Porphyria Educational Services

PORPHYRIA EDUCATIONAL SERVICES BULLETIN
Vol. 2 No. 5                                         January 30, 2000
Focus: LATEX ALLERGY

        The overall incidence of latex allergy is unknown, but the
prevalence in the general nonatopic population is estimated to be less than 1 percent which
was cited in recent study in Michigan.

        In this study which was conducted in the city of Detroit, 1000 blood
donors were tested for immunoglobulin E (IgE) specificity for latex. The outcome
of the study cited  a 6.4 percent positive response, which seems to be a
much higher prevalence in the general population than had been indicated earlier.

        Latex allergy has had quite a history. Beginning in the fall of
1989,  the Food and Drug Administration (FDA) started receiving medical reports
of patients going into anaphylactic shock while receiving barium
enemas.  It was soon found  that the latex-cuffed enema tip was the cause
 of a total of 16 deaths.

        Increased awareness of latex allergy followed this episode.
Another gorup of patients at risk are spina bifida patients. These
 patients  are frequently exposed to latex from urethral catheterizations,
multiple surgeries, and ventriculoperitoneal shunt placement early in life.

        The prevalence of latex allergy in  porphyria patients ranges much
higher. Porphyria patients with cutaneous symptomology or those with MCS
exacerbation need to be especially aware of the problems with latex.

        The numbers  of latex allergy patients among health care workers
 is estimated between 5 to 10 percent.

         Workers in the latex-manufacturing industry are also at risk, with
one glove-manufacturing plant reporting a 3.7 percent prevalence of occupational
asthma based on positive skin-prick testing and spirometric data. Workers at
a latex doll-manufacturing plant were also found to be sensitized to latex
sensitization.

        Other persons are at risk, especially the police and
emergency medical personnel, food handlers who work in cafeterias and
fast-food restaurants, and sanitation engineers in various fields, all of
whom can wear latex gloves for prolonged periods.

        Patients with atopy have higher risk for latex allergy.

        The reasons for latex allergy has to do with the processing and
source of latex. Latex is the milky sap obtained by tapping the rubber
tree.   It is derived from the cells of the lactiferous system found in the
rubber tree.  The raw product is mixed with a preservative, such as
ammonia.  It is processed and it  concentrated.  Then the latex is shipped
 as a latex concentrate.

        Numerous chemical accelerators reduce the temperature and time
required. These accelerators can cause allergic reactions and are responsible for many
cases of contact dermatitis.

        Chemically, latex contains proteins, cis-polyisoprene, water, and
lipids. The proteins cause the severe immediate hypersensitivity reactions.
More than 50 different proteins have been implicated in the allergic
response, with up to a total of 240 different proteins found in latex. Latex
products are made either by pouring the rubber into molds or by forming a
coating in a dipped process, as is done with gloves, balloons, and condoms.

        Coated  or very soft rubber products appear to have the highest
content of latex proteins and, therefore, have the greatest allergenic potential.

        Systemic reactions to latex can result from exposure to latex
protein by various routes, including the skin, mucous membranes, inhalation, and
intravascular or internal tissue.

        Medical devices that have been reported to trigger serious systemic
reactions by cutaneous exposure include anesthetic masks, tourniquets,
electrocardiogram electrodes, adhesive tapes, condom catheters, and
ileostomy bags.

        Most severe reactions to latex have resulted from latex proteins
contacting mucous membranes of the mouth, vagina, urethra, or
rectum. Materials used in dentistry, including gloves, mouth bite plates,
and orthodontic elastics, are potential allergic sources.

        If you are aware of itching or other allergic reaction to latex
please notify for medical care provider.  Please note this reaction in your medical
records and carry this information in your wallet.  Such reactions are
as important to cite as those of an allergic reaction to penicillin.