The Effect of Thermal Stimuli on the Response to Intradermal Capsaicin in Healthy Male Participants

Not Applicable

Completed

• Conditions: Pain; Anaesthesiology - Pain management

• Registration Number: ACTRN12613000004763
• Lead Sponsor: Professor Paul Rolan

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2013-01-03
• Last Update Posted: 13 January 2020

Recruitment & Eligibility

• Status: Completed
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

A participant will be eligible for inclusion in this study only if all of the following criteria apply:
1.Male
2.Right handed
3.Aged between 18-65 years inclusive
4.In good general health without clinically significant renal, hepatic, cardiac or other disease, as determined by the Principal Investigator
5.Agree to and be capable of signing the Informed Consent Form

Exclusion Criteria

A participant will be excluded from the study if any of the following criteria apply:
1.Significant scarring on the planned site of investigation
2.Tattoos on the planned site of investigation
3.Suffering from an active inflammatory process (e.g. acute pain, influenza, active infection, rheumatoid arthritis etc.)
4.Have had a clinically significant infection in the 4 weeks prior to study day 1
5.Suffering form an impaired immune response, e.g. HIV/AIDS sufferers, Hep B or C sufferers, organ transplant recipients or known current history of malignancy. Significance is to be determined by the investigator
6.Taking immunosuppressant drugs e.g. azathioprine, methotrexate, cyclosporine
7.Dark skin colouration that precludes flare assessment
8.Positive urine drug screen for presence of non-prescribed drugs of abuse
9.Positive breath alcohol concentration prior to study day 1 and 2
10.Recent use of opioids (e.g. morphine use within 1 week, or codeine use (<30 mg) within last 5 days)
11.Use of anxiolytics, anti-depressants and anti-epileptic medications within the previous 4 weeks
12.Clinically significant abnormalities in blood tests conducted during screening, as determined by the Principal Investigator
13.Sensory deficits at the planned quantitative sensory testing (QST) site resulting from medical conditions, such as diabetes; alcohol neuropathy; severe thyroid, liver or kidney diseases
14.Suffering from a clinically diagnosed major psychiatric disorder, such as major depression; bipolar disorder; schizophrenia; anxiety disorder and psychosis
15.History of excessive use of alcohol, defined as more than 28 units of alcohol per week
16.Known disorder of thermal pain sensitivity (e.g. Raynaud’s Phenomenon)
17.Inability to tolerate study procedures at screening familiarisation session
18.Current or history of a chronic pain condition
19.Frequent migraines, as determined by the Principal Investigator

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To compare the effect of the specialised temperature bars with standard warmth/heat on spontaneous pain, flare, allodynia and hyperalgesia responses induced by intradermal capsaicin.<br><br>Spontaneous pain will be assessed using a visual analogue scale. Flare will be assessed by tracing the area of visible flare onto clear acetate. The area around the injection where participants skin has become sensitive to light stroking (allodynia) will be assessed with a foam paintbrush. The area of skin around the injection that has become painful to probing which was not painful before (hyperalgesia) will be assessed using speciliased plastic rods (von Frey hairs) which bend at a known pressure. Participants will also be asked to rate any pain experienced during the foam paintbrush (allodynia) and von Frey (hyperalgesia) test. [Baseline (pre-capsaicin), T = 5, 15, 30, 45, 60, 90 mins post intradermal capsaicin injection]

Secondary Outcome Measures

Name	Time	Method
one[None]