Tears of joy: Novel onion extract cream offers protection from sun's rays

November 1, 2009
Louise Gagnon

Louise Gagnon is a medical writer and editor based in Oakville, Ontario, Canada.

Use of onion extract cream to treat post-surgical scars improves the appearance of scars after surgery.

Key Points

High Point, N.C. - A small study has found that use of onion extract cream to treat post-surgical scars improves the appearance of scars after surgery as it provides sun protection for patients.

When patients undergo excision of lesions such as seborrheic keratoses, dermatologists often remove the lesions with a superficial shave excision, which is aimed at minimizing dermal scarring. Scars form on the skin via a three-stage process, and the process can last up to two years after an injury.

Protecting scars

The latest formulation of topical onion extract comes in a cream, is therapeutically equivalent to an older gel formulation and contains ultraviolet A and ultraviolet B sun protection - equivalent to an SPF of 30 - to protect scars from ultraviolet rays of the sun, Dr. Draelos says.

"In order to get sunscreen with the onion extract, it has to take the form of a cream," Dr. Draelos says. "Patients would use the cream for sun protection and use the gel if they don't require sun protection," she says.

Efficacy study

Subjects in the study examining the efficacy of the onion extract cream had symmetrical seborrheic keratoses at least 8 mm in diameter on the upper chest, and had undergone excision of these lesions.

Investigators first allowed two weeks for the surgical sites to heal, and then randomized 20 subjects to evaluate the efficacy of the onion extract cream.

At the baseline visit, subjects underwent photography of their scars, a self-assessment of their own scars and a scar assessment by investigators. Four-point ordinal scales were used to measure scar assessment. In addition, transepidermal water loss was measured.

Participants in the study applied a layer of the onion extract gel and cream three times daily for eight weeks, putting a layer of the onion extract cream on the right chest scar and a layer of gel on the left chest scar or the reverse.

Researchers observed that the gel formulation and the cream formulation demonstrated comparable efficacy in making scars less visible to the human eye. They concluded that onion extract cream with SPF 30 is as effective as the onion extract gel formulation in making the cosmetic appearance of post-surgical scars better.

Previous studies

A previous study titled The ability of onion extract gel to improve the cosmetic appearance of postsurgical scars (Draelos ZD. J Cosmet Dermatol. Jun 2008;7(2):101-104) concluded that patients who received post-surgical application of an onion extract gel had markedly enhanced scar softness, redness, texture and global appearance at the site of excision at four weeks, six weeks and 10 weeks, compared to patients who received no topical treatment post-surgically, according to an assessment by an independent investigator.

The significant improvement observed in the 2008 study may have been due to the moisturizing properties of the onion extract gel creating a better environment for wound healing, according to Dr. Draelos.

A 2002 study titled Effect of Mederma on hypertrophic scarring in the rabbit ear model (Saulis AS, Mogford JH, Mustoe TA. Plast Reconstr Surg. July 2002;110(1):177-183; discussion 184-186) demonstrated that onion extract, while failing to decrease scar hypertrophy, improved collagen organization, she says.

Disclosure: Dr. Draelos received a grant to do research for Merz Pharmaceuticals.

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