Atopic dermatitis is a chronic, relapsing skin condition with no objective laboratory markers. Diagnosis relies on clinical criteria due to the lack of specific tests. The authors propose unified diagnostic guidelines to standardize diagnosis, especially for non-dermatologists. Key features include pruritus, lichenification, and a chronic course. Additional features such as xerosis, ichthyosis, elevated IgE, early onset, and a family history of atopy are also important. Minor features include cutaneous infections, non-specific hand dermatitis, nipple eczema, cheilitis, recurrent conjunctivitis, Dennie-Morgan fold, keratoconus, anterior subcapsular cataracts, orbital darkening, facial pallor/erythema, pityriasis alba, anterior neck folds, itch when sweating, wool intolerance, perifollicular accentuation, food intolerance, and environmental/emotional influences. These features help differentiate atopic dermatitis from other conditions. The term "eczema" is non-specific, and "atopic dermatitis" may be misleading due to its association with allergic conditions. The authors emphasize the importance of uniform criteria for accurate diagnosis and research. The guidelines aim to improve diagnosis and understanding of atopic dermatitis, acknowledging that clinical features may not always distinguish subgroups of patients. Future research may clarify if distinct subgroups exist.Atopic dermatitis is a chronic, relapsing skin condition with no objective laboratory markers. Diagnosis relies on clinical criteria due to the lack of specific tests. The authors propose unified diagnostic guidelines to standardize diagnosis, especially for non-dermatologists. Key features include pruritus, lichenification, and a chronic course. Additional features such as xerosis, ichthyosis, elevated IgE, early onset, and a family history of atopy are also important. Minor features include cutaneous infections, non-specific hand dermatitis, nipple eczema, cheilitis, recurrent conjunctivitis, Dennie-Morgan fold, keratoconus, anterior subcapsular cataracts, orbital darkening, facial pallor/erythema, pityriasis alba, anterior neck folds, itch when sweating, wool intolerance, perifollicular accentuation, food intolerance, and environmental/emotional influences. These features help differentiate atopic dermatitis from other conditions. The term "eczema" is non-specific, and "atopic dermatitis" may be misleading due to its association with allergic conditions. The authors emphasize the importance of uniform criteria for accurate diagnosis and research. The guidelines aim to improve diagnosis and understanding of atopic dermatitis, acknowledging that clinical features may not always distinguish subgroups of patients. Future research may clarify if distinct subgroups exist.