Summary about Disease
Poison sumac dermatitis is an allergic skin reaction caused by contact with the oily resin called urushiol, found in the poison sumac plant. This resin triggers an immune response in most people, leading to a characteristic itchy, blistering rash. The severity of the rash varies depending on the amount of urushiol exposure and individual sensitivity.
Symptoms
The symptoms of poison sumac dermatitis typically include:
Intense itching
Redness
Swelling
Small blisters that may leak fluid
Raised bumps or streaks where the plant touched the skin
Causes
The primary cause of poison sumac dermatitis is direct or indirect contact with urushiol, the oily resin found in poison sumac plants. This can occur through:
Touching the plant directly
Touching contaminated objects (clothing, tools, pets)
Inhaling smoke from burning poison sumac (rare, but can cause a severe reaction)
Medicine Used
Treatment focuses on relieving symptoms. Common medications include:
Topical corticosteroids: To reduce inflammation and itching (e.g., hydrocortisone cream for mild cases; stronger prescription creams for more severe cases).
Oral corticosteroids: Prescribed by a doctor for widespread or severe rashes.
Antihistamines: To help relieve itching (e.g., diphenhydramine, loratadine).
Calamine lotion: To soothe and dry the rash.
Colloidal oatmeal baths: To relieve itching.
Topical anesthetics: To relieve pain.
Is Communicable
Poison sumac dermatitis itself is not contagious. The rash cannot be spread from person to person. However, urushiol oil can be spread if it remains on the skin, clothing, or other objects.
Precautions
Learn to identify poison sumac: Avoid areas where it grows.
Wear protective clothing: Long sleeves, pants, gloves, and boots when in areas where poison sumac may be present.
Wash exposed skin immediately: Use soap and water within 30 minutes of contact to remove urushiol.
Wash contaminated clothing and objects: Use hot water and detergent.
Use barrier creams: Products containing bentoquatam can help prevent urushiol from penetrating the skin.
Avoid burning poison sumac: The smoke can cause severe respiratory and skin reactions.
How long does an outbreak last?
The duration of a poison sumac outbreak varies:
Mild cases: 1-2 weeks
Moderate cases: 2-3 weeks
Severe cases: Up to several weeks
How is it diagnosed?
Diagnosis is typically based on:
Physical examination: The characteristic appearance and distribution of the rash.
Patient history: Exposure to poison sumac or similar plants.
Allergy testing: Rarely needed.
Timeline of Symptoms
Exposure: Contact with urushiol.
12-72 hours (or longer): Rash begins to appear (can be delayed up to several days if prior exposure was minimal).
Days 1-7: Rash progresses with increasing redness, swelling, and blister formation.
Days 7-21 (or longer): Blisters begin to dry and crust over; itching gradually subsides.
Several weeks: Complete resolution of the rash.
Important Considerations
Seek medical attention: If the rash is severe, widespread, near the eyes or mouth, or accompanied by fever.
Secondary bacterial infection: Can occur if blisters are scratched and broken; seek medical attention if signs of infection are present (increased pain, redness, pus).
Urushiol sensitivity: Can increase with repeated exposure.
Cross-reactivity: People sensitive to urushiol may also react to mangoes (the peel), cashews, and Japanese lacquer.