Contactsczemas and Patch testing
Contact eczemas are skin disorders, which
develop through contact with externally added substances. They may have an
allergic cause (e.g. nickel eczema). However, they can also result from simple
irritation of the skin (e.g. abrasion eczema due to frequent contact with
cleaning agents). Allergic contact dermatitis may also be caused by cosmetics,
jewelry, leather, preservatives, cream or ointment bases, or by textiles.
Contact eczema is manifested through pruritus, redness, blistering, or flaking at the site of contact, but allergic contact eczema can also spread to other areas of the body.
- Nickel allergy (nickel eczema)
- Abrasions due to frequent contact with cleaning agents (abrasion eczema)
- Allergic contact eczema may result from exposure to specific constituents in cosmetics, jewelry, preservatives, ointment bases, or even textiles.
The most important measure in allergy diagnosis is skin sensitivity or epicutaneous testing (patch test). In this test, adhesive patches containing allergens are applied to the patient’s back and left in place for two days. On day three, the patches are removed, and reactions are evaluated on the third and fourth day.