Environmental allergy reactions

Chronic pain syndromes (multiple etiologies) Environmental allergy reactions (Universal)... 

In addition to the proteins discussed above, a large number of reactive chemicals used in industry can cause asthma and rhinitis. Hypersensitivity pneumonias have also been described. Isocyanates and acid anhydrides are industrial chemicals that cause occupational asthma. Acid anhydrides, such as phthalic anhydride, seem to cause mainly type I reactions, whereas the IgE-mediated mechanism explains only a part of the sensitizations to isocyanates. Several mechanisms have been suggested, but despite intensive research no models have been generally accepted. The situation is even more obscure for other sensitizing chemicals therefore, the term specific chemical hypersensitivity is often used for chemical allergies. This term should not be confused with multiple chemical sensitivity (MCS) syndrome, which is a controversial term referring to hypersusceptibility to very low levels of environmental chemicals. ... 

Immunoenhancement, which, as adverse effect, may lead to immune-mediated diseases such as hypersensitivity reactions and autoimmune diseases. Hypersensitivity reactions are the result of normally beneficial immune responses acting inappropriately, causing inflammatory reactions and tissue damage. The two most frequent manifestation of chemical-induced allergy are contact hypersensitivity and respiratory sensitization, both of which can have a serious impact on quality of life and represent a common occupational health problem. Hypersensitivity reactions are often considered to be increased at such a rate to become a major health problem in relation to environmental chemical exposure. 

It is unclear why certain foreign proteins can also stimulate the B-cells to secrete IgE antibodies, to result in allergy or hypersensitivity. The terms are used interchangeably, although the latter is usually restricted to milder forms of the response. The term anaphylaxis is used to describe the severe response (Box 17.4). Both reactions arise in genetically susceptible individuals and they are precipitated by exposure to environmental antigens such as pollen, some organic compounds, tobacco smoke, animal hairs or even components of some common foods such as milk and cereals. 

There is evidence that both occupational and environmental exposures to chemicals (both proteins and haptens) can result in the induction or exacerbation of respiratory allergies (Table 19.6). Of particular concern is the induction of allergic asthma. In sensitized asthmatic individuals the antigen challenge generally causes a type I (IgE-mediated) immediate hypersensitivity response with release of mediators responsible for bronchoconstriction. Between 2 and 8 hours after the immediate response, asthmatics experience a more severe and prolonged (late phase) reaction that is characterized by mucus hypersecretion, bronchoconstriction, airway hyperresponsiveness to a variety of nonspecific stimuli (e.g., histamine, methacholine), and airway inflammation characterized by eosinophils. This later response is not mediated by IgE. 

Conjunctivitis is an inflammatory process of the conjunctiva that varies in severity from ntild hyperemia to severe purulent discharge. Common causes of conjunctivitis include viruses, allergies, environmental irritants, contact lenses, and chemicals. Less common causes include other infectious pathogens, immune-mediated reactions, associated systemic diseases, and tumors of the conjunctiva... 

Calnan CD, Caron GA (1961) Quinine sensitivity. Br Med J 2 1750-1751 Calnan CD (1976) Quinazoline yellow SS in cosmetics. Contact Dermatitis 2 160-166 Campbell AD, Horwitz W, Burke JA, Jelinek, CF, Rodricks JV, Shibko SJ (1977) Food additives and contaminants. In Hall VF (ed) Handbooks of physiology, sect. 9. Reactions to environmental agents, Wilhams Wilkins, Baltimore, pp 167-179 Castelain PY (1977) L allergie aux colorants alimentaires. Med Nutr 13 112-113 Chafee FH, Settipane GA (1967) Asthma caused by FD C approved dyes. J Allergy 40 65-72... 

It is important to recognize that delayed chemical allergy can occur even some time afto" the chemical has been removed. Contact with poison ivy is a familiar example of an exposure that causes a delayed allergic reaction. Also, just as people vary widely in their susceptibility to sensitization by environmental allergens such as dust and poUen, individuals may also exhibit wide differences in their sensitivity to laboratory chemicals. Examples of substances that may cause allergic reactions in some individuals include diazomethane, dicyclohexylcarbodiimide, formaldehyde, various isocyanates, benzyUc and aUyUc halides, and certain phenol derivatives. 

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