ASK THE DOCTOR: Poison ivy is the 3-leaf nuisance
By DR. JIM MITTERANDO
The Patriot LedgerQ. What do you recommend to prevent and treat poison ivy, which my child gets every summer? When it was real bad last year, the doctor put him on steroid pills. Is this safe?
A. Poison ivy, a climbing vine commonly found in New England, is one of several plants that causes itchy, blistering skin rashes. Poison sumac, a shrub found in wetlands is less common. The third plant, poison oak, generally is found in the Southeast and West.
To protect yourself from the aggravation of poison ivy, remember this rhyme: "Leaves of three, let it be." Generally, that rule helps people identify poison ivy, which has three leaves per cluster.
Poison ivy can fool people because its appearance varies from region to region in the United States: In the West, poison ivy can resemble a shrub. In this area, poison ivy generally has glossy green leaves, both ovoid and pointy.
Its color usually varies with the seasons, too. Emerging leaves are red in the spring, turn green during the summer, and are various shades of yellow, orange, red, or bronze in the autumn. Older plants can produce small, round, hairless berry-looking fruit that looks green when growing and cream-colored when ripe.
Poison ivy, a terrible nuisance but rarely dangerous, is a local skin reaction to the plant's resin, which is located in the leaves, stems and roots; the rash appears several days to several weeks after contact with the plant. Reaction, though, may be prevented if the resin is washed off with soap and water within 15 minutes of exposure.
The rash, initially red, bumpy, and extremely itchy, eventually can produce oozing blisters and often emerges on body parts at different times, up to a week apart. This delay misleads people into believing that the rash has spread and is "contagious." Both untrue. In fact, by the time the rash emerges, the plant resin no longer is on the skin.
Once the plant resin is washed from the skin, it cannot be spread to others. The resin, though may still be on clothing, boots or the family pet.
Even scratching or touching oozing blister fluid cannot spread the rash to body parts or another person.
Scratching, though, exacerbates the itch, prolongs the rash and could cause a skin infection. If untreated, the rash may last several weeks, but eventually will go away. Treatment with prescription steroid creams will provide quicker relief. Over-the-counter hydrocortisone creams are too weak to be of much use against this problem. Stronger steroid creams, such as Triamcinolone, Betamethasone and Fluocinonide, work better to reduce the rash and itching.
Apply weaker steroid creams to more sensitive facial skin.
Covering, oozing blisters with wet, cool wash cloths will help them dry up faster. To treat excessive oozing, soak the wash cloth in water containing Burow's solution, then apply to the blisters.
Most over-the-counter treatments are not helpful. Calamine lotion (the "pink stuff") makes a mess and does not relieve itching much after it has dried. Oatmeal baths just produce a ring around the tub and do not cure the rash. Benadryl and Caladryl lotions occasionally can cause an allergic rash and are not recommended.
Benadryl pills and other antihistamines, such as Chlortrimeton, Tavist, Allegra, Claritin and Zyrtec, help to reduce the itchiness, but do not shorten the rash's duration.
Oral steroid pills, such as Prednisone, become an option if the rash either is so dispersed that treating it with creams is impractical or if it is unresponsive to steroid creams.
Developing poison ivy around their eyelids worries people, but the condition does not affect vision.
When necessary, oral steroids are taken for 10 to 14 days. The dosage is slowly reduced to avoid a rebound rash. Oral steroids, generally safe when taken short term, do have side effects, including jitteriness, insomnia, increased appetite and bloating.
I prefer to treat poison ivy with topical creams and avoid systemic drugs, but do not hesitate to prescribe steroid pills when the rash is widespread.
To prevent plant resin from contacting skin, wear long sleeves and pants when possible and practical.
Carefully remove all exposed clothing and wash it. People unable to avoid contact with poison ivy may want to consider applying a barrier cream such as IvyBlock (bentoquatam). Even with such protection, you need to wash off exposed skin immediately.
Wear gloves when handling poison ivy in the yard or garden and then wash them when finished. Once they have taken root, which requires only one year, poison ivy plants are difficult to eradicate because they are quite resistant to herbicide sprays. One can pull poison ivy off tree trunks, sever the plant at the base, and bury the plant parts, but burning the debris can cause severe airborne allergic reactions and should never be done.
Dr. Jim Mitterando is a family doctor at Health Care South/Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.
Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA 02269-9159, or by E-mail to his attention at features@ledger.com.
Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.
Copyright 2001 The Patriot Ledger
Transmitted June 26, 2001