The days are getting longer, the temperature is rising, and home restrictions are being relaxed. Therefore, many of us spend more time outdoors. Hikers are hiking, mountain bikers are riding bicycles, and gardeners are gardening. Unfortunately, these activities are not without risks when it comes to your skin.Depending on where you live, you may inadvertently interact with Poison oak, poison ivy, or poison sumac Eventually a nasty, unsightly and very itchy rash will appear.
Why does poison ivy cause an itchy rash?
Genus Poison ivy (Formerly classified as Rus) can cause itchy rashes in many people who come into contact with them. The most common plants in this genus include poison ivy, poison oak, and poison sumac.
Although all three plants cause a rash, it is often called poison ivy dermatitis, especially east of the Rocky Mountains. It is commonly referred to as the Poison Oak in the western United States.The medical name of the condition is Poison ivy Dermatitis or sumac dermatitis. For readability, the term “poison ivy” will be used instead of repeating all three plants.
The rash is a type of allergic contact dermatitis (a classic type IV cell-mediated hypersensitivity reaction). It is triggered when the allergen in the oily sap resin urushiol is transferred to the skin. These allergens are small and can quickly penetrate into the outer layer of the skin called the epidermis. The presence of these allergens on the skin triggers an immune response that causes the rash.
It is important to know that urushiol is present in all parts of plants, including leaves, stems and roots. It can even be found in dead branches. Moreover, it can be transferred to clothes, pet fur, and other objects, such as gardening tools that come in contact with plants. The transfer of resin from these objects to human skin can also trigger an immune response.
Epidemiology of poison ivy dermatitis
Urushiol is highly allergic and many people are sensitive to it.In fact, it is estimated that about 50 million people are in contact each year Urushiol. Although anyone can be affected, Certain professionals Are at special risks, including,
- Firemen
- Forest worker
- Farmer
- gardener.
Poison ivy affects children and adults of all ages, although there is some evidence that allergic reactions can Decrease with age If people are not exposed repeatedly. In addition, it affects all races and skin types.
In the United States, poison ivy is more common to the east of the Rocky Mountains, and poison oak is more common to the west of the Rocky Mountains. Poison sumac is mainly distributed in the southeast of the country.
Plant identification: the key to avoiding contact
Genus Poison ivy People who like outdoor activities often meet. Therefore, it is important to learn how to recognize them. Their appearance may vary based on many factors, including:
- Plant growth cycle
- Region of the country
- Season of the year
- climate
The old adage “Three leaves, let them become “ Can help remember how to distinguish poison ivy and poison oak from other plants that are safe to touch.
1. Poison ivy
this Poison ivy The leaves of the plant grow in groups of three. The leaves are pointed, and the middle leaf may be slightly larger than the other two lateral leaves. They are green in spring, but turn red to orange in autumn. Poison ivy can grow as vines and shrubs. It may have a small cluster of white berries in the spring, which can last throughout the winter.
2. Poison Oak
Poison sumac It is more commonly found as a shrub, although it can sometimes be found as a vine. Its leaves are a bit like oak leaves, but also appear in groups of three like poison ivy. The leaves are green in spring, but turn orange to red in autumn. Poison oak flowers may be yellow or green, with yellow-green or white berries.
3. Poison sumac
Poison sumac Unlike the previous species, it is a woody shrub with 7-13 leaves arranged in pairs on the stem. The berries are also different and may be light yellow or cream in color. Poisons mainly grow in moist swamps or swamp areas.
Plant ID and photo reference): https://www.cdc.gov/niosh/topics/plants/identification.html
Poison ivy dermatitis rash
After exposure to the urushiol in vegetable oily juices, a red rash may appear within a few hours, especially if you have had poison ivy dermatitis before. In individuals who have not been exposed before, it may take up to 2 or 3 weeks for the rash to appear.
The rash appears as a red, intensely itchy bump or fluid-filled vesicles, usually arranged in a characteristic linear or striped pattern to determine where the plant touches the skin. If the oil is exposed to a piece of clothing or pets playing in the woods, the result is oil on the fur and the rash may appear more scattered.
***
Other articles by this author:
Sunscreen in the news: what is true and what is not
What to do if your hands become messed up because of too much washing
***
If it is not removed in time, the oily resin can spread to other parts of the body by scratching. In addition, the rash may spread over time because the rash will occur first in the areas where the allergen is most strongly exposed, and then in the areas with less exposure.
The rash itself is not contagious. This is not an infection, but an allergic reaction.
If left untreated, the poison ivy rash may last for several weeks. Those who have had a rash before tend to heal within a few days. Those who have never had a rash seem to take longer to heal.
Poison ivy control
1. Prevention
As in many situations, prevention is the best treatment:
- If possible, avoid using this plant and learn how to recognize poison ivy in all seasons and geographic changes. Remember: “Three leaves, go with the flow.”
- Wear protective clothing when gardening or hiking: high socks, long sleeves and pants.
- The use of barrier cream to prevent poison ivy rash is controversial. These topical preparations are usually used before exposure to prevent skin rashes.Reduced reactivity Small research Use 5% quaternion-18 bentonite emulsion (bentoquatam).
2. Remove resin as soon as possible after exposure
Although the rash itself is not contagious, if the oil is not removed, it is certainly possible to spread the oil from one person to another.
- Wash the exposed area with mild soap and water to remove residual oleoresin on the skin as soon as possible. Be sure to clean under your nails to remove any resin that may remain under your nails.
- Wash all items that may come into contact with plants or their oils, including clothes, garden furniture, gardening tools, gardening gloves, golf clubs, and even your pets. The oil does not have to come directly from the plant to cause the reaction.
3. Home remedies for mild poison ivy dermatitis
- Using over-the-counter hydrocortisone cream twice a day can relieve itching and reduce reactions.
- Oral antihistamines can also relieve itching.
- Apply calamine lotion to small blisters and oozing skin to help dry the rash.
- Epsom salt soaking can also help dry the rash.
- Do not open the blisters, as this may make the skin susceptible to infection.
- Cold compresses applied to the itchy area may feel comfortable.
If the rash is widespread or severe and affects the face or genitals, if the blisters ooze pus, or if you have a fever, seek immediate medical attention.
4. Drug treatment of poison ivy
- Topical corticosteroid therapy: High-efficiency corticosteroid preparations directly applied to skin rashes are the main method for the treatment of black wood dermatitis. In order to avoid skin atrophy, long-term use of these high-efficiency preparations in certain areas should be avoided, such as:
-
-
- Face
- genitals,
- Skin folds in the armpits and groin
-
- Systemic corticosteroid therapy: Patients with severe or extensive illnesses, or skin rashes involving the face or genitals, may benefit from oral steroid therapy. Although there is no standard dose, Clinical Experience It indicates that poison ivy may rebound when the treatment course is too short (for example, a 6-day packet of methylprednisolone). High-dose (1 mg/kg/day, maximum starting dose of 60 mg) oral prednisone treatment for 2-3 weeks can significantly improve poison ivy symptoms. For patients who cannot take the drug by mouth or cannot follow the dosing regimen, intramuscular injection is another treatment option.
- antibiotic It may be necessary if a bacterial infection of the underlying rash is suspected.
If it wasn’t poison ivy, what could it be?
- Allergic contact dermatitis from different kinds of plants: similar to the rash caused by this genus Poison ivy It may also be caused by other plants.Genus Compositae, Which includes flowering plants: daisies, sunflowers, dandelions and asters can also cause similar rashes.Genus Garlicaceae (garlic), Allium (Onion), and Myrtaceae (Tea tree) etc. can also cause a similar rash.
- Allergic contact dermatitis caused by substances other than plants: Allergic contact dermatitis may also be caused by non-plant allergens. For example, nickel and gold commonly found in jewelry are common causes of allergic contact dermatitis.
- After exposure to photosensitive plants and ultraviolet radiation, rashes may appear, with or without blistering phototoxic reactions.The most common plants that cause these types of reactions include Rutaceae (Lemon and lime) and Umbelliferae (Celery, wild parsnips and parsley.) Unlike poison ivy, these reactions only appear on skin exposed to the sun.
Poison ivy Dermatitis: the bottom line
Best to avoid contact Poison ivy The plant that causes this annoying rash. However, if you can’t or don’t, please act quickly and wash with soap and water to remove any resin from your skin. If the rash breaks out anyway (and is likely to break out), try home remedies first. But if the situation is more serious, seek medical attention.
View more articles Fayne Frey, MD
**Like our content? Sign up for our newsletter here**
Originally published on May 17, 2020. Updated by the author and republished on June 3, 2021.
Fayne Frey, MD
website:
https://FryFace.com/
Fayne Frey, MD, Is a board-certified clinical and surgical dermatologist, practicing in Signac, New York, specializing in the diagnosis and treatment of skin cancer. She is a nationally recognized expert in the effectiveness and formulation of over-the-counter skin care products.
She often gives speeches in many places, attracting audiences with her satirical observations on the skin care industry. She has consulted for several media, including NBC, USA Today and Huffington Post. She also shared her expertise on cable TV and major TV outlets.
Dr. Frey is FryFace.com, An educational skin care information and product selection service website that clarifies and simplifies the overwhelming selection of effective, safe and affordable products encountered in the skin care channel.
Dr. Frey graduated from Weill Cornell School of Medicine and is a member of the American Academy of Dermatology and the American Academy of Dermatology.
