Objective

Evaluation of the role of cathepsin S in pruritus associated with seborrheic dermatitis.

Cathepsin S is a cysteine protease that activates PAR-2 (proteinase-activated receptor 2) receptors

Methodology

N= 11 adult patients with seborrheic dermatitis of the scalp, compared with a control group (n=10)

Assessment of PAR2 and histamine protein expression to compare the results of two distinct pruritus-inducing pathways

Evaluation criteria

Global clinical score for severity of seborrheic dermatitis scored by the investigator (Squire score from 0 to 80)

Intensity of pruritus scored by patients (4-point scale)

Results

• Cathepsin S levels in patients with seborrheic dermatitis 5 times higher than in the control group 
• Positive correlation between cathepsin S levels, PAR-2 receptor expression and pruritus intensity

Conclusion

Cathepsin S can be used as a biomarker to quantify pruritus sensations and contribute to the quantitative evaluation of the efficacy of seborrheic dermatitis treatments