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Utility of major and minor determinants in the diagnosis of penicillin allergy
S268 Abstracts
1"The Value of Routine Penicillin Skin Testing in an Outpatient Jr Population Richard J Warrington, E/lie Linda Tsai University of Manitoba, Winnipeg, MB, Canada When to skin test a patient who has a history of penicillin allergy is controversial. In Canada, it is common to carry out routine skin testing of these patients instead of waiting until the need for using penicillin arises. Patients who are penicillin skin test negative are advised that they may take penicillins in the future, if indicated. The purpose of this study is to ascertain the value and risks of routine penicillin skin testing in an outpatient population, by determining how many patients actually take penicillins after being skin test negative, and if there were any adverse reactions. Patients from an outpatient allergy clinic were enrolled in the study if they had a positive history for penicillin allergy, but were negative to epicutaneous and intradermal testing to the major and minor determinants of penicillin, as confirmed by chart review. There were 2 patient populations evaluated: One group between 1983-1986 who were given a survey to return, and a second group between 1993-1997 who had a standardized telephone questionnaire. Because the results of the 2 groups analyzed separately were similar, the data was pooled. In total, 185 patients were assessed, but 77 were lost to follow up, mainly because the patients had moved, leaving 108 evaluable patients. Of these, 64 had required antibiotics after being penicillin skin test negative in clinic. Only 48% (31 patients) took penicillins, of whom 4 had adverse events (2 developed a rash to amoxicillin, and 2 had diarrhea). The remaining 33 patients received alternative antibiotics. In the 1993-1997 group of patients, 6/19 patients who took alternative antibiotics avoided penicillin on the advice of their family physician. The rest did so because either they were afraid/reluctant to take penicillin especially in the face of many good alternatives, or their allergist advised them to avoid penicillin unless they had a serious infection. In conclusion, despite negative penicillin skin tests only 48% of patients who subsequently required antibiotics took penicillins. Therefore, it may be more cost effective, but less practical, to penicillin skin test only those patients in whom penicillin therapy is necessary, or in those who would agree to take it if the skin test were negative. Of the patients who did subsequently take penicillins, no one had a serious immediate type allergic reaction. These results are consistent with a similar previously reported study conducted with inpatients. (Allergy Asthma Proc.21 (5):297)
gl
g Utility of Major and Minor Determinants in the Diagnosis of
U g g,JI Penicillin Allergy
PA Greenberger Northwestern University Medical School Chicago, ]L PURPOSE: To define the utility of penicillin major and minor determinants in patients with a history of penicillin allergy. M E T H O D S : A prospective series from 1984-2001 of 648 patients who underwent skin testing with the major determinant (Pre-Pen) and 3 minor determinants was analyzed. The history was convincing, unknown or equivocal. Minor determinants were used initially at 10-2M (Na benzylpenicilloate, benzylpenicilloyl-n-propylamine) and K PCN G (6000 units/ml). They were stored lyophilized until reconstituted before use. A wheal of 4 m with erythema was considered positive with negative control and positive histamine. Indeterminate skin tests occurred if there was a wheal without erythema or if the histamine was negative. RESULTS: Skin tests were positive in 73/648 (11.3%). None of 11 patients who received penicillins (n=4) or cephalosporins (n=7) by challenge had an untoward reaction. The history of penicillin allergy was convincing (urticaria, etc) in 51 (69.9%), equivocal (rash or injection site reaction) in 15 (20.5%) and unknown in 7 (9.6%). Skin tests were positive to Pre-Pen alone in 44 (60.3%), Pre-Pen and at least 1 minor determinant in 11 (15.1%), K PCN G in 4, Na benzylpenicilloate in 4, benzylpenicilloyl-p-
J ALLERGYCLIN IMMUNOL JANUARY2002 propylamine in 4 and all 4 reagents in 4. Two patients reacted to all 3 minor determinants but not PrePen. CONCLUSIONS: 1) The majority (69.9%) of patients who were skin test positive had convincing histories. 2) Overall, 11.3% of penicillin allergic patients had positive skin tests. 3) If Pre-Pen were not used, but 3 minor determinants were, 60% of skin test positive patients would have been missed.
1 (~ Safety of Cephalosporin Administration to Patients With Histog mJPries of Penicillin Allergy Sonak B Daulat, Roland Solensk), Harry Earl, Rebecca Gruchalla University of Texas Southwestern, Dallas, TX There is still no consensus about whether or not it is safe to administer cephalosporins to patients with histories of penicillin allergy. Cephalosporins and penicillins both share a common beta-lactam ring and, for this reason, there is a potential for cross-reactivity. Currently it is recommended that all patients who have a history of penicillin allergy should undergo penicillin skin testing prior to receiving a cephalosporin. In this study, we chose to determine the cephalosporin reaction rate in hospitalized patients who reported a history of penicillin allergy upon admission and who were given a cephalosporin. Patient data was compiled over approximately two years (August 1999 - June 2001) and a total of 606 patients were identified through hospital pharmacy records. These patients received 685 cephalosporin courses during this time period. Of the 685 courses, 42% were first generation, 21% were second generation, and 37% were either third or fourth generation cephalosporins. We asked the medical records department to query their database over the same time period for all adverse drug reactions to cephalosporins that had been recorded by the inpatient medical coders. These in-house reactions are labeled as "E-codes" based on the international classification system found in the ICD-9 codebook. Based on this data, there were 16 recorded E-codes to cephalosporins during the time period. When we matched these 16 patients with the 606 patients who had a history of penicillin allergy and received a cephalosporin, only one patient was in both groups. In reviewing that chart, the patient was noted to have had mild worsening of her underlying eczema after the administration of cefazolin. Random chart reviews were performed to confirm the information we had received through medical records. In reviewing 20 of the 606 charts, we too found no occurrence of an adverse drug reaction in the penicillin-allergy-history-positive patients who had received a cephalosporin. Charts from 10 patients who had been labeled as having a cephalosporin-induced reaction were also reviewed and found to be correctly labeled. In our hospital, patients who give a history of penicillin allergy are frequently given a cephalosporin without prior penicillin skin testing. We found that 605 out of 606 patients evaluated who had penicillin allergy histories and who were administered a cephalosporin tolerated that cephalosporin without adverse event. It is important to note, however, that for those patients who relay a severe penicillin allergy history, such as anaphylaxis, the in-patient pharmacists typically recommend that cephalosporins not be administered without further evaluation. In summary, our data suggest that patients with non-life threatening histories of penicillin allergy can safely tolerate cephalosporins.
a'~
Nasal Provocation Test With Lysine-Acetylsalicylate in the
8 u - - V Diagnosis of NSAIDs Intolerance With Respiratory Symptoms
Ruperto Gonzdlez-Prrez, Ramon Vives, Paloma Poza-Guedes, Rosa Merchrn, Stefan Cimbollek, Julia Rodriguez Hospital Doce de Octubre, Madrid, Spain BACKGROUND: The diagnosis of NSAID intolerance (NI) relies on clinical history and oral provocation test (OPT). Both bronchial (BPT) and nasal (NPT) provocation test with lysine-acetylsalicylate (L-ASA) are considered alternative methods in the diagnosis of NI, but further investiga-
1"The Value of Routine Penicillin Skin Testing in an Outpatient Jr Population Richard J Warrington, E/lie Linda Tsai University of Manitoba, Winnipeg, MB, Canada When to skin test a patient who has a history of penicillin allergy is controversial. In Canada, it is common to carry out routine skin testing of these patients instead of waiting until the need for using penicillin arises. Patients who are penicillin skin test negative are advised that they may take penicillins in the future, if indicated. The purpose of this study is to ascertain the value and risks of routine penicillin skin testing in an outpatient population, by determining how many patients actually take penicillins after being skin test negative, and if there were any adverse reactions. Patients from an outpatient allergy clinic were enrolled in the study if they had a positive history for penicillin allergy, but were negative to epicutaneous and intradermal testing to the major and minor determinants of penicillin, as confirmed by chart review. There were 2 patient populations evaluated: One group between 1983-1986 who were given a survey to return, and a second group between 1993-1997 who had a standardized telephone questionnaire. Because the results of the 2 groups analyzed separately were similar, the data was pooled. In total, 185 patients were assessed, but 77 were lost to follow up, mainly because the patients had moved, leaving 108 evaluable patients. Of these, 64 had required antibiotics after being penicillin skin test negative in clinic. Only 48% (31 patients) took penicillins, of whom 4 had adverse events (2 developed a rash to amoxicillin, and 2 had diarrhea). The remaining 33 patients received alternative antibiotics. In the 1993-1997 group of patients, 6/19 patients who took alternative antibiotics avoided penicillin on the advice of their family physician. The rest did so because either they were afraid/reluctant to take penicillin especially in the face of many good alternatives, or their allergist advised them to avoid penicillin unless they had a serious infection. In conclusion, despite negative penicillin skin tests only 48% of patients who subsequently required antibiotics took penicillins. Therefore, it may be more cost effective, but less practical, to penicillin skin test only those patients in whom penicillin therapy is necessary, or in those who would agree to take it if the skin test were negative. Of the patients who did subsequently take penicillins, no one had a serious immediate type allergic reaction. These results are consistent with a similar previously reported study conducted with inpatients. (Allergy Asthma Proc.21 (5):297)
gl
g Utility of Major and Minor Determinants in the Diagnosis of
U g g,JI Penicillin Allergy
PA Greenberger Northwestern University Medical School Chicago, ]L PURPOSE: To define the utility of penicillin major and minor determinants in patients with a history of penicillin allergy. M E T H O D S : A prospective series from 1984-2001 of 648 patients who underwent skin testing with the major determinant (Pre-Pen) and 3 minor determinants was analyzed. The history was convincing, unknown or equivocal. Minor determinants were used initially at 10-2M (Na benzylpenicilloate, benzylpenicilloyl-n-propylamine) and K PCN G (6000 units/ml). They were stored lyophilized until reconstituted before use. A wheal of 4 m with erythema was considered positive with negative control and positive histamine. Indeterminate skin tests occurred if there was a wheal without erythema or if the histamine was negative. RESULTS: Skin tests were positive in 73/648 (11.3%). None of 11 patients who received penicillins (n=4) or cephalosporins (n=7) by challenge had an untoward reaction. The history of penicillin allergy was convincing (urticaria, etc) in 51 (69.9%), equivocal (rash or injection site reaction) in 15 (20.5%) and unknown in 7 (9.6%). Skin tests were positive to Pre-Pen alone in 44 (60.3%), Pre-Pen and at least 1 minor determinant in 11 (15.1%), K PCN G in 4, Na benzylpenicilloate in 4, benzylpenicilloyl-p-
J ALLERGYCLIN IMMUNOL JANUARY2002 propylamine in 4 and all 4 reagents in 4. Two patients reacted to all 3 minor determinants but not PrePen. CONCLUSIONS: 1) The majority (69.9%) of patients who were skin test positive had convincing histories. 2) Overall, 11.3% of penicillin allergic patients had positive skin tests. 3) If Pre-Pen were not used, but 3 minor determinants were, 60% of skin test positive patients would have been missed.
1 (~ Safety of Cephalosporin Administration to Patients With Histog mJPries of Penicillin Allergy Sonak B Daulat, Roland Solensk), Harry Earl, Rebecca Gruchalla University of Texas Southwestern, Dallas, TX There is still no consensus about whether or not it is safe to administer cephalosporins to patients with histories of penicillin allergy. Cephalosporins and penicillins both share a common beta-lactam ring and, for this reason, there is a potential for cross-reactivity. Currently it is recommended that all patients who have a history of penicillin allergy should undergo penicillin skin testing prior to receiving a cephalosporin. In this study, we chose to determine the cephalosporin reaction rate in hospitalized patients who reported a history of penicillin allergy upon admission and who were given a cephalosporin. Patient data was compiled over approximately two years (August 1999 - June 2001) and a total of 606 patients were identified through hospital pharmacy records. These patients received 685 cephalosporin courses during this time period. Of the 685 courses, 42% were first generation, 21% were second generation, and 37% were either third or fourth generation cephalosporins. We asked the medical records department to query their database over the same time period for all adverse drug reactions to cephalosporins that had been recorded by the inpatient medical coders. These in-house reactions are labeled as "E-codes" based on the international classification system found in the ICD-9 codebook. Based on this data, there were 16 recorded E-codes to cephalosporins during the time period. When we matched these 16 patients with the 606 patients who had a history of penicillin allergy and received a cephalosporin, only one patient was in both groups. In reviewing that chart, the patient was noted to have had mild worsening of her underlying eczema after the administration of cefazolin. Random chart reviews were performed to confirm the information we had received through medical records. In reviewing 20 of the 606 charts, we too found no occurrence of an adverse drug reaction in the penicillin-allergy-history-positive patients who had received a cephalosporin. Charts from 10 patients who had been labeled as having a cephalosporin-induced reaction were also reviewed and found to be correctly labeled. In our hospital, patients who give a history of penicillin allergy are frequently given a cephalosporin without prior penicillin skin testing. We found that 605 out of 606 patients evaluated who had penicillin allergy histories and who were administered a cephalosporin tolerated that cephalosporin without adverse event. It is important to note, however, that for those patients who relay a severe penicillin allergy history, such as anaphylaxis, the in-patient pharmacists typically recommend that cephalosporins not be administered without further evaluation. In summary, our data suggest that patients with non-life threatening histories of penicillin allergy can safely tolerate cephalosporins.
a'~
Nasal Provocation Test With Lysine-Acetylsalicylate in the
8 u - - V Diagnosis of NSAIDs Intolerance With Respiratory Symptoms
Ruperto Gonzdlez-Prrez, Ramon Vives, Paloma Poza-Guedes, Rosa Merchrn, Stefan Cimbollek, Julia Rodriguez Hospital Doce de Octubre, Madrid, Spain BACKGROUND: The diagnosis of NSAID intolerance (NI) relies on clinical history and oral provocation test (OPT). Both bronchial (BPT) and nasal (NPT) provocation test with lysine-acetylsalicylate (L-ASA) are considered alternative methods in the diagnosis of NI, but further investiga-