Healthy
Conditions
Keywords
local skin responses, hyperemia, thermal sensation, topical warming ointments, topical cooling ointments, skin perfusion, subjective thermal sensation, muscle tissue oxygenation, skin temperature, skin redness, erythema
Brief summary
The use of topical over-the-counter (OTC) products with a warming or cooling effect is widespread in the fields of sport, physiotherapy and in private households. Advertisements for such products promise pain relief when suffering from musculoskeletal disorders such as muscle tension, rheumatism or acute injuries, e.g. sprains. In literature, there are only little information about the efficacy and the physiological mechanisms of topical warming or cooling products. Therefore, the aim of this study is to investigate the local skin characteristics during and after an application of a topical product with a warming or cooling effect.
Detailed description
The use of topical products for local pain relief in chronic or acute musculoskeletal disorders is widely used. Despite the widespread use of these products, there is missing information on the physiological mechanisms and efficacy of topical warming and cooling ointments. Most of the existing literature is about the efficacy of topical non-steroidal anti-inflammatory drug (NSAID)-products on chronic pain in osteoarthritis. Furthermore, one study tested the cooling effect of gels with different menthol concentrations. They found that, regardless of the concentration, the skin temperature was reduced up to one hour post application in the area of application. The aim of our study is to evaluate the change of skin characteristics after a single application of a warming or cooling topical product on healthy subjects. Outcome parameters include skin perfusion, temperature, skin redness and subjective thermal sensation. We only selected products in form of alcohol based ointments, menthol or wintergreen oil. Sprays and patches were excluded. The application area is the unilateral lumbar back region, whereas the contralateral side serves as control area. After an acclimatization period, baseline measurements are performed, followed by standardized application of the topical product. The local skin responses are measured in 10 mins time increments up to one hour.
Interventions
OTHERAxanova hot gel
Axanova hot gel is a topical product with a warming effect. It contains menthol, pine needle oil, wintergreen oil, rosemary oil, eucalyptus oil, incense oil.
OTHERAxanova activ gel
Axanova activ gel is a topical product with a revulsive effect. It contains menthol, pine needle oil, orange oil, lemon oil, wintergreen oil, glycosaminoglycans.
OTHERPerskindol Dolo Gel
Perskindol Dolo Gel is a topical product with a warming effect. It contains wintergreen oil, pine needle oil, aromatics, excipients.
OTHERPerskindol Classic Gel
Perskindol Classic Gel is a topical product with a revulsive effect. It contains menthol, wintergreen oil, pine needle oil, lemon oil, orange peel oil, lemon bergamot oil, rosemary oil, lavender oil, excipients.
OTHERPerskindol Cool Kühl-Gel
Perskindol Cool Kühl-Gel is a topical product with a cooling effect. It contains levomenthol, color E131, aromatics, excipients.
OTHERDolor-X Hot Gel
Dolor-X Hot Gel is a topical product with a warming effect. It contains isopropyl alcohol, water, menthol, hyprolose, camphor, trometamol, paprika, wintergreen oil, excipients.
OTHERDolor-X Classic Gel
Dolor-X Classic Gel is a revulsive product. It contains water, isopropyl alcohol, menthol, spruce, hyprolose, trometamol, wintergreen oil, excipients.
OTHERDolor-X Cool Gel
Dolor-X Cool Gel is a cooling product. It contains water, isopropyl alcohol, menthol, trometamol, color E131, excipients.
Sponsors
University of Applied Sciences and Arts of Southern Switzerland
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* no existing musculoskeletal disorders in the region of interest * no surgery in the region of interest in the last year * healthy skin conditions in the region of interest
Exclusion criteria
* fear of treatment * regular intake of drugs, excluding contraceptives * metal implants in the region between C7 and sacrum, including hip joints * lack of epicritic and protopathic skin sensitivity * renal insufficiency * bronchial asthma * pregnancy/lactation * type 1 or 2 diabetes mellitus * polyneuropathy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Local Skin Perfusion | during 45min post application | Local skin perfusion was measured with laser speckle contrast imaging (LSCI). The LSCI system uses arbitrary units to express the mean flux in the specified regions of interest which is related to the concentration of circulating erythrocytes in the tissue sample volume, scaled from blue (low perfusion) to red (high perfusion). |
| Skin Surface Temperature | At baseline and during 45 minutes post application | skin surface temperature will be measured with thermochrons, infrared thermometer and thermal imaging camera |
| Local Muscle Tissue Oxygenation | At baseline and during 45 min post application | local muscle tissue oxygenation will be measured with near infrared spectroscopy |
| Subjective Temperature Sensation | At baseline and during 45 minutes post application | Thermal sensation ("How does this feel like?") was assessed in each skin area according to the ISO 10551 standard using the following 9-point Likert scale: 4 = very hot, 3 = hot, 2 = warm, 1 = slightly warm, 0 = neutral,-1 = slightly cool,-2 = cool,-3 = cold,-4 = very cold. |
| Subjective Thermal Comfort | At baseline and during 45 minutes post application | Thermal comfort was assessed ("Do you find this. . .?") in each skin area according to the ISO 10551 standard using using a 5-point Likert scale with 0 = comfortable, 1 = slightly uncomfortable, 2 = uncomfortable, 3 = very uncomfortable, 4 = extremely uncomfortable. |
Countries
Switzerland
Contacts
PRINCIPAL_INVESTIGATORRon Clijsen, PhD
University of Applied Sciences and Arts of Southern Switzerland (SUPSI)
Participant flow
Recruitment details
A total of 21 healthy women were recruited. On each participant, two skin areas (5 cm × 10 cm) were marked on either side of the thoracic spine. Methyl salicylate gel was applied to one side, while a placebo gel was applied simultaneously to the opposite side. Thus, this was a "split-person" design, with each participant serving as her own control.
Pre-assignment details
The project originally planned to include several comparative experiments. However, due to personal and financial constraints, only one experiment was completed by the end of the study period. Owing to competing academic priorities, the study was not extended and was therefore concluded at that point.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 22.2 years STANDARD_DEVIATION 2.9 |
| Sex: Female, Male Female | 21 Participants |
| Sex: Female, Male Male | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 21 | 0 / 21 |
| other Total, other adverse events | 0 / 21 | 0 / 21 |
| serious Total, serious adverse events | 0 / 21 | 0 / 21 |
Outcome results
None listed