Recurrent anaphylaxis: a case of IgE-mediated allergy to carmine red (E120)

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Nickel free-diet enhances the Helicobacter pylori eradication rate: a pilot study.

BACKGROUND: The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach. AIM: To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen. METHODS: Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet. RESULTS: All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups. CONCLUSIONS: The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.

The clinical meaning of positive latex sIgE in patients with food/pollen adverse reactions.

Natural rubber latex allergy (NRL-A) is an international problem of public health. About 50-60% of NRL-A patients may present adverse reactions after ingestion of cross-reacting vegetable foods. This condition, called "Latex-fruit Syndrome", is a matter of research. The aim of our study is to distinguish between clinical/subclinical latex-fruit syndrome and cross-sensitization to latex and food/pollen allergens on the basis of latex recombinant allergens. We studied 51 patients with food hypersensitivity and serological evidence of NRL sensitization. The subjects underwent an accurate allergological evaluation (skin prick test with latex, food and pollen extracts, specific IgE to latex and recombinant allergens, challenge provocation tests). The patients were divided in two groups: group A) 34 patients with clinical and serological latex and fruit/vegetable allergies; group B) 17 patients allergic to fruits/vegetables and/or pollens, with serological, but not clinical NRL-A. All the latex challenge tests resulted positive in group A patients and only two patients of group B presented positive cutaneous challenge tests. Moreover, specific IgE-antibodies were detected to rHev b 5, to rHev b 6.01, to rHev b 6.02 and to rHev b 8 (and other profilins) of group A patients, while in group B we observed a monosensitization to Hev b8, probably linked to a cross-sensitization to pollens and foods. At the present state of knowledge, we need a multi-parametric approach based on a combination of clinical history, diagnostic tests (CRD) and latex challenge tests to make diagnosis of latex-fruit syndrome.

Skewed T-cell receptor repertoire: more than a marker of malignancy, a tool to dissect the immunopathology of inflammatory diseases.

The highly diverse heterodimeric surface T cell receptor (TCR) gives the T lymphocyte its specificity for MHC-bound peptides needed to initiate antigen-recognition. In normal peripheral blood, spleen and lymph nodes, the TCR repertoire of the T lymphocytes is usually polyclonal. However, in malignancies such as leukemias, as well as in lymphoproliferative diseases of mature T cells, the TCR is a reflection of the clonality of the malignant cells and is therefore monoclonal. Several clinical conditions (mainly solid tumors and autoimmune diseases) have been described where the TCR repertoire is restricted. The ability to demonstrate clonal TCR usage provides a useful tool to dissect the immunopathology of inflammatory diseases. In this review we discuss these findings and propose to sub-divide diseases with restricted TCR repertoire into a group of conditions in which there is a known TCR ligand, as opposed to diseases in which the restricted TCR repertoire is the result of impaired T-cell development. This classification sheds light on the pathogenesis of several inflammatory diseases.

Tolerability of aztreonam in patients with cell-mediated allergy to ß-lactams.

BACKGROUND: Cross-reactivity between aztreonam and ß-lactams is poor, but tolerability of aztreonam has been assessed in a few groups of patients suffering from IgE-mediated allergy to ß-lactams. The aim of this study was to assess the cross-reactivity of aztreonam with other ß-lactams and its tolerability in patients with cell-mediated allergy to these drugs. METHODS: We studied 78 patients with cell-mediated allergy to ß-lactams who underwent skin prick, immediate and delayed-reading intradermal tests as well as patch tests with penicilloyl-polylysine, minor determinant mixture, semi-synthetic penicillins, cephalosporins, aztreonam and imipenem. Patients with negative allergy testing with aztreonam underwent an intramuscular test dosing and were observed for 3 h. RESULTS: Our patients experienced 94 non-immediate reactions; delayed-onset urticaria (34 cases), maculopapular exanthema (13 cases), urticaria/angioedema (15 cases) and itching erythema (13 cases) were the most reported symptoms. Amoxicillin (35 cases), ampicillin (28 cases) and bacampicillin (18 cases) were the most involved drugs. All patients had a positive patch test and/or a positive delayed-reading intradermal test to at least 1 ß-lactam antibiotic and none had a positive patch or delayed-reading intradermal test to aztreonam. Then, 65 patients underwent intramuscular test dosing with aztroenam, and none of them had a clinical reaction. CONCLUSIONS: Our data confirm the lack of cross-reactivity between ß-lactams and aztreonam in patients with cell-mediated allergy to these drugs. Delayed-reading intradermal tests and patch tests with aztreonam represent a simple and rapid diagnostic tool to establish tolerability in ß-lactam-allergic patients.

Allergic and non-allergic drug hypersensitivity reactions in children.

Adverse drug reactions (ADR) are an important medical problem. The aim of this study is to investigate the clinical characteristics of children with ADR and to assess the tolerability of alternative drugs in children (under 16 yrs of age) with a history of ADR. We studied 278 children (132 males and 146 females). Patients were studied by recording personal history and performing in vivo skin testing, in vitro laboratory tests and challenge tests. Patients who had experienced mild adverse reactions underwent challenge tests without any premedication; patients with a clinical history of moderate reactions, received a premedication with sodium chromolyn 30 min before the oral challenge; patients with a clinical history of severe reactions or undergoing parenteral challenges, were given an antihistamine 30 minutes before. A total of 660 adverse events were reported with 126 different drugs involved. Antimicrobial agents were the most involved drugs (51.7%). Non-steroidal anti-inflammatory drugs were involved in 22.7% of episodes. The most reported symptoms were cutaneous. Allergy testing was negative in 272 patients. A diagnosis of drug allergy was reported for 6 patients. A total of 669 challenge tests were performed. 639 were negative at first attempt while 22 were positive. Eight were repeated using a different premedication and resulted negative. Hypersensitivity drug reactions in children are mainly non-allergic. A premedication with sodium cromolyn or with oral H1-antihistamines may be useful in preventing ADR.

Delayed allergy to aminopenicillins: clinical and immunological findings.

Aminopenicillins are the most used beta-lactam antibiotics. Morbilliform or maculopapular rashes are rather frequent during therapy with aminopenicillins. The pathogenesis of these reactions is often due to a cell-mediated allergy. The aim of this work is to characterize patients with cell-mediated allergy to aminopenicillins and to identify alternative beta-lactam drugs that can be safely administered to these patients. We studied 27 subjects affected by cell-mediated allergy to aminopenicillins. The diagnosis was made on the basis of positivity of patch tests with aminopenicillins. These patients then underwent an allergological evaluation (skin and patch tests, oral and/or intramuscular challenge tests) with a wide spectrum of beta-lactam antibiotics. Our work highlights the following main characteristics of cell-mediated allergy to aminopenicillins: time elapsing between drug administration and onset of symptoms of about 2 days; the maculopapular rash and delayed appearance of urticaria/angioedema were the most typical symptoms (82.8 percent of cases); a cross-reactivity with aminocephalosporins is usually absent, or it is limited to cephalexin (in our study, in fact, just 3 out of 20 patients challenged with cephalexin showed a positive oral challenge test); all the beta-lactams, other than aminopenicillins, are well tolerated. Patch tests represent a specific diagnostic tool with a good predictive value of identifying alternative drugs that can be safely administered to patients with beta-lactam allergy. Our patients could tolerate other beta-lactam drugs after a complete allergological evaluation. On the basis of our study, cell-mediated allergy to aminopenicillins should be considered a well-defined nosologic entity.

Sublingual desensitization in children with congenital malformations and latex allergy.

The frequency of latex allergy in children requiring multiple surgery ranges from 16.7% to 65%. The aim of this study was to investigate the safety and efficacy of latex desensitization in a group of 10 patients with a history of multiple surgical procedures and clinically manifested allergy to latex. We selected 10 children (female-male ratio = 5:5), aged 4-16 yr (mean +/- s.d.: 9 +/- 4), with a history of multiple surgical procedures, adverse reactions to latex and positive skin test to latex and/or specific immunoglobulin E (IgE). Latex allergy diagnosis was confirmed by specific provocation tests (cutaneous, sublingual, mucous, conjunctival tests). Rush (4-day) sublingual desensitization was performed with increasing doses of latex extract (ALK Abellò) under patients' tongue until the highest dose of 500 microg of latex. A maintenance therapy (10 drops of undiluted solution three times a week) was recommended. During the 2-yr follow-up mean values of specific IgG4 and IgE, eosinophilic cationic protein and total IgE did not show significant variations. Patients did not manifest any adverse effect during the rush phase and only two patients manifested mild local symptoms during the maintenance therapy. All the challenges showed a reduction in terms of percentage of positivity and mean scores. All the patients showed a reduction of the mean individual score (p < 0.001). Furthermore patients who needed dental examination or surgery underwent such procedures without the occurrence of symptoms. Our preliminary results show sublingual desensitization to latex can be an important therapeutic tool in the management of young allergic patients requiring multiple operations.

A clinical trial of oral hyposensitization in systemic allergy to nickel.

Nickel allergy is the most common contact allergy. Some nickel-sensitive patients present systemic (cutaneous and/or digestive) symptoms related to the ingestion of high nickel-content foods, which significantly improve after a specific low nickel-content diet. The etiopathogenetic role of nickel in the genesis of systemic disorders is, furthermore, demonstrated by the relapse of previous contact lesions, appearance of widespread eczema and generalized urticaria-like lesions after oral nickel challenge test. The aim of this study is to investigate the safety and efficacy of a specific oral hyposensitization to nickel in patients with both local contact disorders and systemic symptoms after the ingestion of nickel-containing foods. Inclusion criteria for the recruitment of these patients were (other than a positive patch test) a benefit higher than 80% from a low nickel-content diet and a positive oral challenge with nickel. Based on the previous experiences, our group adopted a therapeutic protocol by using increasing oral doses of nickel sulfate associated to an elimination diet. Results have been excellent: this treatment has been effective in inducing clinical tolerance to nickel-containing foods, with a low incidence of side effects (gastric pyrosis, itching erythema).

Oral rush desensitization with tomato: a case report.

Adverse food reaction in which no immunological mechanism is demonstrated should be termed nonallergic food hypersensitivity or food intolerance. We present the case of a 12-year-old girl with a clinical history of abdominal pain, nausea, and general malaise after tomato intake which completely remitted with antihistamines. The patient underwent a complete allergy evaluation: skin prick tests, serum specific IgE and IgG4 tests to tomato, and double-blind placebo-controlled food challenge. Skin prick tests and specific IgE to tomato were negative while the food challenge was positive. At the end of the workup, the patient underwent an oral rush desensitizing treatment. At the end of the treatment the patient could eat a maintenance dose of 100 g of tomato daily with no side effects at all. This successful result suggests that the oral desensitizing treatment can be used in patients with nonallergic food hypersensitivity.

An attempt of specific desensitising treatment with gliadin in celiac disease.

Gluten-free diet is the current treatment of celiac disease. We decided to verify the occurrence of histological and serological modification and/or clinical manifestations during a gradual and progressive introduction of gliadin in the diet and if it may induce a tolerance to food, as it occurs in allergic patients. We studied the case of a celiac woman with complete clinical and histological remittance after 10 years of gluten free diet. She took increasing daily doses of gliadin, reaching the final dose of 9 g of gliadin (15 g of gluten) in 6 months. Then she started a free dietary regimen. During the 15-month follow-up period esophago-gastro-duodenoscopy showed normal Kerckring folds and villi. Anti-gliadin, anti-endomysium and anti-tissue-transglutaminase antibodies, as well as the haematological and biochemical parameters remained normal. Our results represent a new approach in research concerning celiac disease, and could provide a future line of study for its management.

Positive patch tests to Euro coins in nickel-sensitized patients.

BACKGROUND: Many efforts have been made to prevent nickel allergy, the most frequent contact allergy in industrialized countries, by identifying acceptable limits of exposure. Even though coins are not covered by the EU Nickel Directive, some authors suggest that nickel release from coins during handling may elicit contact dermatitis in nickel-allergic people. OBJECTIVES: To evaluate sensitivity to nickel released from coins in nickel-allergic patients and to verify whether nickel release from the new Euro coins may elicit stronger cutaneous reactivity than from old Italian lire coins. METHODS: Twenty-five nickel-allergic patients were patch tested with 1- and 2-Euro coins, 1-, 2- and 50-Euro cent coins, and 100 and 500 Italian lire coins. Ten healthy nonnickel-allergic control individuals were also tested. RESULTS: Nineteen patients had positive patch tests to 1- and 2-Euro coins. One was also positive to 1- and 2-Euro cent coins, four to 50-Euro cent coins, and 13 to the 500-lire coin. None had a positive patch test to the 100-lire coin. The number and degree of positive patch tests to coins were related to nickel content. CONCLUSIONS: Euro coins may be potentially more dangerous than old Italian coins. Coins containing little or no nickel should be chosen for coinage to prevent sensitization and to avoid exacerbation of contact dermatitis in nickel-allergic patients.

Demonstration of an IgE-mediated immunological pathogenesis of a severe adverse reaction to gadopentetate dimeglumine.

In this case report, the authors, after reviewing the literature data about contrast agents in Magnetic Resonance Imaging (MRI) and correlated problems, investigate the immunological mechanism of an adverse reaction to gadopentetate dimeglumine (Gd-DTPA), in order to demonstrate an IgE-mediated immunological pathogenesis. The case of a patient who underwent MR imaging in our hospital was studied. During, and after, the MR examination with Gd-DTPA the patient showed local warmth/pain to the external genitalia and to the face, tachycardia, nausea, vomiting, diarrhea, uterine cramps, and diffuse cutaneous rash. Skin tests (intradermal) and the passive transfer test according to Prausnitz and Küstner were positive, suggesting the involvement of an I-type allergy (IgE-mediated) mechanism. In this paper, we demonstrate that the adverse reactions to Gd-DTPA can be supported by an immunological mechanism.