Neuropathic pain in patients with sickle cell disease

BACKGROUND: Despite the suggestion of a neuropathic component to sickle cell disease (SCD) pain, there are minimal data on the systematic assessment of neuropathic pain in patients with SCD. Neuropathic pain is defined as pain primarily initiated by dysfunction of the peripheral or central nervous system. PROCEDURE: In a cross-sectional study, we used the painDETECT questionnaire, a one-page validated neuropathic pain screening tool, to determine the presence of neuropathic pain in patients with SCD and to evaluate the relationship between neuropathic pain, age, and gender. We hypothesized that 20% of patients with SCD will experience neuropathic pain and that neuropathic pain will be associated with older age and female gender. The completed painDETECT questionnaire yields a total score between 0 and 38 (≥ 19 = definite neuropathic pain, 13-18 = probable neuropathic pain, ≤ 12 = no neuropathic pain). Scores ≥ 13 were designated as having evidence of neuropathic pain. RESULTS: A total of 56 patients participated. Median age was 20.3 years and 77% were female. We found 37% of patients had evidence of neuropathic pain. Age was positively correlated with total score (r = 0.43; P = 0.001) suggesting older patients experience more neuropathic pain. Females had higher mean total scores (13 vs. 8.4; P = 0.04). Significantly more patients with neuropathic pain were taking hydroxyurea (90% vs. 59%; P = 0.015). Despite 37% of patients experiencing neuropathic pain, only 5% were taking a neuropathic pain drug. CONCLUSIONS: Neuropathic pain exists in SCD. Valid screening tools can identify patients that would benefit from existing and future neuropathic pain therapies and could determine the impact of these therapies.