Pseudo-allergies

The mechanisms of the allergy-like reactions to RCM are still a matter of speculation (table 2). Anaphylaxis to RCM has been discussed to be due to a direct membrane effect possibly related to the osmolality of the RCM solution or the chemical structure of the RCM molecule (pseudo-allergy) [2], an activation of the complement system [27], a direct bradykinin formation [28], or an IgE-mediated mechanism [3]. 

Hypersensitivity, probably as a manifestation of pseudo-allergy is not infrequent. Especially in patients with impaired renal function various skin eruptions can be followed by a potentially fatal syndrome with fever, hepatic and renal dysfunction and eosinophilia. 

Hypersensitivity is defined as a condition in which a defined stimulus causes objectively reproducible symptoms at a dose that is tolerated by normal (most) subjects (Johansson, 2001). Accordingly, hypersensitivity includes both allergic and non-allergic hypersensitivity and hence both immune and non-immune mechanisms. Here hypersensitivity is used in the context of adverse hyper-reactive immunological condition (both true and pseudo allergy) that may result in a clinical condition upon administration of a therapeutic drug. 

Mechanisms of pseudo-allergy or anaphylactoid reactions do not involve adaptive immunity, but rather innate effector components such as complement... 

Moneret-Vautrin, D. A., 1979, Food pseudo-allergy, in The Mast Cell (J. Pepys and A. M. Edwards, eds.), pp. 431-437, Pitman Medical, London. 

The majority of immediate-type adverse reactions to LA seem to be non-immune in nature, earlier called pseudo-allergic [24]. Following the new nomenclature of the World Allergy Organization, these reactions should now be called non-immune anaphylaxis [25]. 

Ring J Pseudo-allergic drug reactions in Korenblat PE, Wedner HJ (eds) Allergy Theory and Practice. Philadelphia, Saunders. 1992, pp 243-264. 

IgE and/or specifically reactive lymphocytes do not mediate many of the adverse reactions to cromoglicate, which mimic allergic processes of the immediate or delayed type. These reactions fulfilled the criteria that characterize pseudo-allergic reactions (3,10). There is a much higher incidence of such adverse reactions when cromoglicate is used orally in the treatment of food allergy, as high as 29% of cases treated (3,10). 

When injected into the skin, local anesthetics often cause pseudo-allergic reactions, with similar symptoms to immediate type allergy (42). However, true immediate hypersensitivity to local anesthetics is extremely rare. 

Tarlo, S.M., Dolovioh, J. Listgarten, C. (1995) Anaphylaxis to carrageenan a pseudo-latex allergy. J. Allergy Clin. Immunol. 95, 933-936. 

Dewdney J (1980) Pseudo-allergic reactions to antibiotics. In Dukor P et al. (eds) PAR Pseudo-allergic reactions, vol 1. Karger, Basel, p 273 De Week AL (1964) Penicillin allergy, its detection by an improved hemagglutination technique. Nature 202 975... 

Dogliotti M (1975) Tests for penicillin allergy. Med Lett Drugs Ther 17 54 Dry J, Leynadier F, Damecour C, Pradalier A, Herman D (1976) Reaction pseudo-anaphy-lactique a la procaine-penicilline G. Nouv Presse Med 5 1401 Dudley KH, Butler TC, Johnson D (1971) Chemical studies of potential relevance to penicillin hypersensitivity the fate of benzylpenicillenic acid in aqueous buffer solutions. J Pharmacol Exp Ther 179 505... 

Psychogenic food intolerance can be due to simple distaste or to overt phobia. We have applied the term pseudo-food allergy to a clinical syndrome in which patients with common psychiatric disorders come to attribute their problems to food allergy in the absence of any objective evidence of organic intolerance. Patients have also been described who have deliberately simulated allergic manifestations in themselves or their children Munchausen s syndrome and Munchausen s syndrome by proxy (Hendrix et al, 1981). 

In adult populations, non-immunologic adverse reactions to foods are almost certainly many times more common than true food allergy. Those which mimic the effects of reaginic sensitivity have been variously described as false food allergies, pseudo-allergic or anaphylactoid reactions. Their true frequency in the general population is not well estab-... 

Warner, J. O., 1983, The problem of diet in food intolerance and pseudo-intolerance. Presented at the British Society for Immunology Food Allergy Workshop. 

Several different intolerance reactions like urticaria, asthmatic attacks and induction of allergies and pseudo-allergic reaction in humans are known (Tsevat, 1987 Acosta, 1989 Simon, 1993). Sulfites irritate the skin and mucous membranes (Wuthrich, 1993). 

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