Allergy Testing (Specific IgE, RAST, CRDT)

Pathology category

Immunology

Code

Various test specific

Referral code

HER

Request form

Test information

Allergen specific IgE: A wide range of allergens are available to test for allergen specific IgE and it is essential that as much clinical information as possible is supplied by the clinician so the most appropriate testing can be performed.

Allergen specific IgE testing is not to be used as a screening test for allergy.

Raised allergen specific IgE (> 0.35KuA/L) can be found without any clinical history of allergic reactions, particularly in atopic individuals. Positive or raised specific IgE is not a 100% proof of allergy and must be interpreted in the light of individual atopic status and clinical history. It is recommended that patients with strong clinical history should to be referred to the Allergy clinic for further evaluation irrespective of total and/or specific IgE levels.

Guidelines

https://www.rcpath.org/static/a49f66cc-3c78-4ee7-97814c34a9d7d462/G194-BPR-Use-of-laboratory-allergy-testing-in-primary-care.pdf

Pre-analytical

See WVT Immunology handbook: Immunology – Worcestershire Acute Hospitals NHS Trust

Reference range

Tube type

Tube type info

SST or Plain

Special requirements

Serum

Minimum volume

See WVT Immunology handbook: Immunology – Worcestershire Acute Hospitals NHS Trust

Assay frequency

See WVT Immunology handbook for specific IgE tests run in house. Other specific IgEs are sent to a further Immunology referral laboratory and results may take 6-8 weeks to come back

TAT Inpatient (urgent)

TAT Inpatient

TAT GP/Outpatient

Variable, depending on tests requested

Referral lab

Immunology, Wye Valley Trust