Comparison of the Quintest to the lancet in allergic skin testing.

Many skin testing devices have been commercially available over recent years, but use has been limited because of significantly greater costs of such devices. Therefore, the lancet continues to be the most widely used skin testing device in Australia. This study compared performance of another multitest device, the Bayer Quintest to the Becton Dickinson Microlance. Nineteen atopic volunteers were skin tested using histamine dihydrochloride 10 mg/ml, glycerosaline and eight allergens. In 190 tests, 6 discrepancies between the Quintest and Microlance occurred. The Microlance produced slightly larger wheals than the Quintest, reaching statistical significance in 3 allergens. We found the Quintest comparable to the Microlance in concordance of positive and negative allergen responses and in wheal size. The Quintest had higher acceptability to both participants and staff for comfort, ease of use and safety. The Quintest's major advantage is the ability to rapidly screen large numbers of subjects, especially during clinical trials. The major limitation is it's cost.

Comparative effects of loratadine and azatadine in the treatment of seasonal allergic rhinitis.

The efficacy and safety of loratadine 10 mg once daily were compared with azatadine 1 mg twice daily in controlling symptoms of seasonal allergic rhinitis. The study was a randomized, double-blind, parallel-group design involving 34 patients receiving either loratadine or azatadine for 14 days. Both treatments were effective in relieving the histamine-mediated symptoms of seasonal allergic rhinitis. At baseline, 100% and 93% of the patients in the loratadine and azatadine treatment groups, respectively, had moderate or severe symptoms of disease; at endpoint of treatment 80% of the patients in the loratadine treatment group and 92% of those in the azatadine treatment group had mild or no disease symptoms. Sedation was reported by fewer patients in the loratadine treatment group than in the azatadine group. Thus loratadine is an effective and safe antihistamine when given once daily for the symptomatic relief of seasonal allergic rhinitis.

Anaphylactoid reactions to local anaesthetics despite IgE deficiency: a case report.

The mechanisms involved in adverse reactions to local anaesthetic (LA) agents are poorly understood. True IgE-mediated reactions appear to be rare. We report a patient with panhypogammaglobulinemia who developed anaphylactoid reactions to two different LAs (lignocaine and procaine), associated with positive intradermal skin tests to these agents as well as prilocaine, despite absent detectable IgE in the serum and a negative RAST test to procaine. We conclude that direct histamine release induced by LA is likely to be the major mechanism in this case.