Type IV allergy
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Causal agents
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| ■ The main agents responsible for allergic contact eczema (type IV or delayed allergy) in protective glove wearing are: |
- vulcanization accelerators added during rubber processing
(mainly thiurams, carbamates and tetramethylthiuram monosulfide)
- antioxidants
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| ■ The latex itself rarely gives rise to this type of allergy. The prevalence of type IV hypersensitivity to latex (positive patch test) was |
- 2.4% in 167 patients presenting with eczema of the hands ( Gottlober, 2001 ).
- < 1% in a consecutive series of 2738 patients ( Sommer, 2002 ).
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■ In most cases, polysensitization to different chemicals is present. The prevalence of this type of allergy seems to have increased in caregivers since the 1980s ( Gibbon, 2001 ) with a mean of 12% and a peak of 27% in 1994.
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| ■ The coexistence of type I sensitization and type IV sensitization is not frequent. |
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| The lesions affect the backs of the hands and the interdigital spaces. |
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| Four clinical forms are observed ( see table ), ranging from the acute form after an initial contact with the allergen to the chronic form related to persistence of contact with the antigen. The skin thickens and fissures form. |
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| It is sometimes difficult to distinguish the lesions from a latex allergy. Only allergological tests enable differential diagnosis ( patch tests ). A battery of standard allergens is used. The allergens consist in the most widely used vulcanization accelerators in gloves. A sample of the suspect glove is also used (inside and outside surfaces). |
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