Immediate skin reactions

Numerous positive delayed skin tests in patients with contrast medium-induced non-immediate skin reactions have been reported when the patients were tested with the culprit contrast medium [summarized in 1]. In a large European multicenter study, 37% of patients with non-immediate reactions were positive in delayed IDEs and/or patch tests [13]. The majority of the patients also reacted to the culprit contrast medium and also to other, structurally similar RCM. Notably, in more than 30% of those skin test-positive patients a RCM had been administered for the first time. Thus, there is a lack of a sensitization phase. Again it may be hypothesized that these previously non-exposed patients may have already been sensitized. Different patterns of RCM cross-reactivity indicate that several chemical entities could be involved. No positive skin tests have been obtained with other contrast medium excipients, such as ethylenediaminetetraacetic acid (EDTA), and only rarely patients have been found to react to inorganic iodide. 

To investigate the role of these cytokines in immediate skin reactions in humans, single nucleotide polymorphism (SNP) studies were conducted within small subsets of patients known to have allergies to p-lactams (Guglielmi et al. 2006a Qiao et al. 2007 Yang et al. 2005). SNPs within the IL-4, IL-13, IFN-y, and their respective... 

The important role of aggregates as elicitors of skin reactions to HSA (Ring 1978 a) is evident from results obtained in patients challenged intradermally with the following HSA preparations monomeric HSA (2 in 12), albumin aggregates (9 in 12), and commercial HSA solution (5 in 12). The figures in parentheses indicate the frequency of positive immediate skin reactions. 

Upon intradermal injection of 0.05 ml undiluted clinical HES solution, positive immediate skin reactions were observed in five of eight reactors to HES, tested between 10 days and 2 months after the reaction (Ring et al. 1976). Three of these patients, who exhibited grade II-III reactions also showed positive skin tests with a 1 10 dilution and two with a 1 100 dilution of clinical HES solution. These results indicate that skin tests may be of a certain diagnostic value for severe HES reactions. 

Niinimaki A, Hannuksela M (1983) Immediate skin reactions 489, to spices. Allergy 51 269-272... 

An allergic reaction towards MC insulin has been reported (5 ) in a patient who earlier had shown allergic reactions towards NPH insulin. After 3 weeks of therapy with MC insulin immediate skin reactions developed late reactions were also seen. Direct skin tests and passive cutaneous reactions were negative. Other authors report a positive effect of MC insulin on lipodystrophy (in 6 patients) (d -) and on other allergic reactions (see 7 —9, 10 ), but antibodies could still be demonstrated in the patients concerned, despite the improvement which they exhibited. 

The most common clinical picture of non-immediate RCM reactions is a macu-lopapular exanthema, which resembles other drug-induced T-cell-mediated hypersensitivity reactions. The reported onset of skin eruptions 2-10 days after the first exposure to a RCM and 1-2 days after re-exposure to the same substance is typical for an allergic drug reaction with a sensitization phase. 

Toxicology. NRL causes allergic skin reactions of type I (immediate-type) and type IV [delayed-type hypersensitivity (DTH)]. 

They are mediated by IgE antibodies. On exposure to the drug, antigen and antibody reaction takes place on mast cells and basophils releasing various mediators e.g. histamine, leukotrienes, 5 hydroxytryptamine (5-HT), prostaglandins etc., which are responsible for immediate immune reactions like skin reaction, anaphylactic shock, asthma etc. These reactions occur immediately after challenge and are termed as immediate hypersensitivity. 

The activation of mast cells and T cells results in late-phase reactions. Both immediate hypersensitivity and late-phase reactions are evident in the skin of atopic as well as nonatopic individuals after the cross-linking of IgE-bound mast cells with an antibody against IgE. The atopic asthmatic could develop late-phase reaction even in the absence of mast cell-related immediate hypersensitivity reaction, which is mast cell-independent and HLA-dependent, suggesting the role of T cells by themselves in causing asthma symptoms in atopic asthmatics. 

Solley GO, Gleich GJ, Jordon RE, Schroeter AL. 1976. The late phase of the immediate wheal and flare skin reaction. Its dependence upon IgE antibodies. J Clin Inv. 58 408 120. 

It is a potentially lethal immediate hypersensitivity reaction, in whose pathomech-anism the main role is played by IgE antibodies. Mediators released in the process are responsible for tissue reactions, which may involve the respiratory system, gastrointestinal system, and the skin or cardiovascular system. 

Niinimaki, A. and Hannuksela, M. 1981. Immediate skin test reactions to spices. Allergy 36 487 193. 

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