Reaction, allergic complex-forming

A Type III allergic reaction occurs when antibodies of the immunoglobulin G class (IgG) form immune complexes which are slowly eliminated and thus may elicit an inflammatory reaction by binding to the Fey receptors of leukocytes resulting in their activation. 

Cell therapy consists of the parenteral or enteral administration of cells or parts of cell obtained from animal organs and/or tissues from cattle, sheep, pigs, or rabbits. Two different types of cell preparations are in use fresh cells, which are administered in fresh form, and dried cells or so-called sicca cells, which are prepared for later use. The most prevailing risks of cell therapy are local and generalized allergic reactions (fever, nausea, vomiting, urticaria, and anaphylactic shock). Other untoward consequences include fatal and non-fatal encephalomyelitis, polyneuritis, Landry-Guillain-Barre sjmdrome, fatal serum sickness, perivenous leukoencephalitis, and immune-complex vasculitis. 

Skin sensitization tests assess the ability of chemicals to affect the immune system, such that a second contact causes a more severe reaction than the first. The antigen involved is presumed to be formed in the bonding of the chemical to body proteins. The antibodies that form to this ligand-protein complex give rise to an allergic reaction with subsequent exposure. 

Histamine, an amine produced in numerous tissues throughout the body, has complex physiological effects. It is a mediator of allergic and inflammatory reactions, a stimulator of gastric acid production, and a neurotransmitter in several areas of the brain. Histamine is formed by the decarboxylation of L-hisddine in a reaction catalyzed by histidine decarboxylase, a pyridoxal phosphate-requiring enzyme. 

Tincture of iodine was developed as an antiseptic early in the nineteenth century and was employed to treat wounds during the Civil War. However, this form of iodine was found to be quite unstable and overly reactive. Early problems with elemental iodine, including stinging and irritation, allergic/anaphylactic reactions, low solubility, volatility, and poor absorption into tissue, were subsequently improved by complexing iodine with solubilizing agents. 

The patho-mechanism of these papular and urticarial eruptions is unknown. An immune complex reaction may be the basis of the clinical manifestation here. Goh postulated that the allergen is absorbed percutaneously and evoked an allergic contact dermatitis at the primary site, while concurrently forming immune complexes with a circulating antibody (Goh 1989). The immune complexes were probably deposited in the microvasculature and triggered by an inflammatory process that led to the UPPE. Occupational allergens reported to cause UPPE include woods and/or plants, and chemicals. 

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