Skin and patch tests of Italian cases
On the first day, prick and intradermal tests with immediate and delayed
reading were carried out using penicilloyl-polylysine, minor determinant
mixture , and benzylpenicillin as described
previously.16 Patch tests were administered with
benzylpenicillin, ampicillin, amoxicillin, cephalexin, cefaclor, and
cefadroxil in petrolatum as described.17 All reagents
of patch testing were applied to uninvolved skin on the interscapular
region of the patient’s back, using acrylate adhesive strips with small
plates attached for test allergens (Curatest, Lohmann GmbH & Co. KG,
Neuwied, Germany), as previously described.17Occlusion time was 48 hours. Readings of patch tests were made 15
minutes after removal of the strips and 48 hours later. Positive
reactions were scored as: + (erythema, infiltration, possibly discrete
papules); ++ (erythema, infiltration, papules, and vesicles); and +++
(intense erythema, infiltration, and coalescing vesicles). Participants
who had negative results in the allergy tests with the alternative
cephalosporins concerned underwent controlled administrations of
therapeutic doses of ceftriaxone (1 g), intramuscularly, as well as
cefuroxime axetil (500 mg), cephalexin (1 g), cefaclor (500 mg), and
cefadroxil (500 mg), orally, each in a different day and in the above
order, as previously described.16 In case of a
positive response to an aminocephalosporin, the others were not
administered. Patients were carefully monitored during all allergy
testing, and for six hours after challenges. They were also asked to
return to the clinical department to show any positive responses.