Effective allergen avoidance at high altitude reduces allergen-induced bronchial hyperresponsiveness.

We studied the effects of reduced allergen exposure on bronchial hypereactivity (BHR) in two groups of asthmatic children allergic to house dust mites (HDM) living at high altitude for 9 continuous mo. In the first group the serum levels of total and HDM-specific IgE showed significant decreases after 3 mo (p < 0.001 and p < 0.02, respectively) and after 9 mo (p < 0.001). Three months after returning home the total IgE levels had increased significantly (p < 0.001). The mean percentage fall in peak expiratory flow after exercise testing improved after 3 and 9 mo (p < 0.05), but it had deteriorated after 3 mo at home (p < 0.01). The methacholine PD20-FEV1 increased after 3 mo (p = 0.001) and further after 9 mo (p < 0.001), with a decrease after the 3-mo period at sea level (p = 0.01). In the second cohort there was a significant increase in HDM PD20-FEV1 after 6 and 9 mo (p < 0.001), with a slight decrease of magnitude of the allergen-induced late reaction. Histamine PD20-FEV1 significantly increased after 6 and 9 mo at high altitude, particularly in the challenges performed after the HDM bronchial provocation (p < 0.01). Our data demonstrate that allergen avoidance in asthmatic children not only decreases nonspecific BHR but also decreases allergen sensitivity, late allergen-induced bronchial reactions, and enhancement of BHR by allergen challenge.

Comparison of the effects of inhaled calcium antagonist verapamil, sodium cromoglycate and ipratropium bromide on exercise-induced bronchoconstriction in children with asthma.

Fifteen children with exercise-induced asthma (EIA) participated in a double-blind trial comparing the protective effects of inhaled sodium cromoglycate (20 mg/2 ml), ipratropium bromide (500 micrograms/2 ml) and verapamil (5 mg/2 ml). Saline was used as control. There was no significant difference in base line pulmonary function before and after the administration of each agent. After exercise the maximal percentage fall in the forced expiratory volume in 1 s (FEV-1) (means and SD) were 40.9 +/- 17.2 after inhalation of saline, 15.3 +/- 11.7 after sodium cromoglycate, 36.2 +/- 21.4 after verapamil and 21.7 +/- 17.7 after ipratropium bromide. The inhibitory effects of sodium cromoglycate and ipratropium bromide were significant whereas verapamil failed to produce any effect. To see if a double dose of verapamil is more effective, nine different children with EIA were provoked by the same standardized treadmill running after giving a placebo (4 ml saline) and after verapamil (10 mg in 4 ml). Despite the double dose, again verapamil was ineffective even though the protection index doubled that obtained with the lower dose. The results suggest that the calcium antagonist (verapamil) had almost no effect on the prevention of EIA in the children studied.

[Pulmonary fibrosis in children: diagnosis and therapy]. / Fibrosi polmonari in età pediatrica: diagnosi e terapia.

Pulmonary fibrosis is a chronic disorder characterized by inflammation, injury and fibrosis of the alveolar structures and consequent loss of functional alveolar-capillary units. It involves a number of unresolved terminologic, pathogenetic, diagnostic and therapeutic controversies. The key to understanding the disease is the recognition that inflammation is the first event. The staging of the patients, important for correct therapy decision, is made using methods that specifically evaluate the inflammation such as open lung biopsy, bronchoalveolar lavage, and Gallium 67 scanning. The most rational therapeutic approach is to suppress the inflammation and to prevent further injury and scarring. The drugs of choice for treatment are corticosteroids (prednisone particularly). It is suggested to use large doses during the initial portion of the therapeutic trial followed by a tapering of the dose. If the patient does not respond to corticosteroids other immunosuppressive agents can be considered, particularly cyclophosphamide. The frequency and duration of response to these regimens remains to be defined.

The efficacy of ketotifen in a controlled double-blind food challenge study in patients with food allergy.

The effectiveness of oral ketotifen was compared with that of placebo in 26 patients with food allergy in a randomized, double-blind parallel study. Patients were selected on the basis of food allergy as established by history, clinical improvement after an exclusion diet, and reappearance of the symptoms after a challenge with the food. Thirteen patients were given ketotifen and 13, placebo. Ketotifen or placebo were administered twice daily for 1 month after the first oral provocation test and the last dose was given 12 hours before the second oral provocation test. Ketotifen protected patients (7/13) significantly more than placebo (2/13; P less than .05). The results of this study suggest that ketotifen may be useful for some patients with food allergy.

Biphasic (early and late) asthmatic responses to exercise in children with severe asthma, resident at high altitude.

Twenty-three children with severe asthma who had been resident at high altitude for at least 3 months, considerably reduced their requirement for regular anti-asthma therapy. On a standard exercise challenge in low humidity, ten had no response, seven had isolated immediate bronchospasm and six had biphasic responses with immediate bronchospasm followed 4-10 h later by a late reaction sustained for at least 2 h. The existence of biphasic responses after exercise, similar to those observed after antigen challenge, supports the concept of mast cell involvement in exercise-induced asthma.

Preliminary report on histamine release, circulating immune complexes, and complement activation in children with atopic dermatitis after oral challenge with milk and egg antigens.

The effects of dietary restriction and food challenge were evaluated in five children with atopic dermatitis, as a possible predictive marker for the dietary management of this clinically perplexing disease. Two of the five showed significant elevation of plasma histamine; an additional two demonstrated the presence of immune complexes and in the fifth no change was described. The results of these study lend further support to the causal relationship between food allergy and atopic dermatitis, and suggest that the use of these immunologic parameters may be useful in the clinical assessment and management of these patients.

Adrenocortical function during prolonged treatment with clobetasone butyrate in children with chronic atopic dermatitis and elevated IgE levels.

Twelve children with chronic atopic dermatitis and elevated IgE levels (age range: 2-13 years; mean age = 8.2 +/- 3.5 years) were selected for the study and treated with clobetasone butyrate (0.05% cream) thrice daily during the first week, then twice daily for three weeks. Adrenocortical function was evaluated at the beginning and the end of treatment period. The results show that there was no statistically significant change in adrenal function during the study period (tetracosactrin test). The results of the immunological studies, namely total IgE using the paper disc radioimmunoassay technique, specific IgE using the radioallergosorbent test and immunoglobulin levels are given.

Pulmonary function and bronchial hyperreactivity in asthmatic children with house dust mite allergy during prolonged stay in the Italian Alps (Misurina, 1756 m).

The effects of high altitude were evaluated in 14 children with allergic bronchial asthma over an 8-month period. Clinical improvement, as assessed by decreased bronchial lability, was demonstrated by pulmonary function studies. There was a decreased requirement for drugs and steroids were discontinued in our children. The results of this study suggest the use of this approach as a possible adjunct to the management of refractory cases of bronchial asthma.