While the percentage of people with latex allergy is rather low, many more are at risk due to prolonged, frequent exposure to latex. Screening potential patient latex allergy beforehand is critical, because diagnosis is still an imprecise science. How do you identify your at-risk patients? Here are five red flags to look for.

1. Occupational exposure to latex
Exercise caution with any patient who routinely wears latex gloves on the job or works in close proximity to people wearing latex gloves. Healthcare workers are No. 1 on the danger list for developing latex allergy. About 1-to-6 percent of the general population currently have active latex allergy, while the numbers range from 8-to-12 percent of healthcare workers.

Here's the problem: It doesn't always take direct skin contact with latex to trigger a reaction in someone with heightened latex sensitivity or allergy. People may also react by inhaling latex aerosol; merely being around non-allergic workers wearing latex gloves (especially powdered ones) can be enough.

When you interview patients pre-op, probe further if they tell you latex exposure is a routine part of their job. Find out if they have a history of rashes, itching, hives, and/or swelling on their hands. These may be signs of contact allergies (such as contact dermatitis or contact urticaria). Signs of potential latex aerosol reactions include patients who experience eye, nose or mouth irritation or have difficulty breathing.

Even if the patient has no history of moderate or acute reactions, you may not be in the clear. Different people have different thresholds to the proteins in latex. Some patients may never experience a contact and/or aerosol reaction - until a procedure in your OR.

2. Surgical and non-surgical procedure history
A patient's surgical history provides us some guidelines for determining risk level for latex allergy. Studies have shown two high-risk groups: patients who had frequent surgeries or invasive diagnostic procedures during infancy and patients who underwent radiological exams that used latex-rubber barium enema-retention balloons. Any patient with a history of anaphylaxis or shock during surgery should be considered high-risk, even if the reaction was not attributed to latex exposure.

You may also spot latex-sensitivity or allergy-warning signs in patients who report a history of itching, swelling or difficulty breathing after routine visits to a dentist, general practitioner, or specialist such as a gynecologist or proctologist.

3. Atopic patients
It's true that atopic individuals (people who produce the IgE antibody in large quantities) are generally more prone to latex allergy than non-atopic people. However, finding out if the patient is atopic is not as good as learning the patient's exposure history. Several studies show that only 2-to-3 percent of non-exposed atopic people test positive for latex allergy.

Still, be suspicious of reaction risks if the patient is atopic and has a history of exposure. As with occupational risks, a person may be atopic and not develop an allergy for years, or it can manifest suddenly.

4. Food allergies
Certain foods contain proteins similar to heivein (a protein found in the milky fluid from the rubber tree used to manufacture latex). Patients at risk for latex allergy sometimes are allergic to some or all of these foods. Symptoms may range from hives to itching or irritation of the lips and throat, or more severe allergic reactions.

5. Latex sensitivity in daily life
We're all exposed to latex simply because it is used in so many products we encounter. In most cases, if someone is not already sensitized or allergic to latex, these exposures aren't a problem. The contact or inhalational exposure is usually not sustained for a long time and the chances of developing latex sensitivity or allergy from these exposures alone are very slim.

However, you may find warning signs of a potential latex sensitivity or allergy by asking about potentially problematic exposures they've had in their personal lives. For example, ask if they've experienced shortness of breath after inflating a balloon. Perhaps they routinely have itching or swelling after condom use.

Keep in mind the aforementioned patient risk factors are just that; they predict the increased potential for a latex allergic reaction in your OR if you do not eliminate exposure. Without positive diagnostic tests, you won't know for sure, and it's unlikely the average facility will have reliable latex allergy diagnostic test results in hand. So remember - better safe than sorry.