INTRODUCTION
Sebaceous hyperplasia is a common benign proliferation
of sebaceous glands. Lesions are characterized by multiple
lobules emptying into a large central duct. They normally
present as round, yellow, umbilicated papules.1 Although
a number of treatment techniques have been reported, they seldom
provide a complete cure and often lead to recurrence. Acid
destruction, ablative lasers, electrodessication and curettage,
isotretinoin, cryotherapy with a copper probe or cotton swab, visible
light lasers, intense pulsed light, and finally photodynamic
therapy using aminolevulinic acid have all been applied to the
sebaceous hyperplasia lesions.1-4 Although individual sebaceous
glands range from 200 to 500 µm in diameter, larger sebaceous
hyperplasia lesions usually range from 1 to 2 mm in diameter and
can extend 2 mm deep in the dermis. The depth of the lesions
demands more than a surface therapy if rapid recurrences are to
be avoided. On the other hand, too deep a treatment can result
in scarring. Most destructive techniques are nonspecific and are
associated with potential complications such as atrophic scarring
and dyspigmentation. Isotretinoin has been shown to temporarily
shrink sebaceous hyperplasia, but the lesions recur with
discontinuation of therapy, and there is a risk of hepatotoxicity,
agranulocytosis, hypertriglyceridemia, and teratogenic effects.5,6
Laser treatment of sebaceous hyperplasia has the potential advantage
of selectively targeting the sebaceous gland. Thus far,experience with laser treatment of sebaceous hyperplasia has
been limited to devices that are commonly used to treat photodamage
but are lacking in selective properties that can specifically
target sebaceous glands. These lasers include the carbon dioxide
(CO2), erbium-doped yttrium aluminum garnet, and 1,450-nm diode
lasers, which target water, and the pulsed dye laser (PDL),
which targets hemoglobin. The absorption spectra of human fat
have identified 1,210 and 1,720 nm as relative peaks.7 It has been
shown that at 1,720 nm, the photothermal excitation of fat is twice
the background skin.8 Therefore, the potential of selectively targeting
fatty tissues, such as sebaceous gland hyperplasia, with
preservation of the overlying skin is feasible by using the 1,720-
nm near-infrared lipid absorption band. To date, a commercially
available laser with the wavelength of 1,720 nm does not exist.
In addition to 1,720 nm, other wavelengths that show selective
fat absorption include 920 nm and 1,210 nm. Recent work has
characterized the selectivity of 1,210 and 1,720 nm for the sebaceous
gland.7,8 The 1,720-nm laser selectively targets sebaceous
hyperplasia with minimal damage to surrounding tissues. A
simple ex vivo "bacon study" demonstrated selective heating
of the fatty tissue with minimal effect on the muscle tissue (Figure
1). However, human studies are lacking. In this report, we
present the first clinical application of a novel 1,720-nm laser in
the treatment of sebaceous lesions in humans.