[Quality control in the allergy laboratory--4 years "Allergy Ring Trial" in Austria]. / Qualitätskontrolle im Allergielabor--4 Jahre "Ringversuch Allergie" in Osterreich.

In 1988 the Austrian Society for Allergology and Immunology initiated an external quality control program for the in vitro allergy diagnosis. In 12 mailings, 62 sera from allergic patients were sent to selected laboratories in order to determine total and antigen specific IgE according to the laboratory-specific methods. The values for total IgE varied considerably (73.9% were within +/- 1 SD, 94.3% within +/- 2 SD and 99.1% within +/- 2 SD, but only 0.9% beyond that). Sources of error were mainly attributable to inappropriate equipment and low quality reagents, but also bad test performance, with respect to personnel and the routines. In contrast, antigen specific IgE against pollen, mites, moulds, insect venoms, animal danders, drugs, parasites, environmental and food antigens revealed quite homogeneous results. Out of 1492 data, only 46 (3.1%) had to be declared as "wrong", and the variability of the RAST-classes was low. Whereas the quality of the reagents from all the different suppliers was not absolutely reliable at the beginning of the study, it improved considerably with time, as consequence of our complaints. The comparability of the methods for detecting total-IgE were non-satisfactory, whereas those for antigen specific IgE were generally good. The variety of methods employed (radio- and enzyme immunologic, fluoro- and nephelometric methods, etc.) should entail appropriate consequences, especially critical comparisons within one and the same laboratory; in addition, international standardization of the "normal" values should replace company-standards, and quality control programs for each test system before it is marketed should be mandatory. Our results confirm, that external control should be obligatory for any laboratory.(ABSTRACT TRUNCATED AT 250 WORDS)

[Food allergies and pseudo-allergies--mechanism, clinical aspects and diagnosis]. / Nahrungsmittelallergien und -pseudoallergien--Mechanismen, Klinik und Diagnostik.

Allergic and pseudoallergic reactions caused by foods respectively food-additives present cutaneous (urticaria, erythrodermia), gastrointestinal (nausea, vomiting, diarrhoea) and respiratory symptoms (allergic bronchial asthma). The anaphylactic shock is the most severe manifestation. Exact diagnosis is based on anamnesis, skin-tests, laboratory investigations, dietetic test procedures and oral provocation. In allergic and pseudoallergic reactions the adequate therapy is the avoidance of the causative agent (diet).

[The value of positive epicutaneous test reactions to 4,4'-diaminodiphenylmethane]. / Zur Wertigkeit positiver Epikutantestreaktionen auf 4,4'-Diaminodiphenylmethan.

This study was undertaken to determine the significance of positive patch test reactions to 4,4'-diaminodiphenylmethane (DDM). Data of 202 DDM-positive patients concerning age, sex and profession, type, localisation and duration of eczema and combined allergens were evaluated. The results obtained were compared by chi-square-test with those of 3397 consecutive, unselected contact dermatitis patients with negative reactions to DDM. The most conspicuous results were: 1. The positive patch test reaction to DDM is usually a marker for allergy to p-amino-compounds. 2. 39/202 patients showed isolated positive test reactions to DDM. The source of the allergen remained unclear. 3. Workers in chemical laboratories seem to have an increased risk for acquiring DDM-allergy. 4. The clinical relevance of DDM-allergy could only be proven in a few patients.

Asthma caused by bromelain: an occupational allergy.

Bromelains consist of a group of proteolytic enzymes of Bromeliaceae. They are commonly used in pharmaceutical industries, food production and in diagnostic laboratories. Bromelains are known to cause IgE-mediated reactions of both the immediate type and the 'late phase reaction of immediate type reaction' with predominantly respiratory symptoms. We report four cases of occupational allergy to bromelain in workers of a blood grouping laboratory. These observations prompted us to investigate the sensitization rate to bromelain in all workers of the particular diagnostic laboratory who had contact with bromelain. These results were compared with those obtained from healthy, randomly selected individuals without evident bromelain exposure. Our findings indicate that (i) bromelain is a strong sensitizer, (ii) sensitization usually occurs due to inhalation and not to ingestion, (iii) bromelain allergy is occupationally acquired, and adequate precautions are necessary. We can further state that (iv) skin testing with relatively pure allergens such as isolated proteases like bromelain may induce systemic reactions, even at very high dilutions.

[Allergic contact eczema caused by an acetone-formaldehyde condensate in billboard workers]. / Allergisches Kontaktekzem durch ein Aceton-Formaldehyd-Kondensat bei Plakatierern.

We report two cases of occupational contact dermatitis in billboard workers due to employment of a new paste additive. Clinical picture, patch test result, histological pattern of the test reaction and course of the disease indicate that the observed eczema are manifestations of contact allergy and do not represent irritant-toxic dermatitis. The glue is a hydrous solution of a heterogeneous mixture of condensation products of acetone and formaldehyde with a small part of free acetone and formaldehyde. Exact determination of the allergen and identification of the substance group failed. The allergen seems to be a strong sensitizer.

[Allergic bronchial asthma caused by bromelin]. / Allergisches Asthma bronchiale durch Bromelin.

The proteolytic enzymes of Bromeliaceae (bromelin) are commonly used in pharmaceutical industries, food production and diagnostic laboratories. We report two cases of occupational allergy to bromelin with predominantly respiratory manifestation (allergic bronchial asthma). Obviously sensitisation to bromelin usually takes place due to inhalation and not due to ingestion.

[Allergic contact eczema caused by trifluorothymidine]. / Allergisches Kontaktekzem durch Trifluorthymidin.

Over the past years pyrimidine analogues have gained an important role within the concept of local therapy of viral infections, in particular in the field of ophthalmology. This report deals with a case of contact allergy to trifluorothymidine in a 15 year-old atopic patient. Since until now only a small number of contact allergic reactions have been reported, the halogenated pyrimidine analogues seem to be weak sensitizers. Cross reactivity within these substances may occur.

[Change in the allergen spectrum in contact eczema 1975-1984]. / Zur Anderung des Allergenspektrums bei Kontaktekzemen in den Jahren 1975-1984.

The patch test results in 8247 patients tested in the years from 1975 to 1984 at the Department of Dermatology at the University of Graz were evaluated and a trend analysis was performed. The most conspicuous results were: Increase of contact allergy to nickel in young women; Decrease of contact allergy to chromate; Frequent occurrence of contact allergy to 4,4-diaminodiphenylmethane.

[Oral provocation of a hydroxyquinoline eczema. Hematogenic contact eczema from hydroxyquinoline]. / Orale Provokation eines Hydroxychinolin-Ekzems. Hämatogenes Kontaktekzem auf Hydroxychinolin.

We inform about an eczema reaction from inside after perception of Reasec Plus. This hydroxyquinolin substance caused a generalized dermatitis at a patient who is contact sensibilized against Vioform. The sensitivity index found out among our patients is very little (0,85%). The probability for the appearance of an internally or externally induced contact dermatitis after perception of Hydroxyquinolin is rather poor.

Determinations of penicilloyl specific IgE antibodies for the evaluation of hypersensitivity against penicillin.

Results from skin tests and radioallergosorbent test (penicilloyl G and penicilloyl V) were compared in 76 patients with suspected penicillin hypersensitivity and in 22 control subjects without such clinical symptoms. The test results were also correlated to the clinical history of adverse reactions and to the levels of total serum IgE. The overall agreement between skin test and RAST results was 89% in the patient group. Two of the control subjects without symptoms were professionally employed with penicillin production; one of them had circulating IgE-antibodies and the other exhibited positive skin tests. The skin tests were more frequently positive than the RAST test. By means of skin titration some of the skin tests were demonstrated to be false positive. The discrepancy can also be explained by the fact that skin reactions also occur in other situations than IgE-mediated adverse reactions. Circulating IgE-antibodies were not found in any of 23 cases where adverse reactions appeared later than 24 h after the latest penicillin administration. It is concluded that the measurement of circulating IgE-antibodies is a valuable aid in the diagnosis of penicillin allergy.