Parthenium hysterophorus: Allergy causing plant

Parthenium hysterophorus is also known as carrot weed or Congress grass. It belong to the family of plants whose other members include sunflower and chrysanthemum. Parthenium hysterophorus is neither ornamental nor edible plant. The plant grows to the height of 3 to 5 feet and bears white flowers. The flowering starts in spring season and continues for six to seven months. The plant is found in Argentina, Brazil, Mexico, States of Texas & Minnesota of USA, West Indies, India, Pakistan and Bangladesh. Profuse growth of the plant could be seen in many cities in India. Direct contact with plant causes skin allergy to more than 50% individuals. The skin allergy caused by Parthenium hysterophorus or Congress grass may manifest as generalized eczema affecting hands, face, eyelids, neck and later arms and torso. Allergy is must in summer months but occurs all through the year. Gardeners, farmers and those engaged in outdoor activities are most affected. Young persons of either sex may also become sensitized. Abundant growth of Parthenium hysterophorus in parks, along footpaths, play grounds, roadsides and even in the lawns of houses is the main cause of parthenium dermatitis in many developed and developing countries worldwide. Long-term administration of corticosteroids may sometimes be required for controlling the symptoms of parthenium dermatitis. Affected persons with associated complications and asthma may need hospitalization. Since the cattle do not relish the plant, hence it grows unchecked. The public participation is very essential for the eradication of this environmental menace. Parthenium hysterophorus plants need to be uprooted before the flowering phase and dumped underground or destroyed with chemicals or fire to get rid of this hazardous weed.