Latin name: Taraxacum vulgare
Source material: Pollen
Family: Asteraceae (Compositae)
Common names: Dandelion, Common Dandelion
The genus Taraxacum is a member of the family Asteraceae, subfamily Cichorioideae, tribe Lactuceae. The Asteraceae includes Chrysanthemum, Dandelion, and Mugwort.
The Dandelion is a perennial weed that originated in Europe and Asia and is now naturalised throughout the world. It is particularly abundant in most of the northern hemisphere. In many countries such as Australia, Poland, Italy and Turkey it is considered a weed seriously interfering with agriculture.
Dandelion grows to a height of 0.5 m and a width of 0.3 m. Stems are hollow, very short and wholly underground, producing a rosette of leaves at the ground surface. The leaves are deeply toothed and 5 to 40 cm long.
Dandelion flowers in spring and early summer, sometimes with a secondary flowering in autumn. Flowering occurs for the whole year in warmer climates. The 2-3 cm in diameter flower heads are solitary at the end of naked, hollow stalks. Stalks can reach heights up to 60 cm. One head contains from 100 to 300 yellow ray flowers. The flowers have an unpleasant odour, are hermaphrodite (have both male and female organs) and are pollinated by insects. The plant is apomictic (reproduces by seeds formed without sexual fusion) and self-fertilising.
The seeds are brown and connected to white, feathery structures that are easily carried by the wind or by touch. The seeds ripen from May to June. A parachute of bristles aiding in dissemination tops Dandelion seeds. Seeds travel up to several hundred meters.
The Dandelion is an abundant weed found in lawns, meadows, fields, highways, waste places and the vicinities of railroads. It may also be cultivated.
The small tender leaves can be eaten as salad, the roots can be ground as a substitute for coffee (but are bitter), wine can be fermented from extracts of the flowers, and various parts may be used as medication.
Dandelion pollen may be found in herbal medications (1).
A 18 kDa Bet v 1 related-protein has been isolated from the root of the plant (2). Whether a similar protein exists in Dandelion pollen was not determined.
No allergens from this plant have yet been characterised.
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 Asteraceae (3).
Many patients found to be sensitive to Dandelion are likely to have been sensitised by other members of the Asteraceae (Compositae) family, such as the wind-pollinated Mugwort or Ragweed, due to a close botanical relationship. Cross-reactivity has been confirmed between sunflower and other Compositae pollens (Mugwort, Marguerite, Dandelion, Golden rod, and Short ragweed) by RAST and immunoblotting inhibition experiments. Mugwort pollen exhibited the greatest degree of allergenic homology (cross-reactivity) with sunflower pollen, whereas at the other end of the spectrum, Short ragweed showed fewer cross-reactive epitopes (4).
A study investigated the sensitisation and cross-allergenicity of Chrysanthemum, Dandelion, and Mugwort by reviewing the records of 6,497 respiratory allergic patients who underwent skin prick tests, and concluded that in individuals with respiratory disease, Chrysanthemum and Dandelion were frequently co-sensitised with Mugwort, and that these 2 species also showed extensive cross-allergenicity with Mugwort (5).
Anecdotal evidence suggests that asthma, allergic rhinitis and allergic conjunctivitis are common following exposure to pollen from Dandelion; however, few specific studies have been reported to date (5-7).
A Korean study investigated the sensitisation and cross-allergenicity of Chrysanthemum, Dandelion, and Mugwort by reviewing the records of 6,497 respiratory allergic patients who had been skin prick tested, and found that sensitisation to Mugwort, Chrysanthemum, and Dandelion occurred in 13.4%, 10.0%, and 8.5% of patients, respectively. Co-sensitisation to all three pollens was found in 5.2%. Some patients were monosensitised to 1 species (1.5% to Chrysanthemum, 1.4% to Dandelion, and 4.5% to Mugwort). The study concluded that in individuals with respiratory disease, Chrysanthemum and Dandelion were frequently co-sensitised with Mugwort, and that these 2 species also showed extensive cross-allergenicity with Mugwort (5).
Seasonal allergic contact dermatitis in a florist has been described (8).Other reactions
Contact dermatitis due to Dandelion has been described (9-12).
A 32-year-old atopic patient with allergic rhinitis developed a severe anaphylactic reaction following the ingestion of a pollen compound prepared in an herbalist’s shop. The patient was found to be sensitised to Artemisia vulgaris
, Taraxacum officinalis
or Salix alba
. All three were components of the pollen compound, in the ratio of 15% Taraxacum officinalis
, 5% Artemisia vulgaris
, and 15% Salix alba
. The allergen responsible for the reaction could not be identified with certainty, but the authors caution that a food-induced systemic reaction due to a pollen compound is possible (1).
Adverse reactions to pollen following ingestion have been documented in other studies. Immediate allergic reactions occurred in 3 patients following the ingestion of a health food known as ”bee pollen”. The bee pollen contained Dandelion pollen. In vivo and in vitro studies demonstrated that the patients were sensitive to several family members, rather than to insect-derived antigens (13).
Dandelion pollen in honey may also result in allergic reactions. Other pollen, e.g., from other members of the Compositae
family, may also result in allergic reactions. However, other possible causes for adverse reactions to honey include bee venom and the presence of bee pharyngeal glands and other bee body components. The authors caution that in individuals allergic to honey, primary sensitisation may be due to the honey itself, to airborne Compositae
pollen or even to cross-reacting bee venom components (14-15).
Ingestion of other parts of the Dandelion plant has also resulted in adverse reactions, attributed to the presence of sesquiterpene lactonespresent in the leaves and stems (16).
Compiled by Dr Harris Steinman, email@example.com
- Chivato T, Juan F, Montoro A, Laguna R. Anaphylaxis induced by ingestion of a pollen compound. J Investig Allergol Clin Immunol 1996;6(3):208-9
- Xu X-Y, Bewley JD, Greenwood JS. Cloning and characterization of an 18 kiloDalton protein in the roots of the perennial weed Taraxacum officinale Weber (Dandelion) which has allergen- and pathogenesis-related protein properties.
Plant, Cell & Environment 2000;23(11):1227
- Yman L. Botanical relations and immuno-logical cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
- Fernandez C, Martin-Esteban M, Fiandor A,
Pascual C, Lopez Serrano C, Martinez Alzamora F, Diaz Pena JM, Ojeda Casas JA.
Analysis of cross-reactivity between sunflower pollen and other pollens of the Compositae family.
J Allergy Clin Immunol 1993;92(5):660-7
- Lee YW, Choi SY, Lee EK, Sohn JH, Park JW, Hong CS. Cross-allergenicity of pollens from the Compositae family: Artemisia vulgaris, Dendranthema grandiflorum, and Taraxacum officinale. Ann Allergy Asthma Immunol 2007;99(6):526-33
- Syhaieva IA. Efficiency of specific immunotherapy in treatment of patients with seasonal allergic rhinitis. [Ukrainian] Lik Sprava 2006;(1-2):51-3
- Lavaud F, Jonvel AC, Fontaine JF, Sabouraud D,
Lebargy F. Les pollinoses de proximité ne sont-elles que des cas cliniques ? Revue de la littérature à propos de cinq observations / Pollinosis of proximity: Review of the literature and report of five cases Revue francaise d allergologie 2007;41(2):51-6
- Ingber A. Seasonal allergic contact dermatitis from Taraxacum officinale (dandelion) in an Israeli florist.
Contact Dermatitis 2000;43(1):49
- Paulsen E, Andersen KE, Hausen BM. Sensitization and cross-reaction patterns in Danish Compositae-allergic patients.
Contact Dermatitis 2001;45(4):197-204
- Lovell CR, Rowan M. Dandelion dermatitis. Contact Dermatitis 1991;25(3):185-8
- Poljacki M, Jovanovic M, Boza P,
Mimica-Dukic N, Petrovic A, Novovic Z. Is Vojvodina a risk area for contact weed allergies? [Serbian] Med Pregl 2005;58(3-4):123-6
- Jovanovic M, Poljacki M, Mimica-Dukic N, Boza P, Vujanovic Lj, Duran V, Stojanovic S.
Sesquiterpene lactone mix patch testing supplemented with dandelion extract in patients with allergic contact dermatitis, atopic dermatitis and non-allergic chronic inflammatory skin diseases.
Contact Dermatitis 2004;51(3):101-10
- Cohen SH, Yunginger JW, Rosenberg N, Fink JN.
Acute allergic reaction after composite pollen ingestion.
J Allergy Clin Immunol 1979;64(4):270-4
- Helbling A, Peter C, Berchtold E, Bogdanov S, Muller U. Allergy to honey: relation to pollen and honey bee allergy.
- Fuiano N, Incorvaia C, Riario-Sforza GG, Casino G. Anaphylaxis to honey in pollinosis to mugwort: a case report.
Allerg Immunol (Paris) 2006;38(10):364-5
- Lundh K, Hindsen M, Gruvberger B, Moller H,
Svensson A, Bruze M. Contact allergy to herbal teas derived from Asteraceae plants. Contact Dermatitis 2006;54(4):196-201