British Joumal of Plastic Surgery (1990), 43,683-688 0 1990 The Trustees of British Association of Plastic Surgeons

ooO7-1226/90/0043M683/$10.00

Treatment of scars and keloids with a cream containing silicone oil

Y. SAWADA and K. SONE

Departments of Plastic and Reconstructive Surgery and Pharmacy, Hirosaki University School of Medicine, Hirosaki, Japan

Summary-The clinical effect of silicone cream containing 20% of silicone oil was tested on 47 patients with hypertrophic scars and keloids.

A silicone cream/occlusive dressing technique, quite similar in manner to silicone gel treatment, resulted in a remarkable improvement of scars and keloids in 9 of 11 cases (82%) whereas the simple application of the cream onto the scars and keloids of 36 cases resulted in only mild improvement in 8 (22%).

Using the chi-square test, a statistically significant difference was seen between these two treatments (p ~0.01). From these findings, we suggest that occlusion and hydration are the principal modes of action of the silicone gel sheet method and our silicone cream/occlusive dressing technique.

Recent reports have shown the effectiveness of the application of silicone gel sheeting in the treatment of scars and keloids (Perkins et al., 1982; Quinn et al., 1985; Wessling et al., 1985; Quinn, 1987; Merger, 1989). Quinn et al. (1985) described the effectiveness of silicone gel sheet for hypertrophic scars and also commented on its possible mode of action. They concluded that the feature of silicone oil (which is continuously released from gel sheet- ing) most likely to account for its active role in the clinical effect is its low molecular weight. We have therefore investigated the therapeutic effects of silicone oil for the treatment of hypertrophic scars and keloids.

Materials and methods

A medical grade silicone oil, 20 centistokes (360 medical fluid: Dow Corning Japan, Tokyo) was used. The contents of the silicone cream, composed of a mix of two solutions, A and B, are given in Table 1. After warming both solutions to 7X, they were mixed and stirred for 2 hours. The resultant non-viscous white cream, an “oil in water” type, could be spread easily onto skin and washed off with soap following use. The cream was stored at room temperature and neither separation of the oil content nor discolouration was seen after 60 days of shelf storage.

The cream was tested on 47 consenting patients

Table 1 Contents of the silicone cream

Grams

Solution A Silicone oil Stearic acid Cetanol Liquid paraffin Lanolin

Solution B Tri-ethanol amine Glycerin Water

40 I2 3 4.4 1

3 3.6

133

with hypertrophic scars or keloids. These scars and keloids had varied in clinical appearance, age and site. Patients used the silicone cream continuously for at least 3 months, attending monthly for outpatient observation. Lesions that were treated included hypertrophic scars without contracture, at various sites (except scalp) (43 cases) and keloids on the anterior chest (4 cases). The average length of history was 12 months (range 2-48 months). Patients’ ages ranged from 1 to 77 years (average 26 years). In 25 cases (53%) burn injury had caused the scar (Table 2).

Patients were divided into two groups at random and the different treatment methods were carried out for each group. For the 36 patients in group A, the cream was applied to the lesion once or twice daily and covered with a light gauze dressing. For

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Table 2 Clinical silicone cream trial

Group A : 36 cases (14 males, 22 females) Age : 1 to 77 years (average 28 years) Length of history: 2 to 48 months (average 13 months)

Patients Improved .patients

Causes. Bum 19 5 Surgery 11 2 Keloid 2 0

*Others 4 1 Site. Head and neck 6 1

Trunk 10 4 Anterior chest 4 1 Upper extremity 11 1 Lower extremity 5 1

Group B: 11 cases (5 males, 6 females) Age : 1 to 45 years (average 18 years) Length of history: 2 to 48 months (average 10 months)

Patients Improwd patients

Causes : Bum 6 6 Surgery 3 1 Keloid 2 2

*Others 0 0

Site : Head and neck 0 0 Trunk 3 2 Anterior Chest 2 2 Upper extremity 2 2 Lower extremity 4 3

*Others include trauma except for bum injury.

the 11 patients in group B, after application of the silicone cream the lesion was wrapped in a water- impermeable ultralucent plastic film that was fixed to adhere to the entire scar surface. This plastic film was removed when applying the cream once a day and on bathing or for sports. In both groups during the test period, no other therapeutic aids such as a pressure garment or intralesional steroid injection were used. Infected or ulcerated scars and keloids were excluded from the study. Initially, side-by- side testing was carried out using silicone cream and Vaseline as a control. However, for some group B cases the side-by-side testing was discontinued because covering only part of the lesion with the thin plastic film proved too awkward.

Assessment of therapy was made between 3 and 5 months after the initial application of the cream, on the basis of the criteria given in Table 3. These five factors, being characteristics common to all lesions, were graded in ascending severity. The cream was considered beneficial if scars and keloids showed improvement in at least three out of the five factors listed, and if an improvement was seen in at least two factors in lesions with one or more

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Table 3 Evaluation of scar and keloid

Redness + + + severe redness, associated with telangiectasia ++ redness, disappears with pressure + no redness, but black appearance - normal skin colour

Elevation +++ ++ +

Hardness +++ ++ +

Itching +++

++ +

over 8 mm in height above surrounding skin 4to8mm 1 to4mm flat or depressed scar

very hard, like cartilage rubbery hard partially soft soft (like normal skin)

severe itchy sensation or constantly itchy, with signs of scratching occasional itchy sensation, moderate and tolerable sometimes itchy no itchy sensation

Tenderness or pain + + + severe irritable pain ++ moderately irritable pain + sometimes painful

without pain

factors scoring (-) at the start of treatment. When concurrent side-by-side testing had been carried out, the cream was considered beneficial if greater improvement was noted compared to the control.

Results

The silicone cream caused no serious side-effects in either group, nor did the lesion worsen. However, in three cases in group B a mild skin rash was seen but only in the healthy skin surrounding the scar that had also been covered by the plastic film. This is thought to have been caused by retention of sweat beneath the plastic film and might have been prevented if healthy skin had not been covered. The majority of patients felt that the silicone cream was easy to apply and that it spread well without feeling sticky. Moreover, five patients who had been treated with a pressure garment prior to the silicone cream treatment considered the cream to be more convenient. In both groups the scar surface presented a smooth, glossy appearance after the cream had been used for a few weeks.

In group A, only eight (22%) of the 36 cases were assessed as “improved”. In these cases the scar improved gradually and the degree of improvement was slight. Among these eight cases fading of

TREATMENT OF SCARS AND KELOIDS WITH A CREAM CONTAINING SILICONE OIL

rig. 1

Fig. 2

Figure l-(A) A one-year-old boy with a hypertrophic scar on the right shoulder 6 months after burn injury. The scar did not respond to conservative treatment, was red, raised, firm and frequently scratched. (B) Appearance at 4 months after the silicone cream/occlusive dressing treatment. Reduction in redness, height and hardness resulted and the patient no longer scratched the scar. Figure 2-(A) A 23-year-old woman with a hypertrophic scar 5 months after a traffic accident. It was itchy and tender. The scar was divided into two areas: (right) the silicone cream/occlusive dressing applied to one part and (left) simple Vaseline to the other. (B) Appearance 4 months after start of treatment. The portion treated with the silicone cream/occlusive dressing was less tender and softer and had decreased in height compared to the Vaseline-treated portion. The dotted line shows the boundary between the treatment areas (Si = silicone cream; Vo = Vaseline ointment). Neither pain nor tenderness was noted.

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Fig. 3

Fig. 4

Figure S(A) A 23-year-old woman with a spontaneous keloid on the anterior chest that showed continuous growth beyond its initial boundaries. (B) Three months after treatment with the silicone cream/occlusive dressing, the keloid had stopped growing and become softer. Decreased itching, pain, height and redness resulted. Figure 4-(A) A 16-year-old youth with a hard bum scar on the left upper extremity about 8 months after injury. The scar showed continuous growth and sometimes ulcerated. In this case, we thought that surgery of the scar contracture would be necessary in the near future. (B) Appearance 3 months after treatment with the silicone cream/occlusive dressing. A remarkable reduction in redness, itching and pain resulted. The scar became softer and decreased in height. No scar contracture developed.

TREATMENT OF SCARS AND KELOIDS WITH A CREAM CONTAINING SILICONE OIL 687

redness was seen, whereas lessening of itching was noted in six, less tenderness and elevation in five, but softening of the scar in only four.

In nine (82%) of the 11 cases in group B, the scar showed a more rapid and obvious improvement, with less redness, tenderness, itching and hardness (Figs l-4). A statistically significant difference with the chi-square test was seen between groups A and B (~~0.01).

The features of improvement were as follows: first, the surface became wet-looking with no accumulation of fluid, and hyperkeratosis, if present on the scar surface, disappeared. Then decrease in the redness and itching occurred followed by flattening of the scar or keloid. In general, immature scars responded quickly but the response in keloids was slow.

Discussion

Silicone, including silicone oil, is a biologically inert substance that is widely used in the field of plastic surgery (Barley, 1987). Sensitisation to silicone oil does not occur, nor does it cause irritation, and it has been used successfully for burns rehabilitation especially for the burned hand (Helal et al., 1982; Miller et al., 1985). Silicone oil has been widely used in ointments and has also been applied on the feet to prevent warm water immersion foot (Plein and Plein, 1953; Taplin and Zaias, 1966; Buckels et al., 1967). In such instances it was strongly hydrophobic and prevented inflam- mation of the foot (Taplin and Zaias, 1966; Buckles et al., 1967). However, as far as we can determine, the use of silicone cream for the treatment of hypertrophic scars and keloids has not been previously reported.

While the efficacy of silicone gel sheeting in the treatment of scars and keloids has recently been confirmed, how this happens has yet to be ex- plained. Quinn et al. (1985) have speculated that silicone oil that is continuously released from silicone gel is probably responsible since a water- impermeable plastic plate showed no efficacy for hypertrophic scars. However, Davey (1986) thinks that silicone gel’s water impermeability may be how it works.

The results of our observations indicate that in patients who were given an occlusive dressing over the silicone cream and the scar, improvement was significantly better than in those who used the cream alone. This silicone cream/occlusive dressing method is similar to the silicone gel treatment.

From such findings, we suggest that occlusion and hydration are the principal modes of action of both the silicone gel method and our silicone cream/ occlusive dressing method.

With regard to the treatment of hypertrophic scars and keloids with silicone gel, Mercer (1989) has reported that silicone gel showed no response in some keloids, mainly because of the difficulty in keeping the gel in contact with the entire surface. Scars and keloids usually have rough surfaces and are elevated from the surrounding healthy skin, so that maintaining close contact between the gel sheet and scar surface is difficult. We also encoun- tered similar experiences in group B, two cases showing no response initially. These cases involved scars on the foot and scapula and it was found that the plastic film would not maintain constant contact with the scars because of the local shearing effect of movement, as the film had been only lightly attached with surgical tape. Later in the study the plastic film was fixed sufficiently tightly to the scar to maintain continuous close contact. For large, very uneven or elevated scars our silicone cream/ occlusive dressing is the more suitable method because the plastic film ensures overall contact of the cream with the scar surface. Although further study is essential, this method has been found to be useful in the treatment of hypertrophic scars and keloids.

Acknowledgement

The authors would like to thank Dr Mitsuo Sugawara, Professor in the Department of Plastic and Reconstructive Surgery, Hirosaki University School of Medicine, for his kind advice.

References

Barley, S. A. (1987). The use of silicones in plastic surgery. Plastic and Reconstructive Surgery, 51, 280.

Buckelq L. J., GIII, K. A. Jr. and Anderson, G. T. (1967). Prophylaxis of warm-water-immersion foot. Journal of the American Medical Association, MO,68 1,

Davey, R. B. (1986). The use of silicone gel and silastic foam in bum scar management. How does it work? Presented at the 7th Congress of the International Society for Bum Injuries, Melbourne, 23-28 February 1986.

HelPI, B., Chapman, R., Ellis, M. and GIfFord, D. (1982). The use of silicone oil for mobilization of the hand. Journal of Bone and Joint Surgery, 64B, 67.

Mercer, N. S. G. (1989). Silicone gel in the treatment of keloid scars. British Journal of Plastic Surgery, 42,83.

MBIer, J., Hardy, B. and Spira, M. (1985). Treatment of bums of the hand with silicone dressing and early motion. Journal of Bone and Joint Surgery, 47A, 938.

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Perkins, K., Davey, R. B. and W&is, K. A. (1982). Silicone gel: a new treatment for bum scars and contractures. Burns, 9, 201.

Plein, J. B. and Plein, E. M. (1953). A preliminary study of silicone oils as dermatological vehicles. Journalof the American Pharmaceutical Association, 42,?9.

Quinn, K. J. (1987). Silicone gel in scar treatment. Burns, 13s, 33.

Quinn, K. J., Evans, J. H., Courtney, J. M. and Gaylor, J. D. S. (1985). Non-pressure treatment of hypertrophic scars. Burns, 12, 102.

Taplin, D. and Zaias, N. (1966). Topical immersion foot syndrome. Military Medicine, 131,814.

Wesling, N., Ehleben, C. M., Chapman, V., May, S. R. and StU, J. M. Jr. (1985). Evidence that use of a silicone gel sheet increases range motion over bum wound contracture. Journal of Burn Care and Rehabilitation, 6, 503.

The Authors

Yukimasa Sawada, MD, Associate Professor, Department of Plastic and Reconstructive Surgery, Hirosaki University School of Medicine, 53 Hon-cho, Hirosaki City, Aomori Prefecture 036, Japan.

Ken Soae, MD, Research Instructor, Department of Pharmacy, Hirosaki University School of Medicine.

Requests for reprints to Dr Sawada.

Paper received 10 April 1990. Accepted 31 May 1990.