Title 1: Pseudomelasma title 2: what you didn

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Title 1 Pseudomelasmatitle 2 what you didnt
know about melasma!

• By
• Dr Abdullah Al Somari
• Dr Saad Al Mohizea
• Dr Ghada Bin Seef
• 2007

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• What is your diagnosis?

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• Picture 1

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• How would you treat?

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• Picture 2

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• Melasma is not homogenous
• The site of melasma is different
• Melasma may respond to treatment
• What is the diagnosis then?

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• Pigmentary Demarcation Lines
• (PDL)

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Normal Pigmentation

• Pigmentation is generally perceived as an
  adaptation response of humans to UV radiation
• considerable variation even in a single race
• skin color of Caucasians ranges from fair to
  brown
• The constitutive pigmentation also differs
• females having a lighter color than males
• Distribution of melanin is also uneven
• in Caucasians the upper thigh is the darkest
  and the lumbar, the lightest area

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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

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Pathogenesis?

• More common in females
• More common in darker races
• PDLs are dominantly inherited
• Phylogenetic importance?
• Cutaneous Mosaicism?
• Neural influence?
• Strong hormonal influence

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Mosaicism?

• Two types functional mosaics, resulting from X
  inactivation or lyonization,and genomic mosaics,
  caused by postzygotic autosomal mutations.
• Could explain the familial aggregation and the
  female preponderance
• Either the maternal or paternal X chromosome is
  lyonized (deactivated) randomly, but it remains
  the same for all the descendants of that cell
• Because of this process the heterozygous state of
  various X-linked gene defects may lead to a
  cutaneous mosaic.
• Streaky or patchy pigmentation may be a clue to
  the presence of mosaicism

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HORMONAL INFLUENCE

• Hormonal influence over pigmentary
  characteristics has been documented
• preponderance of females exhibiting these lines
  could be related to sex hormones
• High levels of Estrogen Progesterone and MSH
• Persistance of PDL after pregnancy with estrogen
  therapy
• Hormones are probably aggravating PDL and not
  causing it

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Neural theory

• Maleville concluded that the axial-neural theory
  is the most commonly accepted in opposition to
  that of pigmentary mosaicism as defended by Krivo
• They coincide with cutaneous nerve distribution.
• Compression by the enlarged uterus of peripheral
  nerves issuing at S1S2 is proposed as a
  mechanism of these changes in type B

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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

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PDL is common!

• Body PDL
• Pigmentary changes are seen in nearly 85 of
  pregnant women
• About 25 of black Africans show sharply
  demarcated pigmentary lines either at the
  anterolateral upper arm or posteromedial part of
  the lower limbs (Type A and B)
• More in females (except type c with slight male
  preponderance)
• Can be associated with an erythematous component
• PDL over the face
• (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)

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History AND Examination

• Asymptomatic
• Strong family history (sister, mother)
• Homogeneous and sharply demarcated
• Symmetrical
• Associated with thyroid disease?
• 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.

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SKIN BIOPSY

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

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Old groups(non facial)
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New groups (facial PDLs)
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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

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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

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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

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Differential diagnosis

• melasma
• post-inflammatory pigmentation
• nevus of Ota or Ito
• melanocytic nevus
• Tuberus sclerosis

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Clinical pearls

• Melasma occurs as a blotchy pigmentation over
  the malar areas just below the PDL F, and may
  involve other parts like the nose, supra-orbital
  areas or upper lips.
• Dermal nevi often have a bluish or greenish
  black color and a scleral component.

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Treatment

• PDL is a treatment challenge
• Even if they respond to peels or laser they recur
  promptly within months
• Better left alone?
• Camouflage
• Effective treatment of futchers line with
  alexandrite laser?

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White with black stripes or black with white
stripes?
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