Prospective, multicenter clinical trial to validate new products for skin tests in the diagnosis of allergy to penicillin.
BACKGROUND
Allergy to penicillin is the most commonly reported type of drug hypersensitivity. Diagnosis is currently confirmed using skin tests with benzylpenicillin reagents, ie, penicilloyl-polylysine (PPL) as the major determinant of benzylpenicillin and benzylpenicillin, benzylpenicilloate and benzylpenilloate as a minor determinant mixture (MDM).


OBJECTIVE
To synthesize and assess the diagnostic capacity of 2 new benzylpenicillin reagents in patients with immediate hypersensitivity reactions to B-lactams: benzylpenicilloyl octa-L-lysine (BP-OL) as the major determinant and benzylpenilloate (penilloate) as the minor determinant.


METHODS
Prospective multicenter clinical trial performed in 18 Spanish centers. Efficacy was assessed by detection of positive skin test results in an allergic population and negative skin test results in a nonallergic, drug-exposed population. Sensitivity, specificity, and negative and positive predictive values were determined.


RESULTS
The study sample comprised 94 allergic patients: 31 (35.23%) presented anaphylaxis, 4 (4.55%) anaphylactic shock, 51 (58.04%) urticaria, and 2 (2.27%) no specific condition. The culprit 8-lactams were amoxicillin in 63 cases (71.60%), benzypencillin in 14 cases (15.89%), cephalosporins in 2 cases (2.27%), other drugs in 3 cases (3.42%), and unidentified agents in 6 cases (6.82%). The results of testing with BP-OL were positive in 46 cases (52.3%); the results of testing with penilloate were positive in 33 cases (37.5%). When both reagents were taken into consideration, sensitivity reached 61.36% and specificity 100%. Skin testing with penilloate was significantly more often negative when the interval between the reaction and the study was longer.


CONCLUSIONS
The sensitivity of BP-OL and penilloate was 61%. Considering that amoxicillin was the culprit drug in 71% of reactions, these results indicate that most patients were allergic to the whole group of penicillins. These data support the use of benzylpenicillin determinants in the diagnosis of allergy to beta-lactams, even in predominantly amoxicillin-allergic populations.
Allergy Section, General University Hospital, UMH, Alicante, Spain fj.fernandez@umh.es
J
J
Fernández
Allergy Service, Carlos Haya Hospital, Málaga, Spain
M J
MJ
Torres
Research Unit, Diater laboratory, Madrid, Spain
J
J
Campos
Research Unit, Diater laboratory, Madrid, Spain
F
F
Arribas-Poves
Allergy Service, Carlos Haya Hospital, Málaga, Spain
M
M
Blanca
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000276:immunology; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010400:Penicillin G / Q000031:analogs & derivatives*; D010406:Penicillins / Q000009:adverse effects* / Q000276:immunology; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000379:methods*; D055815:Young Adult
D000900:Anti-Bacterial Agents; D010406:Penicillins; C017609:penilloic acid; D010400:Penicillin G