The Effect of Gua Sha Treatment on the Microcirculation of Surface Tissue: A Pilot Study in Healthy Subjects

Context

Gua Sha, therapeutic surface frictioning that intentionally raises transitory petechiae and ecchymosis, is a traditional East Asian healing technique also known as cao gio, coining, scraping, and spooning. There are case reports in Western literature but no studies on the physiological effects of Gua Sha.

Objective

To study the microcirculatory effects of Gua Sha on the skin and subcutis in humans to elucidate physiological mechanisms responsible for the clinically observed pain-relieving effect of this treatment

Design

Laser Doppler imaging (LDI) was used to make sequential measurements of the microcirculation of surface tissue before and after Gua Sha treatment in 11 healthy subjects. The effect of Gua Sha treatment on the microcirculation of surface tissue was expressed as changes from baseline in arbitrary perfusion units (PU).

Setting

The study was conducted at the Department of Nephrology, Unit of Circulation Research, University Hospital of Essen, Germany.

Subjects

Subjects were volunteers from the nursing and physician staff of the Kliniken Essen.

Intervention

A single Gua Sha treatment was applied to an area of each subject’s back.

Outcome Measures

Change in microcirculation was measured in PUs. Change in myalgia was subjectively reported and confirmed by manual palpation.

Results

Gua Sha caused a fourfold increase in microcirculation PUs at the treated area for the first 7.5 minutes following treatment and a significant increase in surface microcirculation during the entire 25 minutes of the study period following treatment (P < .001). Females showed significantly higher rates of response than males (P = .003). Each subject experienced immediate decrease in myalgia in both the site treated, in the related distal control site, and in some cases, other distal sites. Pain relief persisted to some extent up to the follow-up visit. There were no adverse reactions.

Conclusion

Gua Sha increases microcirculation local to a treated area, and that increase in circulation may play a role in local and distal decrease in myalgia. Decrease in myalgia at sites distal to a treated area is not due to distal increase in microcirculation. There is an unidentified pain-relieving biomechanism associated with Gua Sha.

Introduction

Gua Sha is a traditional healing technique widely used in Asia, in Asian immigrant communities, and by acupuncturists and practitioners of traditional East Asian medicine worldwide. The indigenous practice of Gua Sha is and has been informed by the experience of its use. It is generally regarded as effective for acute or chronic pain and for mild to severe conditions such as colds, flu, fever, heatstroke, and respiratory problems such as asthma, bronchitis, and emphysema; functional internal organ problems as well as musculoskeletal problems (from fibromyalgia to severe strain, spasm or injury), and is indicated in any cases of recurring fixed pain. It is used as a form of self or familial care in the home1, 2, 3, 4 as well as in clinical practice.5, 6

The term Gua Sha is Chinese. The literal translation for gua is to scrape or scratch.⁷ Sha means sand, sharkskin, or red, raised, millet-size rash.⁸ Sha is also translated as cholera,⁹ wherein sha petechiae resemble cholera’s end-stage rash. Gua Sha in the East, like frictioning in early Western medicine,¹⁰ was used in the treatment of cholera and choleralike disorders.¹¹

Although scraping implies abrasion or injury to the surface skin, with Gua Sha the skin remains intact; there is no abrasion. Gua more accurately describes repeated, unidirectional, pressured stroking with a smooth edge over a lubricated area until sha blemishes appear.5, 7, 12, 13 Stroking is then applied to an adjacent stroke line until sha appears. This continues until the area intended for treatment is covered.

Sha, translated as sand or sharkskin, represents the feeling to the skin after Gua Sha, as though there were sand on it, rough like sharkskin. The red appearance of sha has been confused with that of scarification,¹⁴ but these are two completely different techniques. Scarification is an early Western medical procedure where a scarificator, a spring loaded device containing several to many small blades, is applied to make superficial cuts to an area of the body, often the back.¹⁵

In Vietnamese, Gua Sha is called cao gio² (pronounced cow yo, meaning to scratch out the wind), in Indonesian it is called kerik (ka-drik or ka-drok),¹⁶ in Khmer Cambodian it is called kos khyal (kos kee-yaul),17, 18 and in Laotian it is known as khoud lam (cooed-lum) (A. N., oral communication, December 2003). Common translations include coining, scraping, and spooning. Terms such as dermabrasion, pseudobattery, child abuse, and factitious dermatitis¹⁹ have been misapplied to this therapy.

As Asians emigrated to the West, particularly in the years during and following the Vietnam War, evidence of traditional East Asian domestic and indigenous healthcare practices confronted Western clinicians and authorities, and none was more baffling than the red, rash-effect of Gua Sha. There were case reports in Western literature identifying cao gio,19, 20, 21, 22, 23, 24, 25 coining,16, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 and scraping38, 39 as an indigenous healing technique, but the bulk of articles situated Gua Sha in terms of dermabrasion or pseudobattery, warnings, and or complications mostly to distinguish sha petechiae from signs of abuse.16, 19, 20, 21, 22, 23, 24, 26, 28, 29, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 Still other articles referred to the technique within the larger context of challenges in dealing with the cultural beliefs and practices of an immigrant population.1, 3, 4, 46, 64, 67, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100

In 1976, the first US-licensed acupuncture school (The New England School of Acupuncture) opened in Boston, and Gua Sha was introduced as part of the curriculum.¹⁰¹ When the first People’s Republic of China State sanctioned traditional medicine texts were translated to English in the 1980s102, 103 Gua Sha was omitted. The original English textbook on Gua Sha appeared in English in 1995⁵; the first translation to English of a Chinese text on Gua Sha appeared in 2000.⁶

A 2005 literature search of the Chinese medicine journal database from 1984 to 2004 found 120 articles on outcome studies for Gua Sha, published between 1998 and 2003, but there was no confirmed research on biomarkers.¹⁰⁴ In the Western medical literature database, there have been no studies concerning the physiological effects of Gua Sha.

Gua Sha is reported as a safe procedure¹⁰⁵ with equivocal accounts of complications. In one case reported in Neurology, a patient with headache unresponsive to analgesics or Gua Sha coining is said to have suffered ‘coning’ and a subsequent cerebellar hemorrhage,³² but any link to Gua Sha appears to be coincidental.¹⁰⁴ Mild hematuria in a febrile infant was attributed to renal contusion from coining, without completely ruling out other causes.³³

Another patient was reported as having nummular erythema at the forehead due to coining that was described as placing a lighted candle on a coin and allowing the drippings to heat the coin.¹⁰⁶ The shape and size of the mark shown in the article, as well as the description, indicates the erythema was likely from fire cupping. A more serious case describes a 45-year-old woman who sustained 22% partial and full-thickness burns from alcohol and hot mentholated oil from coining that caught fire. Although the red ecchymosis that is sha has been misconstrued as burns, on careful reading of this case and examination of the image provided, it appears that fire cupping caused the incendiary mishap that burned the patient.²⁶

Medicated lubricants containing camphor, eucalyptus, wintergreen, ginger, and/or other oils may be used in domestic coining practice, and several articles report complications from use of camphor in concentrations larger than those that have come to be regulated in the West. A case of camphor intoxication from use of a camphor-concentrated lubricant for coining was proposed but challenged in JAMA.23, 35 Camphor toxicity was reported in one other case related to coining,⁶³ and a third case was reported where a camphor remedy was applied superficially, unrelated to coining.⁴⁰

Authors agree the primary complication related to Gua Sha coining cao gio is that the appearance of the sha blemishes are mistaken for trauma, i.e., burns, bruises, and abuse when the transitory petechiae do not fit the definition of injury, bruising, purpura, cutaneous stigmata, dermabrasion, or any other factitial dermatological condition. The medical and social reactions that ensue from these mislabels have been detrimental to individual and family health and well-being. A legal brief published in the Wayne State University Law School Journal of Law in Society proposes a law to protect families from medical or legal reproach when using their indigenous medicine.¹⁰⁷

Just such a case of persecution was the subject of a movie made in the United States that became the most popular feature film in China in 2001, The Gua Sha Treatment. Gua Sha has appeared in one other American feature film, The Three Seasons, about postwar Vietnam, starring Harvey Keitel.

In East Asian medicine, all pain is defined as a form of stasis. Common myalgia, that is, muscle aches that come and go, are thought to result from the stress of repeated daily activity, sustained posture, and or exposure to temperature change. If the myalgia pain resolves from touch or movement, it is called Qi stasis. If pain persists or returns at a fixed site, it is called Qi and blood stasis, indicating sha may be present.

The presence of sha is corroborated when pressing palpation results in superficial blanching that is slow to fade (Figure 1) Over time, unresolved sha may be associated with and/or render the body more vulnerable to severe chronic pain, strain, or illness.

Sha stasis can be liberated by sweating from a true fever or through treatment using Gua Sha or cupping. Response to treatment is corroborated by change in symptoms and in clinical signs, including flesh color and topology of the tongue.

There are other methods that are not in wide use for raising sha or are used for focal areas only: pak sha, meaning to slap to raise sha, and tsien (nieh or niu) sha, meaning to pinch to raise sha.5, 13 For example, tsien sha is used at the point on the forehead between the brows (acupuncture point: yin tang) to relieve forehead ache.

Gua Sha, then, is one therapeutic intervention for pain and pathology manifesting as Qi and blood stasis occurring at the surface. The area to be treated is first lubricated with simple oil, typically peanut oil in China, or a medicated oil or balm such as Vicks VapoRub or Badger Balm. In absence of oil, water can be used. For the purposes of this study, plain Badger Balm (W.S. Badger Company, Gilsum, NH) was used (plain Badger Balm has no essential oils or herbs). Tools for Gua Sha include the Chinese soupspoon, an edge-worn coin, a slice of water-buffalo horn, a cow rib, honed jade, or a simple metal cap with a smooth round lip (Figure 2, Figure 3, Figure 5). Any appropriate tool at hand serves the use of Gua Sha in the familial or domestic setting as depicted in the photograph taken in the flower market in Ho Chi Minh City (1997; Figure 4). In the clinical setting, often a slice of water-buffalo horn, jade, or a metal cap is used (Figure 2).

Gua Sha treatment of the back begins at the centerline. A smooth, rounded edge is press-stroked into the flesh enough to contact the fascial layer (Figure 5), but not so hard that it causes pain or discomfort. A stroke line is typically 4 to 6 inches long. Stroking is repeated in one direction until the sha is raised on that stroke line, typically 8 to 12 strokes. Sha petechiae appear slowly, increasing with each stroke. Stroking stops when all the sha is expressed as petechiae at the stroke line, before producing ecchymosis. Gua Sha is then continued at the next stroke line directly adjacent to the one before. This goes on until the area to be treated is covered, taking approximately 5 to 7 minutes in our study.

The patient receiving Gua Sha feels pressured stroking but not pain. Just as the sha petechiae surface, there may be itching, burning, or discomfort that subsides with the cessation of stroking. Benefit for pain and mobility are immediate.

The appearance of sha petechiae is transitory; petechiae immediately begin fading to ecchymosis, completely disappearing in 2 to 4 days (Figure 6). The aim of our study was to describe the microcirculatory effects of Gua Sha on the skin and subcutis in humans by using laser Doppler imaging (LDI).