentially allergenic germacranolide, has been reported from these species.
- Cotula minuta G.Forst.
- (syns Centipeda minuta C.B.Clarke, Centipeda minima A.Braun & Asch., Centipeda orbicularis Lour., Myriogyne minuta Less.)
Centipeda orbicularis, when dry, causes irritation of the nasal mucous membrane (Maiden 1909).
- Cullumia setosa R.Br.
This species has been reported to contain α-terthienyl (Bohlmann et al. 1973), a phototoxic thiophene (see Tagetes L. below).
- Cyanopsis muricata Dostál
- (syns Amberboa muricata DC., Centaurea muricata L.)
Cynaropicrin, deacylcynaropicrin, and muricatin, three potentially allergenic sesquiterpene lactones, have been reported from this species.
- Cynara L.
The genus is classified in the tribe Cynareae. Fourteen species are found in the Mediterranean region east to Kurdistan. Both the cardoon (C. cardunculus L.) and the globe artichoke (C. scolymus L.) are grown in the vegetable garden for their edible parts - the leaf-stalks and midribs of the former, the fleshy bases to the scales on the flowerheads of the latter.
- Cynara cardunculus L.
- Cardoon, Wild Artichoke
Burry & Kloot (1982) consider that airborne dusts formed by the breakdown of senescent tissues of this and other species in the Compositae are the causative agents of Australian bush dermatitis.
Contact sensitivity to the leaf, flowerhead, and stem was observed in Australian bush workers who had "weed dermatitis". Cross-sensitivity to species of Arctotheca Wendl., Chrysanthemum L., Inula L. (see Dittrichia Greuter), Olearia Moench, and Xanthium L. was observed (Burry et al. 1973). Turner (1980) described a case in Australia of a 68 year old dry-flower arranger with recurrent facial dermatitis, the severity of which was exacerbated after collecting this species. Patch testing with this plant produced a 2+ reaction after 96 hours; 1+ reactions to Ambrosia psilostachya DC., Ixodia achillaeoides R.Br., and Centipeda thespidioides F.Muell. were also observed. All tests were negative in a control.
Cynaropicrin, a potentially allergenic guaianolide, has been reported from this species.
- Cynara scolymus L.
- Globe Artichoke
Dermatitis from artichokes was reported by Davezac (1908). Gougerot & Seringe (1938) found dermatitis among workers who cleaned artichokes to be common, affecting one person in five. Food-handlers, vegetable sellers, and a housewife have been affected by dermatitis of the hands, upper limbs, and face from contact with the plant (Sidi et al. 1950, Meding 1983). Positive patch test reactions to the roots and stem, negative to the leaves, were observed. Santori (1932) obtained positive patch test reactions with an ether extract. A woman who picked artichokes whilst scantily dressed developed a widespread linear bullous eruption (Burry et al. 1973). Artichokes have also produced contact dermatitis in market gardeners (Vallet 1964).
Burry & Kloot (1982) consider that airborne dusts formed by the breakdown of senescent tissues of this and other species in the Compositae are the causative agents in Australian bush dermatitis.
The plant yields cynaropicrin (Schneider & Thiele 1974) and other potentially allergenic sesquiterpene lactones.