Background and objective: Eczema and psoriasis are heterogeneous cutaneous inflammatory disorders with broad and occasionally overlapping diagnostic criteria, making it difficult to distinguish psoriasis from eczema. Despite the reality that potential biomarkers, such as CCL27, have been identified for differentiating psoriasis and eczema. The current study's goals included determining the association between CCL27 expression level and disease severity and evaluating the expression level of CCL27 as a biomarker for distinguishing psoriasis and atopic dermatitis.
Methodology: A case-control study was carried out on 100 patients (50 with psoriasis and 50 with atopic dermatitis), and 50 age- and sex-matched controls were recruited after verbal and written consent was obtained. Patients receiving local or systemic treatment or with an inflammatory skin disorder were excluded. Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the CCL27 expression level.
Results: Our study found a highly significant increase in CCL27 expression (P<0.00001) in eczema patients compared to psoriasis and healthy control groups. To detect eczema, CCL27 expression levels with a cut-off value of 5.39-fold change had a high sensitivity (91.2%) and specificity (100%). In eczema patients, CCL27 was positively correlated with disease severity using SCORing Atopic Dermatitis scores (SCORAD) (P<0.00001). On the other hand, a negative correlation between CCL27 and psoriasis severity scoring using Psoriasis Area and Severity Index (PASI).
Conclusion: We conclude that CCL27 is a sensitive biomarker in differentiating psoriasis from eczema and positively correlates with psoriasis severity. A future prospective large-scale study is recommended to support our findings.