Recent studies show that port wine stains (PWSs) are likely to require multiple courses of treatment over a patient's lifetime. Applying topical anti-angiogenic creams may prevent eventual darkening of treated PWSs, an expert says.
When PDLs became available, "The first study gave the impression that after an average of six to seven treatments, patients would achieve 100 percent clearing, and that was it (Tan OT, Sherwood K, Gilchrest BG. N Engl J Med. 1989 Feb 16;320(7):416-421)," says Elizabeth McBurney, M.D., clinical professor of dermatology, Tulane University School of Medicine, and a Slidell, La., dermatologist in private practice.
However, she says that in reality, "Seventy to 80 percent lightening is probably a more reasonable expectation."
Over the past two decades, she says, manufacturers have greatly improved PDL technology.
"We now have longer pulse durations, epidermal cooling devices, variable spot sizes and increased energy trains per pulse," Dr. McBurney tells Dermatology Times.
Furthermore, PDLs now offer two wavelengths - 595 nm and 1,064 nm - and some PDLs have added local vacuum pressure. By extending the original PDLs' wavelength from 585 nm to 595 nm, she says, "We achieve deeper penetration."
Some newer laser units have combined the PDL with the Nd:YAG laser and offer two wavelengths: 595 nm and 1,064 nm.
With all these innovations, the complication rate for PDL treatments of PWSs is extremely low, Dr. McBurney says.
One study of 51 patients followed for a median of 9.5 years has shown that "very definitely, there is continued darkening of the lesions even after we've treated them with the PDL (Huikeshoven M et al. N Engl J Med. 2007 Mar 22;356(12):1235-1240)," she says.
Accordingly, she says, "It's vital that we emphasize to the patients and their parents, if they're young children, that they can't expect to get one series of treatments and that's it for the rest of their lives. It's very likely that patients will need some touch-up treatments later."
Additionally, a preliminary study conducted in a rodent model showed that treating the vascular portion of a PWS with a PDL and applying rapamycin cream afterward prevented revascularization for the study's duration (Phung TL et al. Lasers Surg Med. 2008 Jan;40(1):1-5).
This study indicates that for optimal results, dermatologists should immediately follow PDL treatments with topical anti-angiogenic medications, Dr. McBurney says.
If physicians can clear PWSs with the laser, then use a topical cream to prevent revascularization, "We might be able to prevent the darkening that occurs down the line after treatment," Dr. McBurney says.
Disclosure: Dr. McBurney reports no relevant financial interests.
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