Examining the association between pruritus and quality of life in patients with atopic dermatitis treated with crisaborole.

BACKGROUND

Pruritus is a leading cause of reduced health-related quality of life (QoL) in atopic dermatitis (AD). Crisaborole ointment is a non-steroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate AD. In identical Phase 3 studies (NCT02118766, NCT02118792), crisaborole reduced disease and pruritus severity versus vehicle.

OBJECTIVE

Quantify the relationship between pruritus and QoL using data from these studies.

METHODS

Patients aged ≥2 years were randomly assigned 2 : 1 to receive crisaborole:vehicle twice daily for 28 days. QoL was measured at baseline and day 29 using the Dermatology Life Quality Index (DLQI; patients aged ≥16 years), the Children's Dermatology Life Quality Index (CDLQI; patients aged 2-15 years) and the Dermatitis Family Impact (DFI; caregivers of patients aged 2-17 years). Pruritus was measured using the Severity of Pruritus Scale (SPS), a 4-point scale from 0 ('no itching') to 3 ('bothersome itching/scratching that disturbs sleep'), and captured morning and evening via electronic diary. Data from crisaborole and vehicle arms were pooled for this analysis. A repeated-measures longitudinal model was used to estimate relationships between pruritus (SPS) and QoL (DLQI, CDLQI and DFI in separate analyses).

RESULTS

One thousand five hundred and twenty two patients received crisaborole or vehicle. A linearity assumption for the relationship between SPS and DLQI (n = 294), CDLQI (n = 1200), and DFI (n = 1293) was appropriate. For DLQI, SPS score of 0 was associated with 'no negative effect on patient QoL'; SPS score of 1 was associated with 'small effect on patient QoL'; SPS score of 2 was associated with 'moderate effect on patient QoL'; and SPS score of 3 was associated with 'very large effect on patient QoL'. The pattern of relationships between SPS and CDLQI and DFI was similar.

CONCLUSIONS

The relationships between SPS and DLQI, CDLQI and DFI substantiate the significant link between pruritus and patient/caregiver QoL in AD.