Patch testing with semisynthetic penicillins

Repeated patch testing in delayed hypersensitivity to beta‐Iactam antibiotics

“…The fact that none of these patients had become negative and that, in over 1/2 the cases, repeat testing was performed 3 years or more after the initial test, suggests that delayed hypersensitivity to BLs is a long-lasting condition, although reactivity may fluctuate, as observed by Meller & Jeppesen (2). It is possible that the 2 new cases of penicillin sensitivity were induced by the initial patch tests with this drug; both patients denied use of penicillin in the interval between tests.…”

“…In 15 patients with such rashes, patch tests repeated up to 100 weeks after the clinical reaction revealed that 3 had become negative (1). However, a study of occupational allergies to semisynthetic penicillins has shown that these allergies do not disappear over time, though the degree of reactivity may fluctuate (2).…”

Long‐term reproducibility of positive patch test reactions in patients with non‐immediate cutaneous adverse drug reactions to antibiotics

“…In patients with contact dermatitis, the long-term reproducibility of positive patch test reactions may vary from 66% to 71%, and does not seem to be affected by the time elapsed between tests (9,11). In patients with occupational contact dermatitis caused by penicillins, it was shown that patch test reactivity did not disappear over time, although the intensity could fluctuate (12). Nevertheless, in the setting of NI CADRs to antibiotics, patch tests have rarely been repeated for assessment of the long-term reproducibility of initially positive results.…”

Changes in penicillin contamination and allergy in factory workers

“…Methods 56 workers developed allergy shortly after exposure to pivampicillin, the majority within a period of 3 months. 50 developed eczema on the face and arms, and the allergy was verified by patch testing (1)(2)(3). 31 developed hay fever and II asthma.…”