- What is a metal allergy?
- Which symptoms may indicate a metal allergy?
- Which metals can induce an allergy?
- In which everyday items or medical products can sensitizing metals be found?
- Do certain occupations pose a special risk for inducing metal allergy?
- In which fields of medicine does a metal allergy play an important role?
What is a metal allergy?
Many everyday metals can cause a Type IV allergic reaction in genetically predisposed individuals. This allergy is mediated by T-lymphocytes (white blood cells) that have had prior contact with a given allergen (memory lymphocytes). When they are exposed to the sensitizing allergen, these memory lymphocytes respond by enlarging (lymphoblast transformation) and dividing (proliferation). The newly formed cells (effector cells), together with their secreted cytokines, mediate the resulting allergic reaction. See How does the MELISA test work?
Which symptoms may indicate a metal allergy?
The classic symptom of metal allergy is contact dermatitis (eczema). In addition to local symptoms, chronic exposure to metals may cause a wide range of systemic symptoms. Metal allergy has been implicated in the etiology of chronic fatigue syndrome (CFS), multiple sclerosis (MS), fibromyalgia and multiple chemical sensitivity (MCS).
Do certain occupations pose a special risk for inducing a metal allergy?
(Note: this list is not exhaustive).
Construction industry (mason, concrete worker): chromium, cobalt.
Mining: chromium, cobalt.
Electrician, photographer: chromium.
Aircraft construction: beryllium.
Hairdresser, beautician: nickel, titanium.
Galvanizer: nickel, chromium, cobalt, mercury.
Rubber industry: chromium, cobalt.
Wood and paper industry: chromium.
Painter: chromium, cobalt.
Metal worker: chromium, nickel, cobalt.
Textile industry, dentist, dental technician: nickel, mercury.
How can a metal allergy be diagnosed?
With a skin test or, more objectively and safely, with the MELISA test.
How does the MELISA test work?
MELISA is an acronym for Memory Lymphocyte Immunostimulation Assay. White blood cells (lymphocytes) from whole blood are isolated and tested against allergens chosen according to the patient’s anamnesis, including dental and occupational history. The blood is incubated for five days and the lymphocyte reaction is measured by two separate technologies: one based on the uptake of a radioisotope by dividing lymphocytes; the other on an evaluation by microscopy. The level of reactivity is measured as a Stimulation Index (SI). A value over 3 indicates a positive reaction to a given allergen. Finally, a report is produced.
What material is required for the MELISA test?
A MELISA laboratory needs 20-40 ml of blood depending on the number of metals to be tested. The blood has to be drawn into special tubes containing sodium citrate (an anti-coagulant). The patient should not be taking any immuno-suppressive medication as this may affect the test results. Examples of such medication are steroids, allergy medicine, anti-inflammatory medicine, painkillers etc.
Can the blood samples be sent to a laboratory?
Yes, with a courier such as FedEx or DHL. The blood sample must be kept at room temperature and arrive in the laboratory ideally within 24 hours (maximally 48 hours) of drawing. Write on package: “Warm transport, do not chill”. Label samples “Diagnostic specimens, non-infectious, non-hazardous”. See Order MELISA and Sending blood for more details.
How long does the MELISA test take?
Results are normally available approximately 10 days after receipt of sample.