title: Non-immediate Cutaneous Reactions to Beta-Lactams: Approach to Diagnosis.
abstract: Non-immediate cutaneous reactions (i.e., occurring at least 1 h after the initial drug administration), particularly maculopapular exanthemas and urticarial eruptions, are common during beta-lactam treatments. A T cell-mediated pathogenic mechanism has been demonstrated in some cutaneous reactions, such as maculopapular exanthema, fixed drug eruption, acute generalized exanthematous pustulosis, and drug-induced hypersensitivity syndrome. In the diagnostic work-up, patch testing is useful, together with delayed-reading intradermal testing. Patch tests are a simple and safe diagnostic tool, which in the case of severe reactions should be used as the first line of investigation. However, patch tests are less sensitive than intradermal tests, which are preferable in subjects with mild reactions. Lymphocyte transformation or activation tests and enzyme-linked immunosorbent spot assays can be used as complementary tests. In selected cases of mild or moderate reactions, displaying negative results in the aforesaid allergy tests, a graded challenge with the implicated beta-lactam can be performed.
authors.affiliation: Allergy Unit, Presidio Columbus, Via G. Moscati, 31, 00168, Rome, Italy. aromano.allergy@gmail.com.|IRCCS Oasi Maria S.S, Troina, Italy. aromano.allergy@gmail.com.
authors.forename: Antonino
authors.initials: A
authors.lastname: Romano
authors.affiliation: Allergy Unit, Presidio Columbus, Via G. Moscati, 31, 00168, Rome, Italy.|Department of Pediatrics, Division of Allergy, Pediatric Hospital Bambino Gesù, Rome, Vatican City, Italy.
authors.forename: Rocco Luigi
authors.initials: RL
authors.lastname: Valluzzi
authors.affiliation: Allergy Unit, Presidio Columbus, Via G. Moscati, 31, 00168, Rome, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Caruso
authors.affiliation: Allergy Unit, Presidio Columbus, Via G. Moscati, 31, 00168, Rome, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Maggioletti
authors.affiliation: Allergy Unit, Presidio Columbus, Via G. Moscati, 31, 00168, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Gaeta
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000175:diagnosis*; D007428:Intradermal Tests; D008213:Lymphocyte Activation; D000069342:Medical Overuse; D012882:Skin Tests / Q000379:methods*; D014581:Urticaria / Q000175:diagnosis; D047090:beta-Lactams / Q000009:adverse effects*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams
keywords: Beta-lactam allergy; Challenges; Cross-reactivity; Non-immediate reactions; Skin tests; Tolerability