NEW ORLEANS – With the Asian population estimated to increase to 41 million by 2050 in the United States, expect the demand for experienced dermatologic care of patients with Asian skin to increase in the coming years, Hye Jin (Leah) Chung, MD, said at the annual meeting of the American Academy of Dermatology.
“Asians account for about 60% of the global population,” said Dr. Chung, assistant professor of dermatology at Harvard Medical School, and director of the Asian Skin Clinic at Beth Israel Deaconess Medical Center, Boston. Along with the estimate that Asians are expected to make up 25% of Canada’s population by 2036, “we will most likely encounter more Asian skin type patients in North America,” Dr. Chung said, noting that the Asian population “is very diverse, ranging from skin type 3 in Far East Asia to skin type 5 in India.”
During her presentation, she provided tips for treating hypertrophic scars and keloids in this patient population when intralesional corticosteroids fail. Typically, her first option is to combine an intralesional corticosteroid with 5-fluorouracil (5-FU), a pyrimidine analogue with antimetabolite activity. 5-FU “can cause cell apoptosis of endothelial cells and fibroblasts (which steroids cannot), cell cycle arrest, and TGF-beta [transforming growth factor beta]-induced COL1A2 transcription,” Dr. Chung said. The recommended ratio between 5-FU and steroids in the literature is variable, from a 9:1 ratio to a 1:1 ratio. “In my practice I do not inject more than 100 mg at a time,” she said. Several studies of this approach led by Asian investigators used weekly injections, “but that’s not practical in the U.S. I usually do monthly injections.”
A large systematic review and meta-analysis confirmed that the combination of intralesional triamcinolone acetonide and 5-FU achieved a better efficacy and fewer complications than triamcinolone alone for treating hypertrophic scars and keloids. Potential side effects from 5-FU injections include pain/pruritus, transient hyperpigmentation (especially in skin types 4-6), ulceration, teratogenicity, and transient alopecia.
A more recent meta-analysis comparing the efficacy of multiple drug injections for hypertrophic scars and keloids confirmed that the combination of triamcinolone and 5-FU was superior to bleomycin, verapamil, 5-FU alone, and triamcinolone alone. “And, there was no difference between 5-FU/steroid combination and botulinum toxin A,” Dr. Chung added. “Some parts of the world are using botulinum toxin with mixed results. Based on the amount of toxin required for keloids, this would be cost prohibitive in the U.S.”
Another approach to treating hypertrophic scars and keloids in Asian skin is laser-assisted drug delivery. “First, you can use a fractional ablative laser to create a hole in the epidermis and dermis,” Dr. Chung said. “Then you can apply the suspension topically to the holes. You can also use a steroid ointment or cream after laser treatment for drug delivery.”
Combining pulsed dye laser with steroid injections is another option. Pulsed dye lasers coagulate microvasculature within keloid tissue, “which can cause tissue hypoxia and can decrease growth factors or cytokines for fibrosis within the tissue,” Dr. Chung said. At the cellular level, pulsed dye laser alone can decrease connective tissue growth factor (CTGF), TGF-beta 1, proliferating cell nuclear antigen, and collagen III, and increases matrix metalloproteinase–13 (MMP-13), P53, ERK and p38 MAPK, apoptosis, blockade of AP-1 transcription, and cell cycle changes.
In 2004, plastic surgeons in Korea described a new approach for removing earlobe keloids, which they termed a “keloid fillet flap”. For the procedure, about 50% of the keloid margin is incised with a #15 scalpel blade. “Then you dissect the keloid from the surrounding tissue with a blade or curved scissors,” Dr. Chung said. “Next, you excise the keloid, so you have some dead space. After hemostasis you place the fillet flap to cover the wound. After you trim the redundant tissue, you can close it with epidermal sutures.”
In her clinical experience, she finds the fillet flap “very helpful for fast recovery” and it is associated with less pain. “Several studies have confirmed an excellent improvement of keloids, low recurrence rate, and rare side effects from a fillet flap and adjuvant intralesional corticosteroids. Occasionally, you may see flap necrosis but usually patients do well with topical antibiotics or petrolatum jelly.”
Dr. Chung also discussed her approach to treating papular scars in Asian patients. She described papular scars as underrecognized, anetoderma-like scars on the central face and trunk. “They comprise about 11% of all acne scars but up to 19% of patients with such scars may not recall a history of acne,” she said. Biopsies of papular scars reveal marked reduction or thinning of elastic fibers around hair follicles.
“Papular scars are difficult to treat,” she said. “If you have a conventional Er:YAG or CO2 laser, you can create tiny holes within the scars,” she said, referring to studies on these approaches. Another treatment option is needle-guided radiofrequency, she noted.
Dr. Chung reported having no relevant financial disclosures.