Dog fennel
Route Of Exposure
Other topics
Dog fennel is an aggressive native perennial herbaceous annual member of the Asteraceae (Composite) family native to south-eastern North America. The Asteraceae are one of the largest families of flowering plants with about 25,000 species. Twelve major tribes are recognised. Dog fennel is a member of the tribe which also contains Yarrow, Chamomile, Sage, Wormwood, Chrysanthemum and Tansy.
Dog fennel is primarily a weed of landscapes, nursery, and some agronomic crops that is found throughout the United States.
In Florida, USA, Dog fennel in particular is widespread and implicated as an important pollen. Dog fennel and groundsel bush (Baccharis sp.) pollinate simultaneously, and their pollens cross-react with ragweed.
Clinical Relevance
IgE-mediated reactions
Anecdotal evidence suggests that asthma, allergic rhinitis and allergic conjunctivitis are common following exposure to pollen from Dog fennel; however, no specific studies have been reported to date.
In Tampa, Florida, the major weed pollen season (May through Dec.) was reported to consist of Ragweed, Mexican tea, Pigweed, Dog fennel, and false nettle. A minor weed season (March through July) consisted of Sorrel and Dock.
Other reactions
Allergic contact dermatitis following contact with Dog fennel has been reported.
Cross-Reactivity
Cross-reactivity could be expected between species of the family Asteraceae. Dog fennel and groundsel bush (Baccharis sp.) are reported to cross-react with ragweed.
References
- Lewis WH, Vinay P, Zenger VE. Airborne, and Allergenic Pollen of North America. Baltimore: Johns Hopkins University Press 1983:85-90,207.
- Phillips JF, Jelks ML, Lockey RF. Important Florida botanical aeroallergens. Allergy Asthma Proc 2010;31(4):337-40.
- Bucholtz GA, Lockey RF, Wunderlin RP, Binford LR, Stablein JJ, et al. A three-year aerobiologic pollen survey of the Tampa Bay area, Florida. Ann Allergy 1991;67(5):534-40.
- Menz J, Winkelmann RK. Sensitivity to wild vegetation. Contact Dermatitis 1987;16(3):169-73.
- Paulsen E, Andersen KE, Hausen BM. Sensitization and cross-reaction patterns in Danish Compositae-allergic patients. Contact Dermatitis 2001;45(4):197-204.