Biomedical Engineering Reference
In-Depth Information
(
A
)
(
B
)
(
C
)
(
D
)
(
E
)
Figure 13.12
(
A
) A 55-year-old Thai woman with melasma, before treatment. (
B
) Erythema was noted 1 week after two-pass CO
2
laser resurfacing. (
C
) Postinfl am-
matory hyperpigmentation developed 4 weeks after treatment. (
D
) Again 4 weeks after treated with hydroquinone 4% cream twice daily, hyperpigmentation had
faded. (
E
) Pseudohypopigmentation without recurrence of melasma on the resurfaced area 4 years after treatment. She received no further topical bleaching agent
but used only an SPF 30, broad spectrum sunscreen.
Dermal Pigmented Lesions
Nevus of Ota
Nevus of Ota, a dendritic melanocytosis of the papillary and
upper reticular dermis involving the eye and surrounding skin
innervated by the fi rst and second branches of the trigeminal
nerve, is a cosmetic problem commonly found in Asians but is
also seen in blacks and whites. An incidence of 0.6% has been
noted in the Japanese (108). Malignant degeneration has occa-
sionally been reported (109,110). Studies in fair- and dark-
skinned populations have demonstrated that red (QS ruby)
(111-113), near infrared (QS alexandrite) (114-117), and QS
Nd:YAG (76,118) lasers are very useful for treating nevus of
Ota with fading over several months following each treatment
session.
