Different Patterns of Response in Hypersensitivity Reactions to Arylpropionic Acid Derivatives

BACKGROUND

Ibuprofen and other arylpropionic acid derivatives (APs) are among the most consumed nonsteroidal anti-inflammatory drugs worldwide at all age ranges; however, little is known about drug hypersensitivity reactions (DHRs) they induce.

OBJECTIVE

To characterize in detail patients reporting DHRs to APs.

METHODS

We prospectively evaluated patients with symptoms suggestive of AP-DHRs and analyzed their clinical characteristics, reported reactions, and diagnostic approaches.

RESULTS

Six hundred sixty-two patients confirmed as hypersensitive to APs were included: 489 with cross-reactive reactions (CRs) (73.86%) and 173 with selective reactions (SRs) (26.13%). The percentage of subjects reporting reactions to ibuprofen and dexketoprofen was higher in CRs (P = .005 and P = .01, respectively), whereas naproxen and ketoprofen were more frequently involved in SRs (P = .0002 and P = .00001, respectively). The most frequent symptoms induced by ibuprofen, dexketoprofen, and naproxen were isolated angioedema and urticaria, combined or not with angioedema in both CRs and SRs. The result of nasal provocation test with lysine acetylsalicylate was positive in 156 cases (77.14% in patients showing exclusively respiratory symptoms, and in 68.18% of those with both cutaneous and respiratory involvement). To confirm diagnosis, drug provocation test with acetylsalicylic acid was required in 246 CR patients (50.3%), whereas in 28 SR patients (16.18%) drug provocation test with the culprit AP was required.

CONCLUSIONS

Skin is the organ most commonly involved in AP-DHRs, with ibuprofen and dexketoprofen inducing most frequently CRs, and naproxen and ketoprofen SRs. More studies are necessary to clarify the underlying mechanism in DHRs induced by APs.

Comparison of the efficacy and safety of two preseasonal regimens of glutaraldehyde modified, tyrosine-adsorbed parietaria pollen extract over a period of three years in monosensitive patients

The purpose of this study was to evaluate the clinical efficacy over a period of three years (1988-90) of two preseasonal dosage regimens of a Parietaria allergoid (Bencard Tyrosine Parietaria) in patients who were only sensitive to this pollen. Fifty patients were included (14 men and 36 women, age: mean, 28 years; range, 14-47 years). Twenty five patients (group A) were treated each january with the basic course of Bencard Tyrosine Parietaria. This consisted of injecting subcutaneously 0.5 ml from each of three vials, with one week between each injection. A further injection using the vial with the highest dose was given one week later. Each january and february, twenty five patients (group B) were treated with the basic course of Bencard Tyrosine Parietaria, repeating the last dose five times, with one week between each injection. Immunotherapy with a tyrosine-adsorbed Parietaria judaica allergoid is an effective method for mitigating nasal (p < 0.0001), bronchial (p < 0.005), conjunctival (p < 0.001) and palatal itching symptoms (p < 0.0001) in patients who are sensitive to this pollen. Sensitivity to Parietaria pollen, as verified by skin test and nasal challenge, decreased during immunotherapy (p < 0.001). Histamine release by peripheral blood basophils decreased during the course of the study, falling from 43.5 ng/ml to 12.3 ng/ml in group A and from 42.9 ng/ml to 10.0 ng/ml in group B; during the second and third years, IgG levels were increased one and four months after starting treatment with the extract, while this was not the case after ten months; IgE levels were also increased. Finally, overall tolerance to this immunotherapy product was good in almost all patients.

Antiallergic properties of antihistamines

Histamine is a major mediator of the allergic reaction, and histamine H1-receptor antagonists have a long history of clinical efficacy in a variety of allergic disorders. The pathogenesis of allergic disease is complex, involving not only histamine and mast cell-derived tryptase, but also eosinophil and neutrophil derived mediators, cytokines, and intercellular adhesion molecules (ICAM-1). A number of "in vitro" and "in vivo" studies have been performed to assess the clinical effectiveness of antihistamines in inhibiting the allergen-induced inflammatory process in the skin and mucosa. In vitro human studies have shown that high concentration of second generation antihistamines can block inflammatory mediator release from basophils and mast cells, and reduce ICAM-1 expression in epithelial cell lines. In vivo studies have also shown an effect on the allergen-induced inflammatory reaction; both oral and intranasal antihistamines cause a reduction in nasal symptoms and inflammatory cell influx. Analysis of secretory fluids and tissues after challenge indicates that antihistamines interfere with mediator release. Recruitment of inflammatory cells to the site of the allergic insult is also disturbed by antihistamines of second-generation, suggesting that these drugs may inhibit upregulation of molecules involved in cell adhesion and migration, and perhaps they may interfere with the cytokine cascade through their ability of stabilizing mast cells and of limiting the incursion of inflammatory cells. This article reviews available human data on the antiallergic effects of antihistamines.