Latex allergies trigger symptoms in millions of sensitive people who encounter these allergens at home, on the job or during medical procedures. Symptoms are often similar to those caused by hay fever but can also include skin reactions. In rare instances, they can be life-threatening.

Latex is a milky sap produced by rubber trees in Africa and Southeast Asia. It is used in many products because it is flexible and relatively inexpensive. In addition, latex is used in most surgical and examination gloves because it provides an effective barrier against infectious organisms found in diseases such as AIDS and hepatitis B.

Most latex allergies are caused by products (e.g., gloves, balloons and condoms) that have been dipped in the material. During the manufacture of these products, a form is dipped into a vat of latex. After it dries, the product is washed and stripped from the form. If it is not washed thoroughly, a good deal of “free” latex remains. This can later trigger latex allergies or, in some cases, asthma symptoms. In some cases, reactions may be caused by additives added during the manufacturing process rather than to the latex protein itself.

Products made from molded latex – such as rubber stoppers and erasers – trigger fewer reactions. Synthetic rubbers, such as those that are butyl- or petroleum-based, do not cause people to react. These include products such as latex house paints and latex caulking.

Exposure to latex particles can occur through several routes, including:

• Standard skin contact
  
  
• Thin-skin contact (such as mouth, vagina, rectum)
  
  
• Mucous membrane contact (such as eyes, mouth, vagina and rectum)
  
  
• Inhalation
  
  
• Blood (such as when medical devices containing rubber are used in surgery)

Cornstarch is sometimes added to the inside of latex gloves to make them easier to slip on and off. This cornstarch can absorb latex proteins. When individuals slip their hands into or out of these gloves, they are snapped and the proteins can become airborne. The amount of latex that can become airborne varies greatly among different brands of glove.

There are several types of latex reactions:

• Immediate allergic reaction. Also known as latex hypersensitivity, this is the most serious reaction to latex and can result from any form of contact. Symptoms are similar to those of allergic rhinitis (hay fever), which in rare instances can progress to life-threatening anaphylactic shock.
  
  
• Contact urticaria. The most commonly occurring allergic reaction to rubber. It particularly affects healthcare workers sensitized to latex. Symptoms include itching and hives, which often appear within 15 minutes of donning latex gloves.
  
  
• Allergic contact dermatitis. A skin reaction to additives used in latex processing. Symptoms often appear one to two days after contact with the allergen. This delayed reaction can affect several areas of the body.
  
  
• Irritant contact dermatitis. A skin reaction to a chemical or other substance not caused by an allergic reaction. This is the least threatening type of latex reaction. Repeated exposures to chemicals in latex gloves cause irritant contact dermatitis.