Toxicodendron dermatitis is an allergic contact dermatitis (allergic phytodermatitis) that occurs from exposure to urushiol, a skin-irritating oil produced by members of the plant genus Toxicodendron. In North America, this includes poison ivy, poison oak, and, much less frequently, poison sumac.
How do you treat Toxicodendron exposure?
The initial treatment of toxicodendron dermatitis is to wash the affected area as soon as possible after exposure. Washing exposed areas with copious amounts of water within 20 minutes of exposure has been shown to reduce reactivity. The efficacy of washing appears to decrease over time.
What causes Rhus dermatitis?
Rhus dermatitis can be caused by poison ivy, poison sumac, or poison oak. The oil on the leaves, roots, and stems contains urushiol, a highly allergenic compound that can cause a type IV hypersensitivity reaction. Allergic persons are sensitized to the compound before reacting to the oil.
How do you treat Rhus dermatitis?
In patients with severe rhus dermatitis, oral prednisone should be tapered over two to three weeks because rapid discontinuation of steroids can cause rebound dermatitis. If treatment fails and the diagnosis or specific allergen remains unknown, patch testing should be performed.
How do I know if I have poison oak?
Once absorbed by the skin, poison oak can induce severe itching, redness, and swelling, followed by small or large blisters on the skin. The onset rash may appear on any part of the body after a short incubation period. However, the rash itself generally does not spread, and it is not contagious between individuals.
Does poison ivy swell up?
Poison ivy is a toxic plant that’s commonly found throughout most of the continental United States. Upon contact with human skin, poison ivy often causes a rash, known as contact dermatitis. (1) This rash may develop into increased redness, swelling, and blisters, which are often itchy or painful.
How do you describe poison ivy rash on a physical?
The symptoms most often include a red, bumpy, itchy rash with fluid-filled blisters. The blisters break open, ooze fluid, and then crust over. The area of skin may also be swollen. Swelling can mean the allergic reaction is more severe.
What does sumac look like on the skin?
A rash from poison ivy, oak, or sumac looks like patches or streaks of red, raised blisters. The rash doesn’t usually spread unless urushiol is still in contact with your skin.
What dies poison sumac look like?
All poison sumac leaflets are oval-shaped with smooth edges and pointed tips. They’re a hairless light to dark green in spring and summer, with a noticeable line down the center and fainter veins extending toward the edges.
Why does my poison ivy keep spreading?
It may seem like the rash is spreading if it appears over time instead of all at once. But this is either because the plant oil is absorbed at different rates on different parts of the body or because of repeated exposure to contaminated objects or plant oil trapped under the fingernails.
How does contact dermatitis look like?
Contact dermatitis can appear as an itchy, red rash. In this photo, the irritation is likely due to a watchband or to soap residue trapped beneath the band. Contact dermatitis is a red, itchy rash caused by direct contact with a substance or an allergic reaction to it.
Where should you not use hydrocortisone cream?
It can make some skin problems worse like impetigo, rosacea and acne. Only use hydrocortisone skin treatments on children under 10 years old if a doctor recommends it. Creams you can buy are not supposed to be used on the eyes, around the bottom or genitals, or on broken or infected skin.
What is the difference between contact dermatitis and allergic dermatitis?
Atopic dermatitis and contact dermatitis are two common types of eczema that are often confused. While they are both inflammatory skin conditions that share similar symptoms, their causes are different. Atopic dermatitis is an internal skin condition, whereas contact dermatitis results from external factors.
What poison oak rash feels like?
The AAD notes that a person can expect the following: An intense itch at the area where the rash will appear. An itchy, blistering rash that appears shortly after the itching begins. Blisters that may open and leak before crusting over.
Is Benadryl good for poison oak?
Smearing on hydrocortisone or other topical corticosteroids will help suppress the itching and give temporary relief, but it does little to hasten the drying up of the rash. Similarly, taking an oral antihistamine, such as Benadryl, can help with the itching quite a bit, but it doesn’t speed up resolution of the rash.
What’s the difference between poison ivy and poison oak rash?
A poison ivy rash will swell and itch, and it may form blisters. The rash often appears in a streak following the direction the plant brushed against the skin. A poison oak rash could take up to a week to appear. Poison oak causes swelling with itchy, red rashes that may blister.