Skin testing in patients with high risk of anaphylactic reactions to penicillin.

Sequential skin testing including immediate patch test (IPT), skin prick test (SPT), and intradermal test (IT) with sodium benzylpenicillin G (Pen G), and SPT with benzylpenicilloyl human serum albumin (BPO-HSA) was done in 58 subjects with a history of probable anaphylactic reaction or shock of unknown cause. Based on positive skin tests, the diagnosis of penicillin anaphylaxis was confirmed in 30 patients. The average age of onset of penicillin allergy was 42 years ranging from 20-70 years. The sex ratio was 2:28 with marked female predominance. Anaphylactic shock, wheezing and urticaria occurred in 21, 20, 19 patients, respectively. Most symptoms were induced by skin tests and inhalation. The results of skin tests in these patients showed that IPT with 500 U/ml of Pen G was not only reliable but also safe. It is suggested that patients suspected of penicillin anaphylaxis should received IPT with 500 U/ml of Pen G as the initial diagnostic step; if a negative reaction occurred, then SPT and IT should be applied with the same concentration of Pen G, until a positive reaction developed or all the skin testing showed negative results. SPT to BPO-HSA was safe, but its positive rate was only 47.8% in our study; it seems to be less important than skin test to Pen G. As a whole, the skin testing procedure we recommend is relatively reliable, safe and practical even in individuals extremely sensitive to penicillin. In addition, once the patient develops a positive IPT, Pen G residue on the testing site should be wiped away rapidly and washed out with cool water thoroughly to disrupt further violent reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergenicity of orange juice and orange seeds: a clinical study.

Oranges are considered to be common allergenic fruits in China. They may induce severe food allergy in sensitive individuals. Allergic histories were analyzed in 26 orange-sensitive patients. Intradermal tests with extracts of orange juice and seeds were performed in 16 out of the 26 patients. P-K test was performed in one patient. The allergic history analysis suggested that clinical symptoms of some orange-allergic subjects were different from other fruit allergies but similar to nut and other oil plant seed allergies. The skin test and P-K test showed that the major allergenic components of orange reside in orange seeds instead of orange juice. Systemic reactions developed in 5 patients after intradermal tests with 1:20-200 (w/v) orange seed extracts. We considered that orange seed contains high potent allergens which may induce orange sensitivity due to careless chewing of orange seeds.

An investigation on in vivo allergenicity of Artemisia annua leaves and stems.

Pollen of Artemisia annua is considered to be one of the most important allergens in autumnal hay fever in China, just as ragweed is in North America. In order to clarify the allergenicity of non-pollen containing components of the plant, Artemisia annua leaves and stems were collected and extracted before pollination time. The extracts of these pollen-free plant components were studied for allergenic activities using skin prick tests, intradermal tests, intranasal challenge and bronchial provocation tests. In 52 subjects sensitive to Artemisia pollen, 92.3% gave positive responses in skin prick tests, 100% gave positive responses in intradermal tests, 66.7% gave positive responses in intranasal challenge and 59.3% gave positive responses in bronchial provocation tests. Negative results to skin prick tests, intradermal tests and bronchial provocation tests were revealed in 30 seasonal asthmatics who gave negative responses to the pollen skin tests. Strict placebo control showed all negative tests in non-atopic adult human volunteers. We concluded that pollen-free plant extracts did have in vivo allergenic activities. Analysis of the plant allergenic components in vitro will be the subject of further studies.

One year observation of immunotherapy for Artemisia hay fever in China: a clinical and immunological study.

A controlled trial of one year immunotherapy was conducted in 50 Artemisia-sensitive hay fever patients (treatment group). From October 1985 to July 1986, all of the treatment group patients received one year regular injection of Artemisia pollen allergen extract totalling 30,000 protein nitrogen units (PNU). For these patients, symptom score indices of the posttreatment 1986 pollination season were compared with those from the pretreatment 1985 season and also with the scores of a similar group of 30 Artemisia-sensitive patients treated only with symptomatic medications during the 1986 season (control group). The 1986 symptom scores to the treatment group were significantly improved and the effective rate was 78%. Immunological study with the Human Basophil Degranulation Test (HBDT) showed a significant decrease in degranulation reactions after immunotherapy. Moreover, The decline of the HBDT positive rate in the treatment group was significantly greater in patients with improved symptoms than patients with unchanged symptoms. No difference was observed in basophil degranulation in those patients tested with a pollen-free plant extract, which was not applied in immunotherapy. The results suggested that immunotherapy could induce desensitization of basophils and that the induction might be allergen specific. Basophil desensitization may play an important role in the mechanism of immunotherapy.

The effect of sodium crompromate in the prevention of exercise-induced asthma.

Sodium crompromate (SCP) is an isomer of disodium cromoglycate (DSCG). The two chemicals are pharmacologically similar but with different chemical synthesis. A comparative double-blind latin square study of the preventive effect of SCP and DSCG versus a placebo aerosol was carried out on a group of nine cases of exercise-induced asthma (EIA). Compared with the placebo, both SCP and DSCG were able to prevent asthma under exercise provocation, as monitored by chest auscultation and FEV1. There was no significant difference in the percentage fall of FEV1 on challenge. This suggests that SCP has a similar prophylactic effect as that of DSCG on EIA.