Type B pigmentary demarcation lines of pregnancy involving the anterior thighs and knees.

Pigmentary demarcation lines are abrupt transition lines between the areas of deeper pigmentation and the areas of lighter, normal pigmentation. Type B pigmentary demarcation lines involve the posterior medial portion of the lower extremities and are more commonly associated with pregnancy. We present a case of pigmentary demarcation lines of pregnancy with erythematous changes, involving both the anterior and posterior aspects of the lower extremities.