THURSDAY, Feb. 10 (HealthDay News) -- For some people, a simple day of gardening is not without its perils.

Mere contact with a range of common plants can bring on mild to severe skin reactions, an expert warns.

"While most of the skin reactions resulting from direct contact with a hazardous plant are more of a nuisance than anything else, there are some instances where the reaction can affect the entire body and pose a potentially more serious risk," Dr. Julian J. Trevino, an associate professor of dermatology at Wright State University Boonshoft School of Medicine in Dayton, Ohio, cautioned in a news release from the American Academy of Dermatology.

"People who are allergic to plants or have sensitive skin that is prone to eczema or atopic dermatitis may experience more severe or long-lasting effects that require medical attention," he explained.

Trevino was scheduled to discuss the issue at the American Academy of Dermatology annual meeting this week in New Orleans.

Troublesome plants include the so-called "stinging nettle." The plant's sharp hairs produce irritants that can provoke a usually mild hive outbreak after brushing up against it. The outbreak typically subsides within a few hours.

In addition, people susceptible to eczema or who handle food frequently can get hives from some fresh fruits and vegetables, herbs, nuts, shrubs and grasses. Severe reactions can spread beyond the skin and cause dangerous swelling of the throat, lungs and gastrointestinal tract.

Cacti and prickly pear plants are another concern, Trevino said. When the prickly spines pierce the skin, it can cause itching and a rash or even a staph or fungal infection if the spines are laced with bacteria or fungus.

The best known problem plants are poison ivy, poison oak and sumac. About half of the population is allergic to the sap, called "urushiol," and will get a rash following contact. But Trevino cautioned that when such plants are "injured," the sap can get released and spread to otherwise harmless plants in the vicinity.

"That means that you can develop poison ivy if you pet your dog after he has come in contact with the plant," he noted, "or if you touch a gardening tool or piece of clothing that has come in contact with poison ivy. Even airborne contact with urushiol is possible, especially in the fall or winter when these poisonous plants are burned among other brush and particles of urushiol are released into the air. If these airborne particles land on your skin or you inhale them, you can get a widespread rash and severe irritation in the respiratory tract."

To treat poison ivy, rinse the affected area, soak with products containing aluminum acetate or use topical creams containing calamine or steroids.

To reduce risk, when working in the garden, wear protective clothing and vinyl gloves, cover exposed skin with a barrier lotion that contains quaternium-18 bentonite and make a effort to avoid poisonous plants, Trevino advised.

More information

For more on skin exposure risk, visit the U.S. National Library of Medicine.