Allergic skin manifestations

Allergic skin manifestations include: urticaria caused by immunological mechanisms and angioedema, allergic contact dermatitis and atopic dermatitis.

Urticaria induced by immunological mechanisms

 * Anaphylactic type of hypersensitivity (IgE-mediated allergy; type I) - short-term acute reaction to food, medication or contact allergens.
 * Immunocomplex type of hypersensitivity (non-IgE mediated allergy; type III) - serum disease type reaction after treatment with penicillin or after application of foreign organ extracts containing proteins (foreign sera, hormones) and urticarial vasculitis.
 * Autoimmune mechanisms (type II; autoantibodies, especially IgG1 and IgG3 classes against the FcεRIα receptor of mast cells, or against IgE immunoglobulins) - chronic urticaria, sometimes in association with autoimmune thyroid disease, dermatomyositis or SLE.

Angioedema

 * Deficiency in the complement system (inhibitor of the C1 component of complement) - angioedema (hereditary, acquired and arising as an adverse effect of drugs from the group of ACE inhibitors).

Allergic contact dermatitis

 * itchy eczematous deposits at the points of contact with the allergen (nickel and other metals, topical drugs, perfumes, preservatives and rubber - thyomersal)
 * delayed type hypersensitivity reaction (type IV), mediated by hapten-specific T cells
 * diagnostics - epicutaneous tests.

Atopic eczema

 * chronic, recurrent, itchy skin disease.

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 * Allergy