The response is mediated by a series of cellular and molecular mechanisms. Parthenium dermatitis is an immuno-inflammatory disease, which upon contact sensitization by parthenium antigen propagates as a cell-mediated hypersensitivity immune response with early sensitization phase and a subsequent elicitation phase, if antigen exposure persists. įigure 1: Parthenium hysterophorus with white flower heads New outbreaks of the weed have been linked to movement of earth and transport of stock, fodder, and grain from Parthenium hysterophorus-infested areas. It grows in almost all types of soil, except near the seashore as the saline soil is not conducive to parthenium flowering.
It is an erect annual herb with alternate, deeply-dissected leaves, growing up to 2 m tall with much branched inflorescences bearing white flower heads. It is thought to have originated as a result of natural hybridization between Parthenium confertum and Parthenium Bipinnatifidum. Parthenium hysterophorus belongs to the subfamily asteroidae (tribe heliantheae). , Presently, Parthenium hysterophorus is the commonest cause of plant dermatitis in India and is responsible for nearly 40% of all patients attending contact dermatitis clinics. ,, , The authors have reported epidemics of parthenium dermatitis in Chandigarh and Delhi and in their adjoining states. Subsequently, many cases were reported from various parts of the country, namely Bangalore, Hyderabad, Madhya Pradesh, Uttar Pradesh, Haryana, and Himachal Pradesh. Since then, it has been widely reported across the Indian subcontinent. Ranade, Lonkar, and Jog were the first to report parthenium dermatitis at Pune, India, in 1968. during the 1950s and has become the "Scourge of India," producing an epidemic of allergic contact dermatitis. Parthenium is a native of tropical America and was introduced into Asia in cereal and grass seed shipments from U.S.A. Parthenium hysterophorus, a member of compositae family, is popularly known as "bitterweed," "feverfew," or "escobar amarga." In India, it is known as "Congress grass" or "Congress weed," which refers to the US congress (who allocated the shipment for Pune, India). Compositae dermatitis affects 0.7-1.4% of the general population and 4.5% of the occupationally-exposed groups. Genetic factors associated with susceptibility to parthenium dermatitis need to be studied.Ĭompositae plants are among the commonest causes of plant dermatitis and are the second largest family of flowering plants in the world. In future, we expect parthenium dermatitis to become less prevalent due to rapid urbanization and possible development of new biological methods to eradicate the parthenium. Management includes avoiding contact with allergen, managing dermatitis with topical corticosteroids/tacrolimus, and other immunosupressives like azathioprine. Patch testing with acetone or aqueous plant extract is the simplest way of confirming parthenium contact allergy. Contact sensitivity to parthenium is everlasting, and hence the disease runs a chronic course with exacerbation during summers. There is definite trend towards change from airborne pattern to chronic actinic pattern in natural history of parthenium dermatitis. In sensitized individuals, it can cause a spectrum of clinical patterns, such as classical airborne pattern, chronic actinic dermatitis-like presentation, mixed pattern dermatitis, exfoliative dermatitis, widespread dermatitis, and other rare patterns. The combined type IV and type I hypersensitivity to parthenium has been recently postulated. It is caused by airborne dry and friable plant particles including trichomes, and the most important allergens responsible for allergic contact dermatitis are sesquiterpene lactones. AbstractParthenium dermatitis is an immuno-inflammatory disease caused by Parthenium hysterophorus and is the commonest cause of plant dermatitis in India.
0 kommentar(er)
