TY - JOUR
T1 - Experimenter- A nd infrared thermography-derived measures of capsaicin-induced neurogenic flare among non-hispanic white and black adults
AU - Fulton, Brook A.
AU - Burton, Emily F.
AU - Nance, Sabrina
AU - Letzen, Janelle E.
AU - Campbell, Claudia M.
N1 - Funding Information:
Funding sources: This study was supported by grants from the National Institutes of Health to Drs. Claudia Campbell (R01MD009063) and Janelle Letzen (F32HL143941).
Funding Information:
This study was supported by grants from the National Institutes of Health to Drs. Claudia Campbell (National Institute on Minority Health and Health Disparities; R01MD009063) and Janelle Letzen (National Heart, Lung, and Blood Institute; F32HL143941).
Publisher Copyright:
© 2020 Oxford University Press. All rights reserved.
PY - 2020
Y1 - 2020
N2 - Objective. Capsaicin is a widely utilized experimental pain stimulus; however, few studies have reported on ethnic differences in pain responses to capsaicin. The present study used infrared thermography to 1) measure differences in capsaicin-induced neurogenic flare between non-Hispanic black (NHB) and non-Hispanic white (NHW) adults and 2) determine the association between neurogenic flare and secondary hyperalgesia.Methods. Fifty-four participants (NHB N28) underwent heat/capsaicin sensitization model procedures. Neurogenic flare was examined using experimenter (i.e., subjective) and thermography (i.e., objective) measurements. A typically nonpainful mechanical punctate probe was used to measure secondary hyperalgesia.Results. Ethnic groups did not significantly differ in age, sex, marital status, or personal income. Although experimenters rated a significantly wider area of capsaicinrelated neurogenic flare among NHW compared with NHB participants (F1, 52 = 8.33, P = 0.006), thermography results showed no differences between groups in neurogenic flares (F1, 52 = 0.01, P = 0.93). Further, although NHB individuals reported greater average pain during the capsaicin procedures compared with NHW individuals (NHB=58.57 [3.67], NHW=46.46 [3.81]; F2, 51 = 5.19, P = 0.03), the groups did not differ in secondary hyperalgesia (F2, 51 = 0.03, P = 0.86), and ethnicity did not moderate the association between neurogenic flare and secondary hyperalgesia (F3, 50 = 0.24, P = 0.87).Conclusions. Findings cautiously support the use of infrared thermography over subjective experimenter report when measuring neurogenic inflammation in diverse samples. However, infrared thermography should not be used as a diagnostic tool for pain, given the lack of association between these factors. Future research is warranted to replicate these findings in a larger and more diverse sample to determine accurate neurogenic inflammation measures across other ethnic minority populations.
AB - Objective. Capsaicin is a widely utilized experimental pain stimulus; however, few studies have reported on ethnic differences in pain responses to capsaicin. The present study used infrared thermography to 1) measure differences in capsaicin-induced neurogenic flare between non-Hispanic black (NHB) and non-Hispanic white (NHW) adults and 2) determine the association between neurogenic flare and secondary hyperalgesia.Methods. Fifty-four participants (NHB N28) underwent heat/capsaicin sensitization model procedures. Neurogenic flare was examined using experimenter (i.e., subjective) and thermography (i.e., objective) measurements. A typically nonpainful mechanical punctate probe was used to measure secondary hyperalgesia.Results. Ethnic groups did not significantly differ in age, sex, marital status, or personal income. Although experimenters rated a significantly wider area of capsaicinrelated neurogenic flare among NHW compared with NHB participants (F1, 52 = 8.33, P = 0.006), thermography results showed no differences between groups in neurogenic flares (F1, 52 = 0.01, P = 0.93). Further, although NHB individuals reported greater average pain during the capsaicin procedures compared with NHW individuals (NHB=58.57 [3.67], NHW=46.46 [3.81]; F2, 51 = 5.19, P = 0.03), the groups did not differ in secondary hyperalgesia (F2, 51 = 0.03, P = 0.86), and ethnicity did not moderate the association between neurogenic flare and secondary hyperalgesia (F3, 50 = 0.24, P = 0.87).Conclusions. Findings cautiously support the use of infrared thermography over subjective experimenter report when measuring neurogenic inflammation in diverse samples. However, infrared thermography should not be used as a diagnostic tool for pain, given the lack of association between these factors. Future research is warranted to replicate these findings in a larger and more diverse sample to determine accurate neurogenic inflammation measures across other ethnic minority populations.
KW - Capsaicin
KW - Ethnic Differences
KW - Flare
KW - Objective Measurements
KW - Subjective Measurements
UR - http://www.scopus.com/inward/record.url?scp=85094933446&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85094933446&partnerID=8YFLogxK
U2 - 10.1093/PM/PNAA006
DO - 10.1093/PM/PNAA006
M3 - Article
C2 - 32142151
AN - SCOPUS:85094933446
SN - 1526-2375
VL - 21
SP - 2262
EP - 2270
JO - Pain Medicine (United States)
JF - Pain Medicine (United States)
IS - 10
ER -