๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
LINEAR HYPERPIGMENTATION
Linear hyperpigmentation can have a variety of etiologies, including postinflammatory changes, drug reactions, and mosaic genetic alterations that result in hypermelanosis along the lines of Blaschko (see Ch. 62). Pigmentary demarcation lines reflect normal dorsalโventral patterning of the skin. In the evaluation of a patient with linear hyperpigmentation, an initial step is to determine whether or not the hypermelanosis follows the lines of Blaschko.
Fig. 67.9 Minocycline-induced pigmentation. The distribution on the shins and the grayโblue color can be similar to that seen with antimalarials.