Ragweed is a common plant in the United States, especially along the East Coast, and it produces large amounts of pollen in the spring. In many children, this pollen can lead to varying allergic reactions that include runny nose, sneezing, and itchy rashes. These allergies, termed hay fever, can be treated with antihistamines and by avoiding the pollen as much as possible.
Ragweed
Ragweed plants are typically found in wooded and rural areas. The warm and humid weather of spring triggers ragweed pollen release, with most pollen released in the early morning hours; breezes can carry the pollen for miles. In some children, ragweed pollen can trigger the immune system. Although it normally helps to protect the body against infections, the immune system can react strongly against pollen. These immune cells release large amounts of the chemical histamine, which is responsible for most of the symptoms of allergy.
Allergic Reaction
An allergic reaction to ragweed is termed "hay fever" and it is extremely common in children. According to the Asthma and Allergy Foundation of America, 75 percent of pollen allergies are due to ragweed. Common symptoms of hay fever include an runny and itchy nose, sneezing, headache and puffy nose. Ragweed pollen exposure can also cause a rash, though it is less common than hay fever. The appearance of the rash may be delayed by 1 to 2 days following exposure. Its appearance may vary from mild redness over the affected area, to a raised, red, itchy lesion that may seep fluid. The rash may last for 1 to 3 weeks following exposure.
Treatment
Treatment for ragweed-related allergies is symptomatic. In some children with rashes of unknown origin, patch testing, using various common allergens, may be needed to establish the diagnosis. Affected children should avoid further ragweed contact. A cold washcloth can be placed over affected areas to provide symptomatic relief. Lotions containing steroids reduce swelling and itchiness. In some cases, non-sedating antihistamines can be given by mouth.
Prevention
The most effective way to prevent the allergic reaction is to avoid exposure to ragweed. Children who are susceptible to ragweed should stay indoors during peak pollen seasons, especially in the early spring. In urban areas, the pollen is commonly present outside between 10 a.m. and 3 p.m. When venturing outdoors, clothing should minimize skin contact with the pollen. Immunotherapy, or allergy shots, may be considered in severe cases.
References
- Asthma and Allergy Foundation of America: Ragweed Allergy
- "Nelson Textbook of Pediatrics, 18th Edition"; Kliegman et al.; 2008
