kontaktiallergia
Kontaktiallergia, or contact allergy, is a type IV hypersensitivity reaction of the skin triggered by exposure to specific allergens. Sensitization occurs after the first contact, and on subsequent exposure the immune system mounts a T-cell–mediated inflammatory response at the site of contact. The reaction typically develops 24 to 72 hours after exposure and may last for days. It is distinct from irritant contact dermatitis, which does not involve an adaptive immune response.
Pathophysiology involves antigen-presenting cells processing small molecules (haptens) that bind skin proteins. These complexes are presented
Common allergens include nickel (often in jewelry and belt buckles), fragrances, fragrances in cosmetics, latex, rubber
Clinical presentation is typically localized to the contact area and includes redness, itching, swelling, vesicles, and
Diagnosis relies on patch testing to identify relevant allergens. The test is read at multiple time points,
Management centers on avoidance of identified allergens, use of barrier protections (such as non-nickel and fragrance-free