Allergy
-
Insect sting challenge in 14 patients with urticarial reaction to last insect sting resulted in two systemic reactions (95% confidence limits 0-6 patients), a reaction rate of 14%. Skin prick test, basophil histamine release, RAST, and allergen-specific IgG, alone or in conjunction, could not indicate the patients to react systemically after sting challenge. Further, the systemic reactions were uninfluenced by type of insect and time elapsed since last insect sting. It is concluded that the reaction to future insect stings cannot be predicted by the immunological tests presently available.
-
Mucosal biopsies from the pharynx, right main stem bronchus and right lower lobe were obtained during flexible fiberoptic bronchoscopy and were examined with light microscopy (LM) and electron microscopy (EM) in 10 asthmatics after 11 months' (range 7-15 months) treatment with high doses of inhaled budesonide via the Nebuhaler, i.e. 1600 micrograms daily. Results were compared with biopsies from 10 controls suspected of having focal, malignant lung diseases. Visual inspection of the tracheobronchial tree showed no signs of atrophy, ulcerations or thrush patches, and LM and EM showed no specific signs of mucosa and connective tissue atrophy; however, epithelial desquamation was seen in the asthmatics. No complications were observed.
-
The combining site specificities of IgE antibodies that react with the oral antibacterial agent trimethoprim and found in the sera of two subjects who experienced anaphylaxis after taking the drug, were investigated. Hapten inhibition studies with some close analogues of trimethoprim and a range of other structurally related compounds showed that the allergenic determinant complementary to the IgE antibodies in the serum of one of the subjects was the 3,4-dimethoxybenzyl group. ⋯ Thus, as with thiopentone, but unlike the neuromuscular blocking drugs, the trimethoprim molecule has more than one determinant each with the capacity to provoke IgE formation, interact with the antibody combining site and provoke drug-induced allergic reactions. The general approach set out here employing carefully selected structural analogues in hapten inhibition studies should be invaluable for confirming specificity and identifying allergenic determinants in IgE antibody-mediated allergic drug reactions.
-
Cat flea sensitivity is considered one of the most important skin diseases in cats and dogs. Cat fleas, however, are also a growing allergen problem for humans. Cat flea-specific IgE antibodies were studied in serum samples from 70 patients with suspected cat allergy, using RAST-based techniques and the nitrocellulose immunoblotting method. ⋯ The nitrocellulose immunoblotting experiments were in agreement with the RAST results showing specific IgE to cat flea. The results indicate that some cat-allergic patients have specific IgE both towards cat and cat flea but also that some of the patients with suspected cat allergy might have specific IgE towards the cat flea and not the cat. RAST-inhibition and immunoblotting experiments also indicate that the allergen composition of cat flea extract differs from that of cat extract, even if common allergens have been detected, leading to cross-reactivity in some sera.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of a new lancet and a hypodermic needle for skin prick testing.
Skin prick tests with a standard allergen panel were carried out in duplicate (one on each arm) on all patients referred to an allergy out-patient clinic. A new lancet with 1-mm point length and a disposable hypodermic needle were used. Patients were randomized to lancet-needle, lancet-lancet, or needle-needle, and the skin prick tests were done by experienced or inexperienced nurses. ⋯ For both lancet and needle a significant difference was noted when comparing experienced versus inexperienced investigators' reproducibility expressed as coefficient of variation. There was no significant difference in reproducibility when comparing lancet and needle results, and no significant difference in wheal size when comparing with histamine references. Surprisingly, the reactions on left arms were generally larger than those on right arms.