Safeguard turning to threat

Latex can cause serious reactions - even death, writes John Hardie.

Latex can cause serious reactions - even death, writes John Hardie.

Earlier this summer, the Great Western Hospital in Swindon was given five months by the British Health and Safety Executive to improve systems for controlling exposure to latex, after an employee suffered a serious reaction to it.

This is not an isolated occurrence of an incident which can lead to anaphylactic shock and, in some cases, death. It's becoming more common among healthcare staff and their patients.

It is suspected that the rise in such reactions follows the dramatic increase in the use of rubber gloves as a means of preventing the transmission of infectious diseases. Studies on the relationship between rubber gloves and allergic reactions began about 20 years ago. This corresponds with the first widespread use of gloves in health facilities to avoid the transmission of HIV/AIDS.

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Not all of the factors in rubber latex are known which induce allergic reactions. However, the symptoms may vary: from itchy skin patches, to rashes, blisters and peeling skin, to running eyes and nose, extensive swellings, asthma and anaphylaxis. The last may result in death.

An article in the August 12th, 1993 edition of the Chicago Tribune suggested that an increasing number of patients were developing whole body reactions to latex with responses such as asthma and anaphylaxis becoming more common. The US Food and Drug Administration is aware of at least 16 deaths possibly being attributed to latex allergies, mainly from gloves and other latex-containing medical devices, such as catheters.

Allergic responses to latex may occur a few minutes after contact, or be delayed for up to 48 hours. Typically, the severe life-threatening responses, such as asthma and anaphylaxis, develop within an hour - necessitating prompt treatment. Fortunately, these serious reactions seldom occur on the first exposure to latex and usually are experienced by individuals who have a history of allergies. On the other hand, a person may have numerous uneventful contacts with latex rubber but the next one induces an allergic reaction.

Other sources of latex exposure could be from household rubber gloves, condoms and even rubberised baby comforters. Another possible source is the powder which lines many rubber gloves.

Today, it is commonplace for dentists and their nurses to wear rubber gloves principally to avoid the transmission of bloodborne infections, such as HIV/AIDS and hepatitis B. The latter is unlikely to be spread in dentistry as most clinical staff have been vaccinated against hepatitis B.

According to the Centres for Disease Control (CDC) in Atlanta, Georgia, the last transmission of hepatitis B in dental practice occurred in 1987. The CDC has stated that no transmission of HIV/AIDS associated with dental treatment has been reported since 1992. Indeed, as recently as December 2003, the CDC has indicated that the majority of dental healthcare personnel infected with a bloodborne virus do not pose a risk to patients, because such staff do not perform activities meeting the necessary conditions for transmission.

All of these facts could be used to support the idea that the routine wearing of rubber gloves by dental staff may not be as necessary as was believed in the late 1980s and early 1990s. Yet, despite the allergic-inducing effects of latex, including the threat of anaphylaxis and possible death, dentists continue to use the gloves, something which is now expected by the general public.

Paradoxically, by wearing rubber gloves, dental staff could be increasing rather than decreasing the risk of disease transmission. If staff are allergic to latex and have acquired a weeping type of dermatitis, they could expose patients to infectious blood. This exposure may not be avoided by latex gloves, all of which have minute holes and are not 100 per cent leak-proof.

Whether gloves are worn or not, not all dental procedures have the same risks of spreading bloodborne infections. Routine examinations, the taking of X-rays and impressions, denture fittings and adjustments, and most orthodontic treatments are low-risk activities.

In consideration of possible allergic reactions it is reasonable to question whether dental personnel should wear rubber gloves while delivering these low-risk procedures.

Perhaps, after consultation with patients, the use of latex gloves could be restricted to dental extractions, some gum treatments and certain aspects of root canal therapy. In any case, it would be wise for dental patients who have allergies to ensure that this is on record.

There are alternatives to the traditional latex gloves - powder-free gloves, non-latex nitryl or vinyl gloves, and hypoallergenic gloves. However, an increase in their use might be accompanied by, as yet, undetermined harmful side effects.

It is not known what measures the Great Western Hospital has taken to reduce latex exposures among its employees and patients. If the exposures are related to the excessive use of rubber gloves, an old-fashioned technique might be in order.

Experience has shown that the best, safest and cheapest method of avoiding the spread of infectious diseases is simple handwashing. If all medical, nursing and dental staff did this before and after clinical procedures, infections would decrease, as would the risk of latex allergies.

Dr John Hardie is clinical director, community dental services, DownLisburn Trust, Northern Ireland. The views expressed are his own.