Idiopathic Guttate Hypomelanosis Clinical Presentation

Updated: Jun 10, 2022
  • Author: Christopher R Gorman, MD; Chief Editor: William D James, MD  more...
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Typically, idiopathic guttate hypomelanosis develops first on the legs of fair-skinned women in early adult life. Later, it may spread to other sun-exposed areas, such as the arms and the upper part of the back. The face is inexplicably not involved early in idiopathic guttate hypomelanosis. A familial tendency to develop idiopathic guttate hypomelanosis has been noted. [11]


Physical Examination

Idiopathic guttate hypomelanosis consists of discrete, angular or circular macules that are 1-3 mm in diameter. However, lesions may measure up to 10 mm in diameter. These lighter-than-normal skin macules are off white, hypopigmented, or achromic. They are often noted first on the anterior aspects of the legs. Later, they appear on the forearms. The distribution seems to be photo related, except for the face, which is affected later than the limbs.