Pain diagnostics in people with haemophilia (PwH) - Pressure pain thresholds (PPT) and influence of age and joint status.

BACKGROUND: Pain is a burden for people with haemophilia (PwH) and is often underdiagnosed. Therefore, it is crucial to develop accurate tools for pain assessment.

OBJECTIVES: Pressure Pain thresholds (PPT) are valuable in the diagnosis of pain sensitivity. The meaning and influencing factors in PwH were evaluated in this study.

PATIENTS/METHOD: We investigated PPTs in 327 PwH and 121 healthy controls to compare differences, examine the influence of age on PPT-testing, and explore correlations between PPT and numeric rating scales (NRS) scales or joint status. PPTs were measured bilaterally at haemophilia-specific joints (elbow/knee/ankle) and reference landmarks (sternum/forehead). Joint status was assessed via HJHS. NRS-scales were used to evaluate current, mean, and maximum pain over the last 4 weeks.

RESULTS: PPTs varied significantly across haemophilia-specific joints, such as knees and ankles when compared to controls (p<0.001), but showed no significant differences at the elbows (p≥0.123) or reference landmarks (p≥0.621). Age did not influence PPTs in both groups. Contrastingly, age-related effects were observed on nearly all NRS-scales (current/mean/max) in both groups. Correlations between PPTs and NRS scales were low (r≤-0.212), indicating that they measure different dimensions of pain.

CONCLUSION: This study demonstrates that PPT measurement is an important method of pain assessment in PwH. Joint-specific PPT values are independent of age and correlate with the presence of affected joints, potentially reflecting the local joint condition, while NRS scales likely represent the overall pain status. Therefore, PPT it a useful tool for pain assessment in PwH, particularly for diagnostics of joint-specific pain sensitivity.

Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.

PMID: 41197804