Hypertrophic scars respond to low-fluence pulsed dye laser

Elizabeth Tanzi, M.D., a dermatologist and co-director of laser surgery at the Washington Institute of Dermatologic Laser Surgery in Washington, D.C., says it's important to distinguish between hypertrophic and keloid scarring when talking about treatments.

"Hypertrophic scars, on the whole, respond better than keloids to many of our treatments," she says.

"The vast majority of patients respond favorably," she says. "There are conflicting reports in the literature on the use of the pulsed dye laser for the treatment of hypertrophic scars. However, if you read the information carefully, it suggests that hypertrophic scars respond better to lower fluences - sub-purpuric."

According to Dr. Tanzi, it is a common misconception that higher energy equals better results in the treatment of hypertrophic scars. She typically uses a 10mm spot size and fluences no higher than 5 to 5.5 J/cm² when treating hypertrophic scars with the 585-nm pulsed dye laser.

"My experience is that non-overlapping laser pulses at low to mid fluences will produce the best results," she says.

Using this approach, the laser is her preferred treatment for hypertrophic scars because it is noninvasive, no special care is required after treatment, and patients are relatively comfortable throughout treatment.

Dr. Tanzi evaluates whether patients with darker skin tones - including Fitzpatrick skin types V and VI - may be candidates for the laser on a case-by-case basis. These patients are more difficult to treat with the modality because the color in their skin can interfere with laser treatment. Potentially, they can have trouble with dyspigmentation and skin peeling after treatment, she says.

Other modalities for the treatment of hypertrophic scars include the "old standby," intralesional steroids. Steroid injections tend to do a good job in softening and flattening scars and decreasing irritation. However, the treatment can have side effects: The steroid is systemically absorbed and can cause the skin to thin and new blood vessels to form.

Other noninvasive treatments available for the treatment of hypertrophic scars include silicone sheeting and pressure dressing.

"I use them very infrequently for the management of hypertrophic scars because I find the pulsed dye laser yields effective results on its own," Dr. Tanzi says.

Tackling keloids Dr. Tanzi does not use intralesional steroids in the treatment of hypertrophic scarring. She only uses the injections in the treatment of very thick keloids.

A keloid, she says, is fundamentally different than a hypertrophic scar.

"They have a tendency to keep growing and they can become very thick," Dr. Tanzi says. "In those cases, I like to combine the injectable steroid with the laser. Other modalities that have been used successfully are other injectables, such as 5-fluorouracil (5-FU) to help shrink the scarring."

Dr. Tanzi typically waits at least four to six weeks between injections and about six weeks between laser treatments.

Some dermatologists use injectable interferon in the treatment of keloids. Another application in trials, according to Dr. Tanzi, is that of imiquimod, which in early studies has shown promise in helping to induce local interferon at the application site.

"The reason why keloids are very infrequently removed surgically without combining other treatments," Dr. Tanzi says, "is that they have a high recurrence rate with surgery alone. Surgical removal, therefore, is often done in combination with other treatments."