Skin testing to detect penicillin allergy

Mechanisms in IgE-dependent anaphylaxis to anesthetic drugs

The discovery of IgE antibodies to neuromuscular blocking drugs, to thiopentone and narcotics, particularly morphine, reinforced earlier beliefs formed from skin test and other clinical findings that many "anaphylactoid" reactions to drugs were true type 1 immediate hypersensitivity reactions. Immunochemical studies established the fine structural specificities of the drug-reactive IgE antibodies and provided an explanation in molecular terms for a number of observed clinical cross-reactions. Subtleties in interpreting relationships between skin tests and IgE radioimmunoassays are pointed out and mechanisms of drug-induced mediator release, persistence of IgE antibodies and the nature of the sensitizing sources are discussed.

Assessment of histamine release from basophils in whole blood by benzylpenicilloyl poly-L-lysine in penicillin-sensitized patients

Histamine release from basophil granulocytes in whole blood by benzylpenicilloyl poly-L-lysine (PPL) was investigated in 7 patients with penicillin allergy. All patients presented with systemic immediate hypersensitivity reactions after i.v. administration of penicillin G. Total histamine (of 7 patients) ranged from 27.5 ng/ml to 62.1 ng/ml (mean 43.2 ng/ml). The spontaneous histamine release ranged from 0.15% to 5.1% (mean 1.8%) of the total content. Addition of PPL in various concentrations resulted in values between 0.8 and 9.6%. Although PPL is a reliable allergen for prick- and intradermal testing in the diagnosis of penicillin allergy--demonstrating a histamine liberation in the skin--the in vitro experiment using the same allergen showed no histamine release above 10%. Using a threshold of 5% out of 7 patients, 4 (57%) would show a positive histamine release. Therefore it might indicate that in penicillin allergy a threshold of 5% must be used. In addition, basophils in whole blood and skin mast cells may be activated differently.

Drug allergy

Although allergic drug reactions are just one type of adverse reaction to medications, they are clinically very important because of the morbidity and mortality they cause. An ever-expanding pharmacopeia increases the potential for allergic drug reactions. An understanding of the types of allergic drug reactions, their immunopathologic mechanisms, and the most likely medications involved; an approach to determine the drug responsible for the reaction; and ways to prevent future allergic drug reactions are important features in minimizing patient morbidity.

Detection of human IgE to sulfamethoxazole by skin testing with sulfamethoxazoyl-poly-L-tyrosine

Adverse reactions to sulfamethoxazole (SMX) occur in 4% to 6% of normal individuals. Many of these reactions resemble immunopathologic reactions, but skin test or in vitro evidence of a role for IgE is limited. Earlier RAST studies in our laboratory provided evidence that the N4-SMX hapten was a major determinant in immediate hypersensitivity reactions to SMX. We tested the hypothesis that IgE to this hapten is present on the mast cells of patients who have experienced immediate hypersensitivity reactions temporally related to exposure to SMX. A multivalent skin test reagent, SMX168-poly-L-tyrosine, and a univalent hapten, SMX-tyrosine, were synthesized. Forty-four patients with histories of allergic reactions to SMX and six subjects who had been exposed to the drug, but who had not reacted, were skin tested. Twenty-seven percent of the history-positive patients were skin test positive. None of the control individuals was positive. The immunologic responses to SMX in three patients who had experienced allergic reactions during SMX/trimethoprim therapy were analyzed in serial skin test and RAST assessments. One to three years after the clinical reactions, IgE to SMX could be demonstrated by skin testing in all three patients with a SMX-poly-L-tyrosine skin test reagent. Skin test reactions were inhibited by the monovalent reagent, SMX-tyrosine, in a dose-dependent manner. SMX-specific IgE antibodies could also be detected by RAST in serum obtained within days of the reactions from two of the three individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-fatal anaphylaxis caused by ampicillin scratch-test. Report of case

A case of non-fatal anaphylaxis due to an ampicillin scratch-test is reported. The test technique and the management of the patient are described. The need to use a low-concentration solution for skin testing, and the value of skin tests in the detection of immediate allergic reaction in patients at risk, are stressed.

Drug allergy

Adverse reaction to drugs is a common problem in the pediatric population. This article discusses the different types of adverse drug reactions and their mechanisms. Also included are representative clinical syndromes of drug hypersensitivity reactions, as well as certain organ systems syndromes. Finally, diagnosis and management of allergic reactions to particular drugs such as penicillin, iodinated contrast dye, insulin, and others are discussed.

Anaphylaxis to amoxycillin but good tolerance for benzyl penicillin. In vivo and in vitro studies of specific IgE antibodies

Three patients are reported on who suffered anaphylactic reactions after amoxycillin (AX) treatment and challenge but tolerated benzylpenicillin (BP) parenterally and orally. Two of the three patients had positive skin tests and RAST to AX reagents but negative responses to benzyl penicilloyl (BPO) specific skin tests and RAST and the minor determinant mixture (MDM) skin test reagent. The third case was negative to all skin tests and RAST. RAST and RAST inhibition on the two positive sera suggest that the response is related to the acyl side chain of AX.

Antibodies to penicillin in children receiving long-term secondary prophylaxis for rheumatic fever

The occurrence of IgE and IgG antibodies to penicillin G and V in children on long-term treatment with penicillin as secondary prophylaxis for rheumatic fever was studied using Phadebas RAST (Pharmacia Diagnostics, Uppsala, Sweden) and ELISA respectively. The duration of the prophylaxis ranged between 1.5 months and 5 years (mean 1.8 years). Of 18 patients who had been given penicillin for more than 1.5 months, two had IgE antibodies and 12 had IgG antibodies to penicillin. Patients with acute rheumatic fever who had not yet received long-term treatment with penicillin had antibodies of the IgG class in two out of 12 cases. The patients gave no history of adverse reactions to the penicillin injections and there were no signs of immune complex-mediated disease. The two children who had IgE antibodies were switched to oral erythromycin instead of the penicillin injections. Penicillin is the drug of choice in the prophylaxis of rheumatic fever and can apparently be safely given as intramuscular injections of depot-penicillin to prevent recurrences of the disease and ensuing cardiac damage.

Allergy to suxamethonium: persisting abnormalities in skin tests, specific IgE antibodies and leucocyte histamine release

Twenty-one patients, who had previously experienced an anaphylactic reaction to suxamethonium during general anaesthesia, were selected for this study. Initially, skin tests with muscle relaxants were carried out in the twenty-one patients, detection of specific anti-choline IgE in nineteen, and leucocyte histamine release in seventeen. These three tests were then repeated between 1 year and 4 years after the initial evaluation. In the majority of patients, sensitization to the muscle relaxants persisted for more than 1 year after the anaphylactic reaction. Only three patients out of twenty-one (4%) had negative skin tests when retested 1-4 years later. A reduction in leucocyte histamine release was noticed in one of the seventeen retested patients (6%). Modifications of anti-choline IgE were observed in five of nineteen patients (26%). The persistence of sensitization to suxamethonium may result from repeated stimulation by occasional contacts with quaternary ammonium compounds. This study demonstrates the reliability of skin tests, leucocyte histamine release and detection of anti-choline IgE to diagnose allergic reactions to suxamethonium, even when they are performed a long time after the initial anaphylactic reaction.

Penicillin in milk--its importance in urticaria

Fifty patients with recurrent urticaria were tested by means of the RAST test for penicillin allergy. Fifteen patients had positive reactions and of these, thirteen received provocation tests with 0.1 U/ml of penicillin in milk. Four had definite positive reactions, three doubtful reactions and six had no reaction. Although there has been improvement in the purity of milk, penicillin residues remain a potential cause of urticaria even in very low amounts and could have contributed to the urticaria in at least 8% of our patients. Veterinary use of antibiotics and food quality should be strictly regulated to prevent contamination of our diet.

Acute and chronic desensitization of penicillin-allergic patients using oral penicillin

The efficacy, safety and mechanisms of penicillin desensitization were studied in 24 adults and two children with serious infections that required therapy with a beta-lactam drug. Indications for desensitization included debilitating as well as life-endangering infections. Increasing oral doses of phenoxymethyl penicillin were administered at 15-minute intervals to a cumulative dose of 1.3 million units. Parenteral therapy with the beta-lactam drug of choice was instituted at that point. Immunologic complications of desensitization or therapy, ranging from pruritus to serum sickness, occurred in 12 patients. The appearance of gradually worsening wheezing led to abandonment of the procedure in one subject with cystic fibrosis and severe pulmonary disease. The remaining 25 patients were successfully desensitized and received full-dose parenteral therapy. Chronic desensitization was maintained in seven individuals with twice daily oral penicillins for 3 weeks to more than 2 years. No allergic complications of chronic desensitization or recurrent full-dose parenteral therapy were detected. Skin test reactions to one or all penicillin determinants became negative in 11 of 15 patients retested after acute desensitization. Two desensitized patients became skin test negative, remained skin test negative after cessation of desensitization, and tolerated subsequent beta-lactam therapy without allergic reactions or resensitization. The results of this study provide new evidence that acute and chronic penicillin desensitization is useful and an acceptably safe approach and suggest that antigen-specific mast cell desensitization contributes to the protection against anaphylaxis.

Studies of human IgE to a sulfonamide determinant

We tested the hypothesis that patients who experience immediate hypersensitivity reactions to sulfonamides (SM) express IgE that can bind to a N4-sulfonamidoyl determinant (N4-SM). Sulfamethoxazole (SMX) was coupled to CNBr-activated cellulose disks to form a matrix predominantly substituted with isourea-linked N4-SMX determinants. After incubation of human sera with these disks or bovine serum albumin substituted disks as a control, the binding of IgE was assessed with 125I-labeled antihuman IgE. The binding ratios (counts per minute SMX disks per counts per minute bovine serum albumin disks) for sera from nonallergic donors and newborn infants averaged 1.11 (+/- 0.21 SD). Sera from 10 patients with histories of apparent immediate hypersensitivity reactions to SM were studied. Ratios greater than or equal to 2.1 (greater than 4 SD above control) were detected in 70% (seven of 10). Significant binding was detected in the sera of three of seven patients with other forms of SM allergy. Preincubation with SMX (80 mmol/L) inhibited binding 7% to 35% in eight of the 10 positive sera tested. Binding of one highly reactive serum was significantly inhibited by SMX, sulfamethizole, and sulfamerazine, but not sulfanilic acid or trimethoprim. The results of this study suggest that N4-SM is a major determinant recognized by IgE to SM and that an in vitro assay capable of detecting IgE to SM has been developed.

Acute desensitization of a patient with cystic fibrosis allergic to both beta-lactam and aminoglycoside antibiotics

A 15-year-old patient with cystic fibrosis developed urticarial reactions to tobramycin, gentamicin, and cephoperazone, and an anaphylactic reaction to ticarcillin during therapy for an extensive pulmonary infection with Pseudomonas aeruginosa and Staphylococcus aureus. Immediate wheal-and-flare skin tests were positive with tobramycin and with penicilloylpoly-L-lysine. Desensitization with tobramycin in gradually increasing intravenous doses was accomplished during 8 hours. The procedure was complicated by a macular rash that remitted within minutes without therapy, but no symptoms or signs of an allergic reaction to tobramycin were detected during full dose therapy. Skin test responses to tobramycin became negative by the end of the desensitization procedure, whereas the responses to penicilloylpoly-L-lysine and histamine remained positive. A worsening course led to an unsuccessful attempt to desensitize the patient to beta-lactam determinants. Wheezing appeared during the administration of oral doses. This case demonstrates the feasibility of acute, antigen-specific desensitization of an aminoglycoside-allergic patient and the failure to achieve a second, simultaneous desensitization. This patient experienced the first serious reaction to oral penicillin desensitization.

Contact dermatitis to semisynthetic penicillins in factory workers

45 workers developed dermatitis after handling semi-synthetic penicillins in a factory. All reacted on patch test, but several agents had to be used. Only 7 reacted to benzyl penicillin. 1/3 reacted to only one allergen, while 2/3 reacted to several. The duration of exposure before symptoms was short, often less than 2 months. 19 had hay fever or asthma, and they developed their symptoms after a shorter exposure time. A survey for airborne antibiotics was performed.

Penicillin anaphylaxis

A case of oral penicillin anaphylaxis is described, and the terminology, occurrence, clinical manifestations, pathogenesis, prevention, and treatment of anaphylaxis are reviewed. Emergency physicians should be aware of oral penicillin anaphylaxis in order to prevent its occurrence by prescribing the antibiotic judiciously and knowledgeably and to offer optimal medical therapy once this life-threatening reaction has begun.

Penicillin allergy and desensitization in serious infections during pregnancy

Penicillin allergy presents a major obstacle to the successful management of some antepartum infections. We studied 15 pregnant women with histories of penicillin allergy confirmed by positive immediate wheal-and-flare skin tests. Thirteen had syphilis, one listeria sepsis, and one Streptococcus viridans endocarditis. Each patient was desensitized over four to six hours by oral administration of increasing doses of penicillin V. At the completion of the procedure, full-dose parenteral therapy with penicillin G or ampicillin was instituted. No extracutaneous reactions were detected. Five of the subjects (33 per cent) experienced pruritus (three) or urticaria (two), but no interruption of desensitization or therapy was necessary. All clinically apparent maternal infections were cured. The pregnancy complicated by listeriosis aborted in the first trimester. The 11 neonates delivered to date are normal. These results indicate that oral desensitization is an acceptably safe approach to therapy in pregnant women who are allergic to penicillin and have infections that require beta-lactam drugs.

A liquid chromatographic study of stability of the minor determinants of penicillin allergy: a stable minor determinant mixture skin test preparation

Various skin test reagents supplying minor determinants for detecting penicillin hypersensitivity have been examined by high-performance liquid chromatography (HPLC) for composition and stability. HPLC systems capable of separating and determining the four diastereoisomers of benzyl-D-penicilloic acid and the two benzyl-D-penicilloic acids were developed for this purpose. The "simple skin test reagent," consisting of an aged partial alkaline hydrolysate of penicillin, is possibly an adequate source of (5R,6R)-benzyl-D-penicilloate whereas the "simple skin test reagent," consisting of aged aqueous solution of penicillin, is a questionable source of this compound. A modified Levine, Voss, Redmond, and Zolov minor determinant mixture (MDM) reagent and the components (5R,6R)-benzyl-D-penicilloate and (5R)-benzyl-D-penilloate have been found to be highly labile in aqueous solution, giving rise to a mixture of diastereoisomers. The tendency to epimerize at C-5 was a prominent feature of (5R,6S)- and (5S,6R)- as well as (5R,6R)-benzyl-D-penicilloic acids. The MDM reagent has been prepared in single-dose ampules as a dried, lyophilized powder that can be stored without change and used as needed. Lyophilized MDM has served as a satisfactory substitute for freshly prepared MDM in several individuals with MDM-positive history and, in a recent clinical study, evaluating the question of penicillin skin test sensitization. This convenient, stable, single-dose form of the MDM reagent should facilitate skin testing for penicillin sensitivity.

Allergic and pseudo-allergic reactions caused by penicillins, cocoa and peppermint additives in penicillin factory workers examined by basophil histamine release

Allergic and pseudo-allergic reactions were examined in penicillin factory workers exposed to the dust of preparations of pivampicillin and pivmecillinam. Among 14 workers basophils from five persons showed histamine release by challenge with penicillins, whereas no release was observed in controls of non-atopic individuals not working with the manufacturing of penicillin. Positive skin response was obtained in four workers by path testing and in three persons by scratch test revealing late but no immediate response. All the eight workers who were also exposed to flavour additives used in the penicillin preparations showed histamine release by cocoa and peppermint. The release was not changed by removal of immunoglobulins from the basophil cell surface and the additives caused a similar release in the controls. The histamine release caused by cocoa and peppermint therefore depend on non-immunological mechanisms, i.e. pseudo-allergic reactions which might contribute to the symptoms in penicillin factory workers.

Allergy to semisynthetic penicillins in cystic fibrosis

Allergic reactions to anti-Pseudomonal penicillin derivatives are an increasing problem in therapy of cystic fibrosis lung disease. We evaluated 15 patients, ages 12 to 37 years, with documented allergic reactions to carbenicillin, ticarcillin, or piperacillin. Intradermal skin test reactions were positive for benzylpenicillin in seven patients, penicilloyl-polylysine in one, and ticarcillin or piperacillin in eight, for a total of 11 of 11 tested. Results of radioallergosorbent testing to penicilloyl conjugates were positive in eight of 14 patients and equivocal in four others. Overall, skin tests or RAST results were positive in 13 of 15 patients. All patients were desensitized with a semisynthetic penicillin by continuous serial intravenous infusion of 10-fold dose increments, beginning with 10(-6) of the therapeutic dose. Desensitization was successful in 25 of 26 instances. After intravenously administered therapy, maintenance of desensitization with dicloxacillin orally was unsuccessful in four of six patients. We conclude that (1) allergy to semisynthetic penicillins in cystic fibrosis usually is IgE mediated; (2) such allergy can be evaluated by skin testing; (3) it can be safely and in most cases successfully treated by intravenous desensitization; and (4) allergic patients should be desensitized on each subsequent admission for intravenously administered therapy.

Routine elective penicillin allergy skin testing in children and adolescents: study of sensitization

This study aims at evaluating the possibility in children and adolescents of (re)sensitization to penicillin that could result from skin test and challenge. Patients (240) with a history of a reaction to penicillin or one of its analogs were skin-tested with penicillin G, commerical benzlpenicilloyl polylysine, and a minor determinant mixture consisting of sodium benzylpenicilloate and sodium benzylpenilloate. The patients were tested when well, in no immediate need for penicillin, and during a routine office visit. Twenty-one (8.75%) patients had one or more positive skin tests. Three (14%) of the positive reactors reacted only to the MDM mixture, with one reacting only to the benzylpenilloate component. Of the patients with negative skin tests, 219 were given a 10-day course of oral penicillin. Three (1.4%) of the patients developed a-mild skin exanthem 7 to 10 days after starting the penicillin. All skin test-negative patients were retested 4 wk or more after completion of the oral challenge. Only two patients (less than 1%) who tolerated an oral challenge of penicillin had a positive skin test upon retesting. We believe that the described penicillin allergy testing procedure in children and adolescents with a history of allergy to penicillin or certain analogs is a safe, highly predictive, nonsensitizing office procedure in the hands of physicians experienced with skin testing. It should be considered for all such individuals labeled as allergic to penicillin when they are well and not in immediate need of penicillin.

Anaphylactoid reactions to neuromuscular blocking agents: a commonly undiagnosed condition?

A group of 28 patients with extreme, life-threatening sensitivity to suxamethonium was identified and 15 were studied in detail by skin-testing. The female/male ratio was 8/1. Sensitivity may be present without previous exposure to suxamethonium; in 3 patients reactions occurred during the first exposure to anaesthesia. Most patients showed one or more cross-sensitivities to alcuronium, tubocurarine, and gallamine. Signs of circulatory collapse were the sole presenting feature in 50% of the patients. Histamine release induced by the drug in vitro was demonstrated in some instances.