Pseudomelasma

1
Pseudomelasma

• By
• Dr Abdullah Al Semari
• 2007

2
(No Transcript)
3

• Pigmentary Demarcation Lines
• (PDL)

4
PDL

• Pigmentary demarcation lines (PDL) were first
  described by Matzumoto on the upper and lower
  limbs of Japanese people in 1913
• Also known as Futchers or Voights lines
• Pigmentary demarcation lines are borders of
  abrupt transition between more deeply pigmented
  skin and that of lighter pigmentation
• They do not correspond to Blaschkos lines or
  dermatomal lines but to voigt lines
• Considered by some to be a variant of normal
  pigmentation

5

• Types of PDL 
• A Lateral aspect of upper anterior portions of
  arms across pectoral areas
• B posterior medial portions of lower limbs
• C vertical hypopigmented line in pre and
  poststernal area
• D posterior medial area of the spine
• E Bilateral aspect of the chest from the
  mid-third of the clavicle to periareolar skin

6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9

• Modified Types of PDL 
• A Lateral aspect of upper anterior portions of
  arms across pectoral areas
• B posterior medial portions of lower limbs
• C vertical hypopigmented line in pre and
  poststernal area
• D posterior medial area of the spine
• E Bilateral aspect of the chest from the
  mid-third of the clavicle to periareolar skin
• F  Straight or convex line on the face

10
(No Transcript)
11

• PDL over the face
• In 2004 in indain study
• (6) were found to have demarcation lines on the
  face (indians).
• lines were far more common in women (9) than in
  men (0.75)
• Positive family history in (61)

12
(No Transcript)
13
New groups (facial PDLs)
14
Group F

• V shaped or as an inverted cone on the lateral
  aspect of the face in the region between the
  malar prominence and the temple.
• Bilateral and symmetrical.
• In about 20 of cases these patches merged with
  infraorbital pigmentation

15
Group G

• Two inverted cones lying in close proximity,
  looking like the letter W
• Both patterns F and G showed evenly diffuse
  pigmentation with a rather well defined margin
• no satellite lesions, speckling, increased hair
  or any textural change

16
Group H

• Two symmetrical linear bands of hyperpigmentation
• extending from just below the angle of the mouth
  to the lateral aspects of the chin.
• There might be an additional band running just
  below and parallel to the lower lip, joining the
  two oro-mental bands

17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Pathogenesis?

• Neural influence?
• Cutaneous Mosaicism?
• Strong hormonal influence

22
Neural theory

• They coincide with cutaneous nerve distribution
• Maleville concluded that the axial-neural theory
  is the most commonly accepted

23
Neural theory

• NEURAL control of pigmentation?
• Differences in melanogenesis noted across these
  lines my correspond to an absence or reduced
  expression of certain proteins between nerve
  endings in neural territories controlled by
  different homeobox gene during development

24
Mosaicism?

• Two types functional mosaics, resulting from X
  inactivation or lyonization,and genomic mosaics,
  caused by postzygotic autosomal mutations.
• Streaky or patchy pigmentation may be a clue to
  the presence of mosaicism

25
Facial PDL

• Usually complain of melasma or periorbital
  darkening
• Asymptomatic
• Positive family history (sister, mother)
• Homogeneous and sharply demarcated
• Symmetrical
• Maybe Associated with other PDLS
• ONSET AND COURSE
• All the facial PDLS first made their appearance
  around puberty Whereas the classical types
  presentesd Earlier in childhood
• Facial PDLs become more apparent with advancing
  age.

26
SKIN BIOPSY

• Unremarkable except for hyperpigmentation of the
  basal cell layer without inflammatory infiltrate
  or melanophages in the upper dermis

27
Differential diagnosis

• melasma
• post-inflammatory pigmentation
• nevus of Ota or Ito

28
Treatment

• PDL is a treatment challenge
• Better left alone?
• Camouflage

29
(No Transcript)
30

• PDL should be left alone!