Pigmentary demarcation lines (syn. Futcher’s lines; Voigt’s lines)

Pigmentary demarcation lines (PDL) are areas of an abrupt transition from hyper- to hypo-pigmented or normal skin colour. They can be seen on the limbs, face, and sometimes the trunk. PDL are more commonly reported in Japanese people and black skin, and rarely in white skin. There is a female sex predilection and PDL are more common in pregnancy. 

This chapter, which provides a brief overview of PDL, is set out as follows:

• The differential areas of pigmentation appearing as lines, which are referred to as PDL, arise due to differences in melanocyte distribution
• The cause is largely unknown
• Women are affected more than men; hormonal factors can play a role in some patients 
• Facial patterns, especially types F and G, are seen regularly in other family members

• Most PDL make their appearance at or around puberty
• Some PDL (especially types F-H) remain unnoticed in childhood, only to be revealed after a triggering factor such as puberty, pregnancy, or an acute illness
• In general PDL remain more or less unchanged throughout life. However, they may become more apparent with advancing age, and those reported during pregnancy may disappear after delivery

• In 1975 Selmanowitz and Krivo classified PDL in to five groups namely A to E
• Group A - lines along the upper limb with variable trans-pectoral extension
• Group B - lines along the lower limb 
• Group C - lines on the chest and abdomen in the form of paired lines, median or paramedian 
• Group D - lines on the back, posteromedial demarcation
• Group E - bilaterally symmetrical, obliquely oriented, hypopigmented macules on the chest

• Subsequently, Somani et al. described groups F, G, and H of PDL on the face in Indians
• Group F - represents an inverted cone shaped area of hyperpigmentation over the lateral aspect of the face extending from the lateral orbital rim inferiorly or inferolaterally
• Group G - occurs at a site similar to Group F, but with two inverted cones with a normal patch of skin in between 
• Group H - occurs on the lower face as a linear hyperpigmented band extending from the angle of mouth to the lateral aspect of the chin 

• Some consider periorbital hyperpigmentation (dark circles around the eyes) as an extension of PDL of the face

• Facial lesions can pose cosmetic concern for the patient - treatments provided privately (usually a dermatologist) e.g. topical creams, peels, or laser therapy may benefit some patients