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Allergy to fresh fruits and vegetables is IgE-mediated. Its main clinical features are local, such as oral pruritus and swelling of lips and tongue but systemic symptoms such as urticaria, asthma, or anaphylactic shock may occur. Clinical associations with allergic rhinitis due to cross-reactive antigens of pollens and foods are frequent.

The sensitivity and specificity of the Pharmacia CAP System, a new in vitro assay for measuring IgE antibodies, were evaluated in a multicentric study on 286 allergic patients and 243 normal subjects. Sensitivity was 95.5%, with results significantly better than RAST for some allergens, and specificity was excellent, 98.1%.

The behaviour of some immunologic parameters was studied in order to explain the presence or the lack of symptomatology in subjects with IgE specific to foods. In particular, we compared the levels of serum and salivary IgA and IgE antibody specific to apple in 33 patients allergic to birch and with anti-apple IgE, of whom 24 had oral allergy syndrome after eating apple and nine were apple tolerants. We found no differences in the IgE-related parameters such as levels of anti-apple IgE antibody in serum and secretions, mean size of apple skin prick test, and number of patients with a positive histamine release from peripheral basophils stimulated by apple. Similarly, we detected no statistically significant differences in serum and salivary total IgG and total anti-apple IgA antibody of the two groups. We could, however, observe a significantly higher anti-apple salivary IgA/anti-apple serum IgE and anti-apple salivary IgA/anti-apple serum IgA ratios and a significant correlation between the same parameters in tolerant patients when compared with the intolerants. These results seem to suggest that the presence of appropriate levels of secretory anti-apple IgA associated to anti-apple IgE might be one of the factors playing a key role in the prevention of clinical symptoms in atopic subjects.

Twenty-eight subjects affected by perennial asthma were selected in order to investigate the possibility of inducing or relieving an asthmatic attack by means of suggestion. Twenty-five were positive to methacholine challenge test and, among them, eleven reacted to an ultrasonic nebulized distilled water test. The effect of suggestion on airway response was assessed by eight inhalations of normal saline at 32 degrees C alternately presented as a bronchoconstrictor or as a bronchodilator drug. Eight inhalations of the same diluent without any psychic stimulus were used as control test. Seven patients reacted with bronchoconstriction to both positive and negative suggestion and to control test. Further, this group of patients showed a lower methacholine PD20 when compared with the other subjects. In this study, the effects of suggestion on bronchial reactivity were not observed and bronchoconstriction belonged to an individual hyperreactivity of the airways.

Twenty-four adult patients with adverse reactions to foods and food additives took part in a double-blind crossover study to compare the efficacy of oral sodium cromoglycate, 1600 mg daily, with placebo. Duration of treatment was eight weeks. There were statistically significant differences (p less than 0.01) in favor of active treatment as assessed by patients' diary card scores during the last week of treatment. Few side effects were observed. Oral sodium cromoglycate appears to be both effective and well tolerated in the treatment of food allergies, particularly when used in conjunction with a maintenance elimination diet.

In 197 patients with perennial rhinitis, 49 patients (24.9%) were found to be allergic to perennial inhalant allergens, 37 patients (18.8%) allergic to seasonal allergens, 52 patients (26.4%) had food intolerance, 12 patients (6.6%) showed evidence of nasal infection, and in 46 patients (23.3%) etiology was undetermined.

Previous studies have shown that suggestion may modify bronchial reactivity to both inactive diluents and pharmacologically bronchoconstrictor or dilator substances. In our study, 14 patients were subjected to two methacholine challenge tests presented, respectively, as a bronchoconstrictor or as a bronchodilator drug. Forced expiratory volumes in one second were recorded and a PD20 was determined. No significant differences were reported in PD20 values of each patient after the two kinds of suggestion.

Twenty patients with chronic urticaria exacerbated by aspirin or tartrazine were challenged with the offending substance after pre-treatment with either oral sodium cromoglycate or placebo in a double-blind, crossover study. The sequential vascular response test (SVR) described by Fisherman and Cohen 1-4 was used to assess response to challenge. Eighteen patients were protected by oral sodium cromoglycate and one by placebo, taking as a positive response an increase in the bleeding time of 100% or more over control values.

The distribution of T cell subsets has been studied by means of OKT monoclonal antibodies in 19 children with atopic dermatitis. In these patients a decreased percentage of circulating OKT4+ cells has been observed, while no difference has been found between atopic and normal subjects, regarding the percentages of circulating OKT8+ and OKT11+ cells. An increased OKT4+/OKT8+ ratio has been detected only in three children with a particularly severe and extensive atopic eczema.

Nasal challenge and intradermal injection with substance P (SP) were performed in five normal subjects and in five patients suffering from allergic rhinitis. No clinical symptoms, local histamine release, or modifications of nasal airway resistance were observed when SP was insufflated in the nose. Conversely, intradermal injection with SP caused a wheal and flare reaction in all the studied subjects. The different response to SP is likely to be due to the heterogeneity of human skin and nasal mucosa mast cells as far as sensitivity to histamine-releasing agents is concerned. Our findings indicate that SP has no relevant effect on human nasal mucosa, even if a synergetic action of SP with other allergic mediators cannot be excluded. The role of SP in the pathogenesis of allergic diseases in humans remains to be defined and deserves further study.