49. Latex Allergy Flashcards

1
Q

A staff nurse presents for elective surgery and claims to have a history of
possible latex allergy.
Who is at risk from developing latex allergy?

A

Patients with previous documented reactions

Those exposed to repeated medical or surgical procedures involving the use
of latex (especially bladder catheterisation)

Health-care workers

Patients with a history of atopy (may show cross-reactivity with certain
foods especially banana, chestnuts and avocado)

In spina bifida patients the prevalence may be as high as 60%.

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2
Q

What types of allergy to latex do you know?

A
  1. Contact dermatitis
    Type IV delayed hypersensitivity reaction to the
    chemical accelerators, anti-oxidants and stabilisers
    used in the manufacturing process
    T-cell mediated
  2. Anaphylaxis
    Type I immediate hypersensitivity reaction to latex
    proteins in previously sensitised patients
    IgE mediated
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3
Q

How do you test for it?

A

Testing takes place 4–6 weeks after the reaction.

  1. Skin-prick testing

Involves puncturing the skin with a thin needle
through a drop of dilute antigen. The
concentration of solution is important to avoid
false negatives. There is a smaller risk of
anaphylaxis than with intra-dermal testing.

  1. RAST Radioallergoabsorbent testing is less sensitive and
    more expensive than skin-prick testing, but avoids
    the risk of anaphylaxis.

As there are many different latex proteins that may be implicated in the
allergic response, a negative response to one antigen does not imply that the
patient is not latex sensitive. A strong clinical history suggestive of allergy is
important

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4
Q

How would you manage this case?

A

Having already been notified in advance,
there is time to prepare the theatre
environment and equipment necessary to undertake such a case.

All theatre and ward staff should be aware of the necessary precautions to be taken.

There should be a ‘latex-free’ box of equipment available and lists of
equipment that are:.

  1. Latex-free
  2. May be modified to be used.
  3. Must not be used at all.

The patient should be first on the list and anaesthetised in a
theatre unoccupied for at least 2 hours. The most important piece of
equipment is latex-free gloves. All other equipment should be checked with
the database in the ‘latex-free’ box.

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5
Q

Pre-medication is controversial,

A

Pre-medication is controversial, but may be given to patients who are
considered to be very sensitive.
A suggested protocol for adults IV chlorpheniramine 10mg 6 hourly
would be IV ranitidine 50mg 8 hourly
IV hydrocortisone 100mg 6 hourly
Salbutamol (inh/neb) for asthmatics

This would be given for 24 hours pre-operatively and at least 12 hours
post-operatively.

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6
Q

Latex anaphylaxis:

A

Reaction typically begins 30–60 minutes after the start of the
procedure (cf. anaphylactic reaction to i.v. drugs).

Management as for anaphylaxis –
think of latex-free environment as soon as is practical

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