Graham Solley

Penicillin allergy: clinical experience with a battery of skin-test reagents

From 1971 through August 1978, 778 patients underwent penicillin skin testing. Each patient gave a history of previous penicillin allergy. The skin-test reagents consisted of (1) fresh solutions of commercially prepared penicillin G (PEN G), ampicillin (AMP), and methicillin (METH); (2) polylysine conjugates of the major antigenic determinants of each of the three drugs: and (3) alkaline hydrolysates of each drug. A total of 108 (14%) patients showed positive reactions to one or more of the reagents. Certain patients showed reactivity to many reagents, whereas others reacted selectively to only one or two reagents. Addition of reagents of AMP and METH resulted in a greater number of positive reactors than when reagents of PEN G alone were used. Of the group whose skin tests were negative, 290 (43%) were later treated with penicillin, twelve of these (4.1%) had allergic reactions. Eight of the group of whose skin tests were positive were subsequently treated, and four of these (50%) had allergic reactions again. A group 151 patients whose skin tests were negative and 27 patients whose skin tests were positive were treated with a cephalosporin. Only two patients had allergic reactions to the drug: both had had negative skin tests to penicillin. We conclude that the risk of subsequent allergic reactivity to penicillin is much lower if the skin tests are negative than if positive, that testing with semisynthetic penicillins increases the number of skin-test reactors, and that the incidence of allergic reactions is low in patients treated with cephalosporin.

The therapeutic response of urticarial vasculitis to indomethacin

Ten patients with urticarial vasculitis, characterized clinically by persistent painful urticarial lesions, angioedema, recurrent arthralgia, abdominal pain, and low-grade fever, were selected for study. All patients had histologic evidence of leukocytoclastic vasculitis in the urticarial lesions. Results of direct immunofluorescence microscopy of urticarial lesions were positive in all nine of the patients tested. Treatment with indomethacin in dosages from 25 mg three times daily to 50 mg four times daily resulted in complete clearing of all disease manifestations in six of ten patients within 17 days and partial improvement in three. In eight of the ten patients, disease activity recurred within 48 hours after discontinuation of the use of indomethacin. Gastrointestinal irritation was the only side effect noted. Indomethacin is proposed as an effective mode of therapy in a disorder unresponsive to treatment with conventional medications for urticaria, including high-dose corticosteroids.

Hypersensitivity pneumonitis induced by Penicillium species.

An entomologist developed an illness with typical features of hypersensitivity pneumonitis. On-site investigations indicated that on the days of his attacks he was exposed to dust laden with several species of mold, especially Penicillium spp., as well as to mists generated by reservoir-type humidifiers. Serologic tests to more than 40 antigens prepared from organisms and sources known to cause hypersensitivity pneumonitis showed strong reactions to Penicillium and to antigens prepared from the scum of a large industrial humidifier and from his laboratory humidifier. PFTs revealed a significant reduction in DLCO, Following a 4-mo period without laboratory exposure, he experienced no further episodes, a return to his previous exercise tolerance, and a normal DLCO, BP studies with extracts of Penicillium casei and humidifier water from his laboratory (H1) resulted in objective evidence, both clinically and by hematologic and pulmonary function testing, of hypersensitivity to Penicillium spp. and possibly also to the H1 preparation.

An Immunodiagnostic Assay for Quantitation of Specific IgE to the Major Pollen Allergen Component, Pas n 1, of the Subtropical Bahia Grass

Background: Pollens of the Panicoideae subfamily of grasses including Bahia (Paspalum notatum) are important allergen sources in subtropical regions of the world. An assay for specific IgE to the major molecular allergenic component, Pas n 1, of Bahia grass pollen (BaGP) would have immunodiagnostic utility for patients with pollen allergy in these regions. Methods: Biotinylated Pas n 1 purified from BaGP was coated onto streptavidin ImmunoCAPs. Subjects were assessed by clinical history of allergic rhinitis and skin prick test (SPT) to aeroallergens. Serum total, BaGP-specific and Pas n 1-specific IgE were measured. Results: Pas n 1 IgE concentrations were highly correlated with BaGP SPT (r = 0.795, p < 0.0001) and BaGP IgE (r = 0.915, p < 0.0001). At 0.23 kU/l Pas n 1 IgE, the diagnostic sensitivity (92.4%) and specificity (93.1%) for the detection of BaGP allergy was high (area under receiver operator curve 0.960, p < 0.0001). The median concentrations of Pas n 1 IgE in non-atopic subjects (0.01 kU/l, n = 67) and those with other allergies (0.02 kU/l, n = 59) showed no inter-group difference, whilst grass pollen-allergic patients with allergic rhinitis showed elevated Pas n 1 IgE (6.71 kU/l, n = 182, p < 0.0001). The inter-assay coefficient of variation for the BaGP-allergic serum pool was 6.92%. Conclusions: Pas n 1 IgE appears to account for most of the BaGP-specific IgE. This molecular component immunoassay for Pas n 1 IgE has potential utility to improve the sensitivity and accuracy of diagnosis of BaGP allergy for patients in subtropical regions.