Dermatologist Houston - Patient Portal
New Patients: 281 771-0494 Existing Patients: (281) 395-7770
Katy Location

22028-C Highland Knolls
Katy, TX 77450 | Get Direction

Houston Location

St. Joseph's Professional Building. 2000 Crawford, Suite 1530, Houston, TX 77002 | Get Direction

Dr W save me I had so much discoloration and under my eyes look like they were burnt I am so grateful my skin like a 80% better thank you Dr Weaver !

Poison Ivy/Poison Oak/Poison Sumac

What are Poison Ivy / Poison Oak / Poison Sumac?

These are common plants, which produce oils that cause severe skin reactions in many people. Areas of the skin that come into contact with these oils become inflamed, itchy, and red with small blisters. Poison oak is most commonly found in the western and southeastern United States, while poison ivy is found in eastern regions. Common symptoms include:

  • Small hives or bumps.
  • Oozing, fluid-filled blisters.
  • Intense itching.
  • Streaked or red areas where the plant contacted the skin.


Poison oak, ivy, or sumac rashes are classified as contact dermatitis, which encompasses most allergic skin reactions. All of these plants secrete an oily substance called urushiol, a common irritant to human skin. Even a small amount can be absorbed by the skin and cause a severe reaction. Urushiol is a sticky substance that does not dry, making it cling to clothing and objects.

You may develop a rash from:

  • Directly touching any part of the plant.
  • Transferring urushiol from one area to another through skin contact.
  • Inhalation of smoke if the plant is being burned.
  • Touching a pet or object that has contacted a plant.


The best way to prevent this rash is to avoid touching poison oak, ivy, or sumac.

  • You should familiarize yourself with the appearance of these plants so that you can recognize and avoid them.
  • If any of these plants sprout in your yard, remove them promptly and carefully.
  • Clean any objects that have contacted these plants.
  • Be diligent in watching for them when outdoors.
  • Use a barrier skin cream.
  • Immediately clean any skin that you believe may have touched any of these plants.

Treatment options

If you have touched poison oak, ivy, or sumac a rash is likely to develop within 48 hours. In most cases, it will resolve naturally in two or three weeks. At-home therapies, such as over-the-counter hydrocortisone creams, antihistamines or oatmeal baths and can help control itching. Your doctor may prescribe an oral or topical steroid medication if the rash becomes severe.

If you have concerns about poison oak, ivy, or sumac rash, call Dr. W Dermatology at 281 771-0494 and schedule an appointment. We will be happy to see you at our Katy or Houston office.