Psoriasis in difficult to treat areas: treatment role in improving health-related quality of life and perception of the disease stigma.

Background: When psoriasis affects scalp, nails, palms and soles, it is considered difficult to treat and causes severe impairment of life quality.

Objective: We evaluated which difficult site most impacts on the patient's quality of life and how quality of life changes during treatment.

Methods: We conducted a prospective observational study in patients receiving adalimumab over a 24 weeks period, through assessment at weeks 0, 4 and 24 using PASI, PAIN VAS, ITCH VAS, DLQI, NAPSI, PSSI. Pearson correlation was used to evaluate the relationship between the various measurements on the basis of three different deltas (between T0 and T24, between T0 and T4, between T0 and average between T4 and T24).

Results: The correlation matrix between T0 and T24 shows a significant correlation between delta PASI and delta ITCH and delta ITCH and delta DLQI and a significant correlation between ITCH delta and DLQI delta and a correlation close to significance between DLQI and NAPSI.

Conclusion: We identified itching as a mediator between the cutaneous extension of psoriasis and the impact on quality of life. We also documented the predominant role of nail psoriasis in defining the impact on the quality of life of the psoriatic patient.