OBJECTIVE: To identify CPGs on AD worldwide and assess with validated instruments if those CPGs are clear, unbiased, trustworthy and evidence based (CUTE).

METHODS: We searched MEDLINE, Embase, PubMed, Web of Science, Cochrane Library, Emcare, Epistemonikos, PsycINFO and Academic Search Premier for CPGs on AD published between 1 April 2016 and 1 April 2021. Additionally we hand searched prespecified guideline resources. Screening, data extraction and quality assessment of eligible guidelines were independently carried out by two authors. Instruments used for quality assessment were the Appraisal of Guidelines for Research and Evaluation (AGREE) II Reporting Checklist, the U.S. Institute of Medicine's (IOM) criteria of trustworthiness and Lenzer's Red Flags.

RESULTS: Forty CPGs were included, mostly from countries with a high socio-demographic index. The reported quality varied enormously. Three CPGs scored 'Excellent' on all AGREEII-domains: Columbia, the Netherlands and United Kingdom (UK; antimicrobials). Three CPGs scored 'Poor' on all domains: Poland (phototherapy), Romania and Serbia. We found no association between AGREEII-scores and a country's gross domestic product. One CPG fully met all nine IOM criteria (Malaysia) and two fully met eight (European dupilumab and UK antimicrobials). Three CPGs had no red flags: Malaysia, South Korea and UK antimicrobials. 'Applicability' and 'Rigour of development' were the lowest scoring AGREEII domains; 'Lack of external review', 'Updating procedures' and 'Rating strength of recommendations' met the least IOM criteria; and most red flags were for 'Limited or no involvement of methodological expertise' and 'No external review'. Management of conflict of interests (COI) appeared challenging. When constructs of the instruments overlapped, they showed high concordance, strengthening our conclusions.