{
    "abstract": "Patients with non-immediate hypersensitivity to beta-lactam antibiotics (\u03b2L) often avoid all \u03b2L, with limitations for future therapy.\nAssess cross-reactivity between \u03b2L in non-immediate cutaneous adverse drug reactions (ni-CADRs).\nRetrospective analysis (2000-2022) of patients with suspected ni-CADR with \u03b2L as a possible culprit who underwent patch testing (PT) with an extended antibiotic series (10% pet., Chemotechnique Diagnostics or prepared in-house) according to European Society of Contact Dermatitis (ESCD) recommendations. Fisher exact test was used with a significance of 0.05 corrected for multiple testing; positive associations were quantified with odds ratio (OR) with 95% confidence interval (CI).\nFour hundred and fourteen patients (270 female/144 male; age 52\u2009\u00b1\u200919\u2009years) were included, mostly with maculopapular exanthema (367; 89%), drug reaction with eosinophilia and systemic symptoms (DRESS) (22; 5%) and acute generalised exanthematous pustulosis (AGEP) (12; 3%). Eighty-six patients (21%) had positive results to at least one drug. Fifty-eight patients (14%) had 110 positive results to \u03b2L, mostly amoxicillin (33). Co-reactivity within penicillins was almost universal, including piperacillin with other penicillins (p\u2009=\u20090.007; OR 25; CI 3-56). There was co-reactivity to aminopenicillins and aminocephalosporins (p\u2009=\u20090.006; OR 33; CI 4-74) and within the cephalosporin subclass, including between aminocephalosporins and non-aminocephalosporins. Within carbapenems, 1 patient reacted to meropenem and ertapenem, with no extension to imipenem, as confirmed with a provocation test. Two patients reacted both to ceftriaxone and meropenem (p\u2009=\u20090.013; OR: 68; CI:15-612).\nPT is useful to confirm a probable culprit in ni-CADR to \u03b2L. Co-reactivity, interpreted mostly as cross-reactivity, occurred within cephalosporin and, particularly, with penicillin subclasses, including between piperacillin-tazobactam and remaining penicillins, which has seldom been described. There was no association between penicillins and cephalosporins as a whole, except between aminopenicillins and aminocephalosporins, attributable to a similar lateral chain amino group. We found an unexpected association between meropenem and ceftriaxone, probably a concomitant sensitization.",
    "authors": [
        {
            "affiliation": "Dermatology, University Hospital, Coimbra Local Health Unit, Coimbra, Portugal.\nFaculty of Medicine, University of Coimbra, Coimbra, Portugal.",
            "firstname": "Jo\u00e3o Nuno Barbosa",
            "initials": "JNB",
            "lastname": "Soares"
        },
        {
            "affiliation": "Dermatology, University Hospital, Coimbra Local Health Unit, Coimbra, Portugal.",
            "firstname": "Andr\u00e9 Apar\u00edcio",
            "initials": "AA",
            "lastname": "Martins"
        },
        {
            "affiliation": "Dermatology, University Hospital, Coimbra Local Health Unit, Coimbra, Portugal.",
            "firstname": "Ana Carolina",
            "initials": "AC",
            "lastname": "Figueiredo"
        },
        {
            "affiliation": "Dermatology, University Hospital, Coimbra Local Health Unit, Coimbra, Portugal.\nFaculty of Medicine, University of Coimbra, Coimbra, Portugal.",
            "firstname": "Andr\u00e9 Castro",
            "initials": "AC",
            "lastname": "Pinho"
        },
        {
            "affiliation": "Faculty of Medicine, University of Coimbra, Coimbra, Portugal.",
            "firstname": "Francisco",
            "initials": "F",
            "lastname": "Caramelo"
        },
        {
            "affiliation": "Dermatology, University Hospital, Coimbra Local Health Unit, Coimbra, Portugal.\nFaculty of Medicine, University of Coimbra, Coimbra, Portugal.",
            "firstname": "Margarida",
            "initials": "M",
            "lastname": "Gon\u00e7alo"
        }
    ],
    "conclusions": "PT is useful to confirm a probable culprit in ni-CADR to \u03b2L. Co-reactivity, interpreted mostly as cross-reactivity, occurred within cephalosporin and, particularly, with penicillin subclasses, including between piperacillin-tazobactam and remaining penicillins, which has seldom been described. There was no association between penicillins and cephalosporins as a whole, except between aminopenicillins and aminocephalosporins, attributable to a similar lateral chain amino group. We found an unexpected association between meropenem and ceftriaxone, probably a concomitant sensitization.",
    "copyrights": "\u00a9 2025 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.",
    "doi": "10.1111/cod.14767",
    "journal": "Contact dermatitis",
    "keywords": [
        "DRESS",
        "antibiotics",
        "beta\u2010lactam",
        "carbapenem",
        "cephalosporin",
        "cross\u2010reactivity",
        "cutaneous adverse drug reaction",
        "non\u2010immediate",
        "patch testing",
        "penicillin"
    ],
    "methods": null,
    "publication_date": "2025-03-17",
    "pubmed_id": "40090865",
    "results": "Four hundred and fourteen patients (270 female/144 male; age 52\u2009\u00b1\u200919\u2009years) were included, mostly with maculopapular exanthema (367; 89%), drug reaction with eosinophilia and systemic symptoms (DRESS) (22; 5%) and acute generalised exanthematous pustulosis (AGEP) (12; 3%). Eighty-six patients (21%) had positive results to at least one drug. Fifty-eight patients (14%) had 110 positive results to \u03b2L, mostly amoxicillin (33). Co-reactivity within penicillins was almost universal, including piperacillin with other penicillins (p\u2009=\u20090.007; OR 25; CI 3-56). There was co-reactivity to aminopenicillins and aminocephalosporins (p\u2009=\u20090.006; OR 33; CI 4-74) and within the cephalosporin subclass, including between aminocephalosporins and non-aminocephalosporins. Within carbapenems, 1 patient reacted to meropenem and ertapenem, with no extension to imipenem, as confirmed with a provocation test. Two patients reacted both to ceftriaxone and meropenem (p\u2009=\u20090.013; OR: 68; CI:15-612).",
    "title": "Decoding Beta-Lactam Cross-Reactivity - Longitudinal Patch Testing From 2000 to 2022.",
    "xml": "<Element 'PubmedArticle' at 0x788504539170>"
}