Poison oak rashes are highly similar to rashes from poison ivy and poison sumac. All these three plants contain a sticky, oily resin called urushiol. Urushiol can be found in the plant’s leaves, stems and roots. It can remain active even upon adherence to other objects, such as clothing, equipment, tools, etc. and even in dead plants. Exposure to poison oak, whether directly or indirectly, can cause an allergic contact dermatitis causing rashes. Although, there have been reported cases where exposure to urushiol from poison oak did not cause skin reaction.
Poison oak rashes and fluids from blisters are not generally contagious and do not typically spread from person to person. It is only passed on to another person by exposure to the oil from the victim’s skin or shirt. Majority of the cases of poison oak rashes are not serious and can be managed at home even without medical treatment. For severe, extensive, or facial and/ or groin rashes, seek medical care as prescribed medicines may be necessary for treatment.
As always, prevention is better than cure. If poison oak is found nearby, avoid it. Poison oak (Toxicodendron diversilobum) is a shrub that sometimes appears as a vine. It looks like the leaves of poison ivy with a leaf containing three leaflets forming the “hairs.” Although it is quite rare in Canada, it is found in some parts of Vancouver Island and neighbouring islands.
What Causes Poison Oak Rashes?
There are several ways to be exposed to poison oak. Poison oak rashes can be obtained the same way poison ivy and poison sumac rashes are acquired.
- Direct touch
- Direct contact with the leaves, stem or roots
- Indirect touch
- Exposure to urushiol by touching objects that are contaminated
- Inhalation
- Burning of the parts of the plant leading to smoke inhalation and irritation of the nasal passages and lungs
What are Signs and Symptoms of Poison Oak Rashes?
Signs and symptoms of poison oak rashes are very similar to those of poison ivy and poison sumac. The severity of the rashes depends on the amount of urushiol that is exposed to the skin. It usually takes 12-48 hours after exposure for symptoms to manifest, that peak within 4-7 days and typically lasts for one to three weeks.
- Extreme itchiness
- Red, patchy rashes in the area where the oil came into contact with the skin that usually appear in a straight line
- Fluid-filled blisters
How is First Aid Given to Treat and Manage Poison Oak Rashes?
First Aid treatment for poison oak rashes is the same for treatment of poison ivy and poison sumac rashes. To give first aid poison oak, the following steps are recommended:
- Meticulously wash the skin with soap and warm water. Perform this as soon as possible as this may prevent the oil from entering the skin.
- Use a brush to clean under the fingernails to remove plant oil and avoid spreading to other parts of the body.
- Immediately remove clothes and shoes as it may contain urushiol. Wash clothes and shoes with warm water and soap.
- Apply cool compress to the skin and wear light clothing. Avoid sweating as it can worsen itching.
- To minimize itching and blistering, apply calamine lotion and hydrocortisone cream. Also, bathing in lukewarm water with an oatmeal bath product may also reduce itching. If these products do not work, antihistamines may be given.
- Bathe animals that may have come into contact with the oil to remove it.
Disclaimer: This article should not be substituted for medical diagnosis or medical advice. These hints are for information purposes. To learn how to treat poison oak rashes, enrol in first aid courses.