Laser treatment works well on sun-damaged skin

Researchers in the United States have found that sun-damaged skin responds well to laser treatment - which is good news for people with skin badly damaged by exposure to the sun.

The scientists from the Health System Department of Dermatology at the University of Michigan say they have scientific evidence that the appearance of sun-damaged skin may be improved by treatment with a topical product that increases the skin's sensitivity to light, followed by laser therapy.

In a new study the research team treated participants whose skin was sun-damaged with a topical photosensitizer called 5-aminolevulinic acid (5-ALA) and then with a pulsed dye laser.

The treatment, known as photodynamic therapy, increased the collagen levels in the skin and also produced other skin changes that are known to improve its appearance.

They say people with the worst sun damage may respond particularly well to this treatment.

Lead author Dr. Jeffrey S. Orringer says the new scientific evidence shows that photodynamic therapy may be a useful tool to improve the appearance of the skin.

Dr. Orringer who is an associate professor of dermatology at the U-M Health System and director of U-M's Cosmetic Dermatology and Laser Center, says though this type of therapy has been performed in clinical practice for the past few years, there has never been any detailed molecular evidence for why it may work.

The study involved 24 adults, aged 54 to 83 years, who all had significant photodamage on the forearm skin, they were given a three-hour application of 5-ALA followed by pulsed dye laser therapy.

The researchers examined biopsies taken before and at several times after the treatments, and they recorded the molecular changes in the participants' skin at various stages.

They found many molecular changes, but significantly they also found that the levels of the proteins procollagen I and procollagen III increased after treatment - one month after treatment, levels of procollagen I peaked with an increase of 2.65 times the pre-treatment levels and procollagen III peaked one month after treatment with an increase of 3.32 times the pre-treatment levels - other protein levels molecular markers also increased.

Dr. Orringer says the study represents the latest example of U-M's human appearance research program's unraveling of the mechanisms by which popular treatments improve the appearance of the skin.

The team has also studied among other things, the treatment of sun-damaged skin with estrogen, the science behind wrinkle treatments and the effects of smoking on aging skin.

Though photodynamic therapy has been used as a treatment for precancerous lesions called actinic keratoses and for some types of skin cancer, there is little scientific research about its use in appearance-oriented dermatology.

The researchers say more research is now needed to gauge whether the improvements shown in the forearm skin in this study can be replicated on facial skin.

The study appears in the October issue of the Archives of Dermatology.