Biomaterial Database

Spatial and temporal profiles of flare and hyperalgesia after intradermal capsaicin. 2003

H Sumikura, and O K Andersen, and A M Drewes, and L Arendt-Nielsen

Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7, Building D3, DK-9220, Aalborg, Denmark. sumikura@smi.auc.dk

Intradermal injection of capsaicin induces a region of visual flare (neurogenic inflammation) and regions with modality specific hyperalgesia. Their temporal and spatial profiles have been studied to elucidate the mechanism behind neurogenic inflammation and hyperalgesia. Until today, the flare response has mainly been quantified by visual inspection. However, recent developments of thermography and laser-Doppler flowmetry have facilitated quantitative measurement of the neurogenic inflammation. The purpose of the present study was (1). to measure the temporal and spatial profiles of neurogenic inflammation and hyperalgesia induced by capsaicin by using thermography/laser-Doppler flowmetry and various sensory tests, and (2). to correlate the parameters related to neurogenic inflammation with the areas of secondary hyperalgesia. Eight healthy volunteers were injected intradermally with 250 microg of capsaicin. Five minutes after the injection, temperature and blood flow were measured by thermography and a laser-Doppler flowmetry, and followed by assessment of visual flare and hyperalgesia. Punctate hyperalgesia, stroking hyperalgesia, and heat hyperalgesia were assessed by von Frey hair, cotton swab, and radiant heat stimulator, respectively. This procedure was repeated 30 and 60 min after the injection. A significant increase in blood flow and temperature was detected by laser-Doppler flowmetry and thermography (F=102.08, P<0.001, and F=8.46, P=0.002, respectively). Throughout the experiment, the areas of visual flare, stroking hyperalgesia, and punctate hyperalgesia were covered by the area of significantly increased blood flow detected 5 min after the injection. The intensity of pain to heat stimuli significantly increased over time at the distal site and the proximal site (P<0.05). However, there was no significant difference between the pain intensity to radiant heat stimuli inside/outside the area of punctate hyperalgesia. These results seem to indicate that a possible contribution of neurogenic inflammation to secondary hyperalgesia (especially to radiant heat stimuli) must be reconsidered.

UI	MeSH Term	Description	Entries
D007259	Infrared Rays	That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.	Heat Waves,Heat Wave,Infrared Ray,Ray, Infrared,Rays, Infrared,Wave, Heat,Waves, Heat
D007271	Injections, Intradermal	The forcing into the skin of liquid medication, nutrient, or other fluid through a hollow needle, piercing the top skin layer.	Intradermal Injections,Injection, Intradermal,Intradermal Injection
D010147	Pain Measurement	Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.	Analgesia Tests,Analogue Pain Scale,Formalin Test,McGill Pain Questionnaire,Nociception Tests,Pain Assessment,Pain Intensity,Pain Severity,Tourniquet Pain Test,Visual Analogue Pain Scale,Analog Pain Scale,Assessment, Pain,McGill Pain Scale,Visual Analog Pain Scale,Analgesia Test,Analog Pain Scales,Analogue Pain Scales,Formalin Tests,Intensity, Pain,Measurement, Pain,Nociception Test,Pain Assessments,Pain Intensities,Pain Measurements,Pain Questionnaire, McGill,Pain Scale, Analog,Pain Scale, Analogue,Pain Scale, McGill,Pain Severities,Pain Test, Tourniquet,Questionnaire, McGill Pain,Scale, Analog Pain,Scale, Analogue Pain,Scale, McGill Pain,Severity, Pain,Test, Analgesia,Test, Formalin,Test, Nociception,Test, Tourniquet Pain,Tests, Nociception,Tourniquet Pain Tests
D010812	Physical Stimulation	Act of eliciting a response from a person or organism through physical contact.	Stimulation, Physical,Physical Stimulations,Stimulations, Physical
D012039	Regional Blood Flow	The flow of BLOOD through or around an organ or region of the body.	Blood Flow, Regional,Blood Flows, Regional,Flow, Regional Blood,Flows, Regional Blood,Regional Blood Flows
D002211	Capsaicin	An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.	8-Methyl-N-Vanillyl-6-Nonenamide,Antiphlogistine Rub A-535 Capsaicin,Axsain,Capsaicine,Capsicum Farmaya,Capsidol,Capsin,Capzasin,Gelcen,Katrum,NGX-4010,Zacin,Zostrix,8 Methyl N Vanillyl 6 Nonenamide,NGX 4010,NGX4010
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006930	Hyperalgesia	An increased sensation of pain or discomfort produced by minimally noxious stimuli due to damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve.	Hyperalgesia, Tactile,Hyperalgesia, Thermal,Hyperalgia,Hyperalgia, Mechanical,Hyperalgia, Primary,Hyperalgia, Secondary,Allodynia,Allodynia, Mechanical,Allodynia, Tactile,Allodynia, Thermal,Hyperalgesia, Mechanical,Hyperalgesia, Primary,Hyperalgesia, Secondary,Hyperalgesic Sensations,Mechanical Allodynia,Mechanical Hyperalgesia,Tactile Allodynia,Thermal Allodynia,Allodynias,Hyperalgesias,Hyperalgesias, Thermal,Hyperalgesic Sensation,Mechanical Hyperalgia,Mechanical Hyperalgias,Primary Hyperalgia,Primary Hyperalgias,Secondary Hyperalgia,Secondary Hyperalgias,Sensation, Hyperalgesic,Sensations, Hyperalgesic,Thermal Hyperalgesia
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.