Allergy to rubber latex is an international health problem now. People
who are at the highest risk of getting this disease are those working
in the health care industry, rubber industry and those who have undergone
multiple surgeries.
Types of allergies
There are three types of reactions to rubber latex; irritant contact
dermatitis, allergic contact dermatitis (Type IV allergy) and immediate-type
hypersensitivity reactions (Type I allergy).
Irritant contact dermatitis: Irritant contact dermatitis is non-immune
eczematous reaction caused by moisture, heat and friction under the
latex gloves. Severity of the reaction depends on the length of exposure,
state
of the skin barrier system and skin temperature. There is itching, scaling
and erythema followed by thickening of the skin. The use of a cotton
liner under NRL gloves can help.
Allergic contact dermatitis (Type IV allergy): This is a delayed-type
hypersensitivity reaction and comprises 80% of all occupation related
contact dermatitis. Out of 100 cases of chronic hand dermatitis in
surgical personnel and dentists, 11 were found to be allergic to rubber
latex
hand gloves.
Allergic contact dermatitis is an immune system mediated sensitization
to rubber accelerators, such as, thiurams and carbamates and to
antioxidants in latex gloves. The reaction is usually confined to
the area of direct
contact. Glove allergy was caused by thiurams in 72% cases, carbamates
in 25% cases and mercapto compounds in 3% cases. Repeated exposure
to the same allergen, which caused the sensitization, generally
worsens the condition. It can produce an eczematous reaction featuring
erythema,
scaling
and vesiculation that may lead to the life threatening ‘Type 1’ allergy.
Having both "Type IV" and "Type I" natural rubber
latex allergy is both possible and worse than either type of allergy alone.
Diagnosis
The diagnosis is made by patch testing. The standard patch test
screening series contains the chemicals found in rubber latex
glove products.
Patch testing with a thin piece of a rubber latex product may
be helpful, but
not in ‘Type 1’ allergy cases.
Hand dermatitis and atopic diseases are increased risk factors
for rubber latex allergy.
Treatment
Once patch testing has identified the offending allergen,
rubber products that do not contain those allergens, or
do not contain
chemicals which
produce them, should be obtained. Patients who have undergone
or will need to undergo multiple surgical procedures should
be offered
a latex-safe
hospital environment.
Surgeons with rubber sensitivity may use Elastyren hypoallergenic
surgical gloves. Unlike latex rubber, Elastyren is not
vulcanized and therefore
contains no metal oxides, sulfur, accelerators, or mercaptobenzothiazole,
sensitizers commonly found in rubber products. Allerderm
vinyl gloves, for household use, can be used with a
cotton liner.
Hypoallergenic vinyl gloves for examination are generally
available.
Immediate-type hypersensitivity reactions (Type I allergy)
‘Type I allergy’ is also an immune system mediated reaction. Its
development requires previous sensitization. Subsequent exposure to the
offending allergen induces the release of histamine and other mediators.
Exposure of the skin to latex produces contact uritcaria
and exposure to latex in the air causes allergic
rhinitis, conjunctivitis,
asthma, anaphylaxis, and even death. Patients,
with allergy to
rubber latex,
are vulnerable in a hospital setting. Latex allergy
can present itself as
anaphylaxis during surgery, barium enema, or dental
work. Intraoperative anaphylaxis and death can
occur due to
mucosal latex absorption
at the time of surgery or procedure, because of
exposure to the surgeon’s
latex gloves.
Mucosal exposure can occur from airborne powder
particles, used as dry lubricant in gloves.
The powder acts as
a vehicle for
carrying the latex
proteins in the air. These particles are dispersed
when the gloves are removed and cause aerosol
contamination, resulting
in asthma.
Patients with Type I rubber latex allergy can
have a cross-reaction to certain foods. Anaphylactic
reactions to banana, avocado,
or tomato, or
local irritation when working with such foods
have
been
reported.
Diagnosis
A RAST screening test to detect latex-specific
IgE can be done on patients with a history
of reactions
from
rubber exposure. If the
RAST test is
positive, no further tests are needed. If
negative, a ‘use test’ using
a latex glove in a supervised setting may be performed, first with one
finger, then with the hand. If still negative, a skin-prick test should
be done with eluted latex protein in solution. Anaphylactic reactions
can happen with the ‘use’ and the skin-prick tests, so life
saving equipment must be available.
Treatment
Health care workers, with type I reactions,
should wear non-latex gloves, while
low-allergen, powder-free
gloves
should be worn
by other health
care workers at that worksite Instead
of single vinyl gloves, double-gloved vinyl gloves may provide greater
protection
during the
mucosal examinations.
Thermoplastic elastomer gloves are expensive
but provide a protection
as good
as rubber latex
gloves.
