09/06/2008

Guidelines on latex allergy

The British Occupational Health Clinical Effectiveness Unit (OHCEU) is
currently working on two new guidelines for the Management of Dermatitis within
the workplace and the management of Upper Limb Disorders in the workplace.

Latex allergy imposes a public health burden with costs to the individual and
the employer, as well as to the economy.

Impact on the allergic employee

Impact may be considered in terms of both physical and economic impairment.
Individuals may experience discomfort, inconvenience and even life-threatening
symptoms from latex allergy. There may be impact on their personal lives, eg
inability to blow up balloons, or potentially life-threatening symptoms on
ingesting food that has been handled with powdered NRL gloves. They may also
have periods of sickness absence or be unable to continue working in the same
role, resulting in loss or reduction of their income.

Types of rubber allergy and causes

Clinical effects of rubber allergy are attributable to either type I
(immediate-type) hypersensitivity or type IV (delayed-type) hypersensitivity.

Type I, or immediate-type hypersensitivity

Type I, or immediate-type hypersensitivity, is manifest by IgE (immunoglobulin
E)-associated reactions to latex proteins, precipitated in individuals who have
already developed latex-specific IgE antibodies from previous exposure and
sensitisation. At least 13 proteins have been identified by the International
Union of Immunological Societies (IUIS) as latex-specific allergens capable of
causing type I allergy. Clinical manifestations may be cutaneous, ocular,
respiratory or systemic. They range from contact urticaria, itching of the skin
and eyes, sneezing, bronchospasm and asthma, to anaphylaxis (which may occur in
people previously unknown to be sensitised). Cornstarch powder (absorbable
dusting powder) on powdered latex gloves, originally introduced to facilitate
donning, increases the risk of sensitisation as the latex proteins are carried and made airborne by the powder particles. The
absorbable dusting powder in itself has not been shown to cause type I allergy.

Type IV, or delayed-type hypersensitivity

Type IV hypersensitivity reactions are more common and usually represent
cell-mediatedreactions to the chemical additives in rubber rather than the latex proteins.
Strictly speaking, these should therefore be considered as a rubber allergy
rather than a latex allergy. The clinical presentation is a vesicular,
eczematous, pruritic dermatitis appearing hours to days after contact with the
allergen. Large-scale patch-testing studies have been undertaken using
individual rubber additives, and established allergens include rubber
accelerators of vulcanisation (mercaptobenzothiazoles, carbamates and
especially thiurams),22 antioxidants (eg amines), and organic pigments. In
latex gloves, the most common type IV allergens are the thiurams, and screening
panels for these are found in the most basic patch-test trays. Since 1992, some
cases have also been reported of type IV allergy to latex proteins, without the
presence of rubber chemicals, ie protein contact dermatitis, with or without
concomitant type I allergy. However, these are rare.

Different summary leaflets for employers, employees and healthcare
professionals are available.


More info


AplusA-online.de - Source: Occupational Health Clinical Effectiveness Unit