Burden of skin pain in atopic dermatitis

Abstract

Background: Atopic dermatitis (AD) is associated with itch, skin inflammation and barrier disruption, and scratching, all of which may be associated with skin pain.

Objective: To characterize the patient burden of skin pain in AD.

Methods: We performed a prospective dermatology practice-based study using questionnaires and evaluation by a dermatologist.

Results: Overall, 305 patients (age range, 13-97 years) were included in the study, with 564 encounters. The cohort included 195 females (63.9%) and 193 whites (63.7%). The mean (SD) age at enrollment was 42.3 (18.1) years, and the mean (SD) age of patient-reported AD onset was 29.6 (31.9) years. At baseline, 144 patients (42.7%) reported skin pain in the past week, with 42 (13.8%) reporting severe or very severe pain. Twenty-four (16.8%) thought the skin pain was part of their itch, 16 (11.2%) from scratching, and 77 (72.0%) from both. Patients with skin pain were more likely to describe their itch using terms that resembled neuropathic pain. Prevalence of skin pain was increased in patients with vs without excoriations (72.6% vs 57.6%; χ² test P = .02) but not other morphologic characteristics. Skin pain severity was most strongly correlated with the Patient-Oriented Eczema Measure (Spearman ρ = 0.54), followed by ItchyQOL (ρ = 0.52), 5-dimensions of itch scale (ρ = 0.47), Dermatology Life Quality Index (ρ = 0.45), numeric rating scale for itch (ρ = 0.43) and sleep (ρ = 0.36), Patient Health Questionnaire 9 (ρ = 0.36), patient-reported global AD severity (ρ = 0.34), Eczema Area and Severity Index (ρ = 0.23), and objective Scoring AD index (ρ = 0.20) (P < .001 for all). Patients with both severe itch and pain vs those with only one or neither symptom being severe had significant increases in all these measures.

Conclusion: Skin pain is a common and burdensome symptom in AD. Skin pain severity should be assessed with itch severity in AD patients and may be an important end point for monitoring treatment response.

Figure 1. Pain-like descriptors of itch in atopic dermatitis

Proportion of atopic dermatitis patients who described their itch using pain-like descriptors. Results are stratified by those with vs. without skin pain. Sensitivity analyses were performed in patients reporting skin pain, who did had either no or only mild excoriations on physical exam.

Figure 2. Associations of skin pain severity with itch, atopic dermatitis signs and symptoms and quality of life

Box-whisker plots and overlaid jitter plots of (A) NRS-itch, (B) POEM, (C) mean ItchyQOL, (D) DLQI, (E) 5-D itch, (F) NRS-sleep, (G) PHQ9, (H) EASI and (I) oSCORAD.