Poison Oak Rash


What is Poison Oak Rash?

The western poison oak plant or Toxicodendron diversilobum (scientific name) appears as a leafy shrub with leaves having 3-9 separate leaflets that are about 1-4 inches long. The plants can grow up to 6 feet in shady areas and releases oil named. When a person comes into contact with the plant, the skin absorbs the allergen which may resultin a rash. Thus, contact with the leaves or stem of the poison can trigger an allergic reaction that leads to poison oak rash.

poison oak rash pictures

Image Source: en.wikipedia.org

How does poison oak affect the body?

Contact with oil sap present in the leaves, stem, roots, berries, flowers and fruits can cause skin irritation. The intensity of the reaction may range from severe to moderate. Broken plant parts that release oily resin toxicondenrol may cause the allergy as it contains the toxic chemical urushiol. This substance is difficult to wash off as resin does not dissolve in water.


  • Direct contact: Physical contact of an individual with the leaves, stem, berries, roots or other parts of the plant may cause an allergic reaction. The reaction is severe in cases where there is direct contact between the plant and the person’s skin.
  • Burning the plant: Poison oak produces a resin that causes an allergic reaction when a contact is made. However, burning the plant also releases smoke that contains urushiol; which is the allergy-causing toxin. The smoke can hence result in irritation of the nasal and air passages of the body.
  • Contaminated objects: Poison oak produces a resin that does not dissolve in water and it cannot be washed away. Objects such as clothes, shoes, and other articles that are contaminated can transfer its effects to the individual who comes into contact with the objects. Moreover, the resin can cause an allergy even after years of remaining on an object.


  • Signs appear within 1 to 6 days of exposure
  • Stinging
  • Itching
    poison oak rash images

    Image Source: en.wikipedia.org

  • Minor skin irritation
  • Initially, bumps appear, then change into blisters that ooze liquid and finally dry up forming crusts
  • Appears in places where the skin is thinner like the neck, wrists & ankles
  • Skin inflammation
  • Burning sensation
  • Red rashes in striped formation
  • Headache
  • Nausea
  • Fever
  • Swollen lymph nodes
  • Swelling of the face and eyes
  • Difficulty in breathing
  • Problem in swallowing
  • Rashes on the genitals

How does the rash spread?

In case of blister formation, there may be a liquid that oozes out of them. Contact with this liquid cannot spread the infection. If people keep themselves clean and wash thoroughly after contact with the plant, they may be able to avoid the allergic reaction. However, scratching the rashes with nails may cause the toxin to remain in the nails for a long time that could lead to the development of the rashes.

poison oak rash photos

Image Source: en.wikipedia.org

Poison Oak Prevention

  • Learn to identify the plant to come into contact with it
  • Avoid areas where poison oak grows
  • Wear full sleeves and long trousers to avoid any contact with parts of the plant
  • Restrain pets from going into areas where these plants grow to avoid the resin from sticking to their fur
  • Do not burn the plant as the smoke can irritate the nasal passage and lungs
  • Clean yourselves and pets thoroughly after returning from outings to avoid allergies


The following people are more likely to develop poison oak rash:

  • Construction workers
  • Farmers
  • Gardeners
  • Foresters
  • Hikers and trekkers


  • Physical examination
  • Rash must cover at least 1/3rd of the body
  • Checking for signs of bacterial infection
  • Redness and pus formation

Poison Oak Rash Treatment

  • Showering: Using lukewarm water to shower after coming into contact with poison oak plant can help to limit the chances of developing the rash. If the person can clean himself/herself thoroughly within an hour of the exposure, chances of the rash can be lowered considerably. The best way to start with this is to make sure to rid the nails, hands and feet of any dirt.
  • Cold compress: People often report a burning sensation at the site of the rash. Applying a cold compress may be able to limit the burning sensation. Ice packs could be used to treat such cases, but people must make sure not to apply the ice to the skin directly to avoid any damage to the skin.
  • Soaking in cool water: Immense itching and irritation accompany such rashes. Soaking the affected region with cool water helps to alleviate these issues.
  • Over the counter products: Application of calamine lotion or hydrocortisone creams could help to reduce the itching associated with the rashes. Alleviating the itching also prevents the spread or worsening of the infection due to the use of nails.
  • Medication: Allegra, Zyrtec and Benadryl are some oral histamines that reduce the itching and inflammation of the rash. Corticosteroids can also be given to limit the progress of the rash where a lot of blisters have formed. Antibiotics are also given to tackle any infection. Topical diphenhydramine is a medication that can reduce the inflammation but may cause redness and soreness as its side effects.

When to visit a Doctor?

A person who shows the symptoms mentioned above after coming in contact with the plant must consult a doctor immediately to avoid further complications. An individual must seek medical help in the following circumstances:

  • Problems in swallowing
  • Swelling of the tongue
  • Rash covers most of the body, including the face & the genitals
  • Swelling of the eyelids to the extent that causes the eyes to close
  • Toxin is inhaled and there is trouble in breathing due to irritation in the lungs and nasal passage

Poison Oak Rash Pictures:

poison oak rash pictures 1

Image Source: en.wikipedia.org



poison oak rash pictures 2

Image Source: en.wikipedia.org



poison oak rash pictures 3

Image Source: en.wikipedia.org


poison oak rash pictures 4

Image Source: en.wikipedia.org


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