Pigmented

Question 1

CARP pathophysiology

Answer 1

• abnormal host reaction to Malasezzia, although only isolated in 50% of cases resulting in abnormal keratinocyte differentiation
• responds to tetracyclines –> ? antibiotic or anti-inflammatory
• Associated with: obesity, insulin resistance, thyroid dysfunction and Cushing disease

Question 2

CARP Histology

Answer 2

• Hyperkeratosis and papillomatosis, loss of granular layer

- Increased melanin in the basal cell layer and stratum corneum

Question 3

CARP Clinical

Answer 3

1-2 mm hyperkeratotic papules on the turnk that coalesce and form greyish-blue plaques, confluent in centre and reticular on periphery

Question 4

DDx for CARP

Answer 4

• AN
• Macular amyloid
• Darier
• Epidermal naevus
• Planar warts
• Pit versicolor
• Seb k
• Retention hyperkeratosis

Question 5

CARP Management

Answer 5

• no treatment if no cosmetic bother
• weight reduction/remove offending agent
• First line: minocycline appears to be most beneficial
• Second: topical and systemic antifungals
• Third: low dose isotretinoin

Question 6

Ephiledes epidemiology and pathogenesis

Answer 6

• More common in blondes and red heads
• Sun induced melanogenesis and transport of an increased number of fully melanised mealnosomes from melanocytes to keratinocytes

Question 7

Ephelides clinical

Answer 7

• Sun exopsed areas
• 1-3 mm in diameter - round, oval or irregular in shape
• Marker of UV induced damage
• High freckle density –> high risk of melanoma

Question 8

Ephelides histo

Answer 8

• Keratinocytes have increased melanin content

- Occasionally, melanophages in papillary dermis

Question 9

Ephelides ddx

Answer 9

• Simple lentigines
• Solar lentigines
• CALMs
• Junctional naevi

Question 10

Ephelides treatment

Answer 10

• Photoprotection
• Lighten: topical retinoids and hydroquinone
• Broadband light therapy

Question 11

CALMS pathogenesis

Answer 11

• Increased melanogenesis and increased melanin content in keratinocytes
• Biallelic NF1 inactivation has been identified in melanocytes from CALMs in patients with NF1 and McCune Allbright

Question 12

CALMS clinical

Answer 12

• Light brown macule, can be anywhere except mucous membrane
• Usually 2-5 cm
• Dermoscopy: homogenous brown patch, with perifollicular hypopigmentation
• Unilateral
• Associations:
  
  • NF
  • McCune Albright
    
    • Triad of macular patches, bony lesions and endo (overactive hormones)
    • GNAS gene mutation

Question 13

CALMS histology

Answer 13

• Slightly increased melanin content in basilar keratinocytes
• Adnexal epithelium spared of hyperpigmentation
• DOPA stained: density of melanocytes higher in both CALMS and normal adjacent skin
• Melanin macroglobules may be present

Question 14

CALMS ddx

Answer 14

• Pigmentary mosaicism - segmental pigmentation disorder, linear naevoid hyperpigmentation
• Early naevus spilus –> before speckles appear
• Becker melanosis
• Mastocytoma
• Mosaic neurofibromatosis
• PIH
• Lentigines, acquired melanocytic naevi
• Flat congential melanocytic naevi

Question 15

CALMS treatment

Answer 15

• Never undergoes malignant change
• Laser treatment - need to discuss risks, requires multiple treatments –> 12 CALMS treated with Q switched ruby laser –> 50% developed repigmentation within 6 months

Question 16

Becker melanosis epidemiology

Answer 16

• usually acquired
• most often appear second and third decades of life
• M>F

Question 17

Becker melanosis pathogenesis

Answer 17

• Organoid hamartoma of ectodermally and mesodermally derived tissues
• Increase in androgen receptors and possibly heightened sensitivity to androgens has been postulated
• For congenital –> ?postzygotic mutations in beta-actin

Question 18

Becker melanosis clinical

Answer 18

• second or third decade of life
• sometimes following intense sun exposure
• unilateral, usually upper quadrant of anterior or posterior chest but have been described elsewhere
• ranges from a few centimetres to >15 cm
• Can become slightly thickened with hypertrichosis
• May enlarge for a year or 2, then stabilise
• No malignancy change ever been reported
• Associated hypoplastic changes: hypoplasia of the breast, areola, nipple, arm, scoliosus, etc
• More likely to have associated changes in females

Question 19

Becker melanosis histo

Answer 19

• Acanthosis, hyperkeratotisis +/- mild papillomatosis
• Regular elongation of the rete ridges and hyperplasia of the pilosebaceous unit
• Melanin content in keratinocytes increased

Question 20

Becker melanosis ddx

Answer 20

CALM, congenital melanocytic naevus, plexiform neurofibroma, congenital smooth muscle hamartoma

Question 21

Becker melanosis Rx

Answer 21

• Electrolysis, waxing, camouflage makeup

- Laser treatments - Q switched ruby and NdYAD –> recurrence rates are high