Skin colour disorders Dan Flashcards
What is Laugier-Hunziker Syndrome?
Rare acquired lentiginosis syndrome onset in adulthood, benign cause unknown
Macular pigmentation of lips and buccal mucosa, palms and soles
Longitudinal black melanonychia
No systemic associations, good prognosis
DD for Peutz-Jeghers
What is Fanconi’s anaemia?
rare AR disease
M>F,
onset at 4-10 years can present to haem or derm
generalised mottled dyspigmentation of skin w/ CALMs and depigmented raindrop macules
mucosa spared
dysmorphism may be mild includes triangular facies, microcephaly, aplasia of thumbs or radii, cardiac or renal malformation
develop hypoplastic anaemia, low plts and low neuts
acute leukaemia risk - poor prognosis
What is Cronkhite-Canada syndrome?
rare condition of unknown aetiology middle aged, often japanese twice as common in men malabsorption w/ abdo pain and diarrhoea lentigines on limbs and face and can be hyerpigmentation on acral areas or generalised nail dystrophy alopecia - patchy then total Investigate and treat malabsorption
What is ochronosis?
Pigmentation of the skin, bone and cartilage that is ochre-coloured (yellow) under microsocope but blue-black to the naked eye
Caused by AR alkaptonuria or exogenous causes;- oral quinine or quinacrine- topical hydroxyquinone or phenol
Alkaptonuria causes;
back and joint pain
pigmented sclerae and skin
black sweat and cerumen, urine turns black on standing
athersclerosis
SOB due to resp tract deposits
Test urinary homogentisic acid
Rx low protein diet vitamin C
supportive Rx of complications
What are the causes of congenital depigmentation/ hypopigmentation?
Generalised: • Oculocutaneous albinism (OCA) - Hermansky-Pudlak - Chediak-Higashi - Cross Syndrome • Albinoidism • Albinism-deafness syndrome • Griscelli syndrome and Elejalde syndrome • Menke’s disease • PKU • Homocystinuria • Histidineamia • Ectodermal dysplasia • Sialic acid storage disease • Apert’s syndrome • Vitiligo (rarely generalized) Macular: • TSC (ash-leaf/hypopigmented macules) • Piebaldism • Waardenburg’s syndrome • congenital vitiligo • Dyschromic amyloidosis (guttate leukoderma) • Naevus depigmentosus • Naevus aneamicus (vasc not pigment) Blaschkoid/Linear: • Linear and whorled hypopigmenation • Hypomelanosis of Ito • Focal dermal hypoplasia • segmental vitiligo • Segmental Ash-leaf/hypomelanotic macule • Female Menkes carrier • Conradi Hunermann • epidermal naevus • Pigmentary demarcation lines (type C)
What are the causes of localised (scalp) poliosis?
Idiopathic Inflammatory or autoimmune • Vitiligo • Halo nevus or melanoma • Alopecia areata • Postinflammatory (e.g. DLE) • Post-traumatic • Vogt-Koyangi-Harada (eye) syndrome Inherited • TSC hypomelanotic macule • Piebaldism (midline frontal) • Waardenburg syndrome • Isolated white forelock Nevoid • Associated with nevus comedonicus • Angora hair nevus • Scalp heterochromia secondary to mosaicism
What is hypomelanosis of Ito?
Neurocutaneous disorder due to mosaicism of pigment cells causing hypopigmentation in streaks and whorls in Blaschko’s lines
- uni or bilateral, trunk and limbs, assymetrical, spares acral surfaces and scalp
Starts as small macules in early infancy and spreads
30-50% have associated abnormalities
- CNS (neurocuatneous) + ITO
CNS (Seizures, mental or motor retardation, microcephaly, hypotonia, hyperkinesias, deafness, ataxia)
I = eyes (Ptosis, non-closure of upper lid, symblepharon, dacryostenosis, strabismus, nystagmus, corneal opacification, cataracts, myopia, amblyopia, micropathalmia, iridal heterochromia, scleral melanosis, patchy hypopigmented fundi)
T = teeth (dental enamel changes)
O = osteo (bones) (Short stature, pectus carinatum, scoliosis, polydactyly, clinodactyly, asymmetry of limb & face) Geentic counselling, camouflage
What are the associations of vitiligo?
'Type 2 TRAMP' T2DM Thyroid Dx (hyper/Hypo) 25% RA Alopecia areata, Addison's Dx Morphoea or Lichen sclerosus Pernicious anaemia
V. rare;
APECED syndrome
What are the risk factors for progressive vitiligo?
Non-segmental vitiligo
Mucosal involvement
Family Hx
Koebnerisation
What are the good prognostic markers for Rx response in vitiligo?
Younger patients
Recent onset disease
Darker skin types
Lesions on face, neck, and trunk
What are criteria for surgical Rx of vitiligo?
stable vitiligo for at least six months unsatisfactory response to medical rx absence of Keobnerisation no tendency to scar/ keloid age > 12y positive mini-grafting test (small punch grafts 1-2mm taken from uninvolved skin are implanted within acrhomic areas separted from each other by 5-8mm)
What is the aetiology of vitiligo?
complex multifactorial not fully understood
likely genetic and environmental factors
3 current theories;
1. Autoimmune disease (assoc w other AIDxs)
2. Neurogenic hypothesis (toxins released from skin nerve endings inhibit and destroy melanocytes)
3. Self-destruct theory of Lerner - melanocytes cannot metabolise a toxic melanin precursor so self-destruct
What is the classification and clinical types of vitiligo?
Classification;
Localized;
- Focal
- Segmental - 10% of cases but 30% in kids, 50% in trigemminal area, 50% have poliosis; stable, AIDx unlikely
- Mucoasal (genital)
Generalized;
- Vulgaris (most common; scattered patches that are widely distributed)
- Acrofacial
- Universal - >80% skin, rare, high AIDx assoc
- Mixed e.g. acrofacial+vulgaris and/or segmental
Clinical types;
Classical - milk white, convex border, expands centrifugaly
Ponctue - confetti like
Inflammatory - raised, erythematous border
Blue - vitiligo in area of post inflam hyperpigmentation (isotopic response)
Trichrome - Vitiligo/hypopigmented zone/normal skin
Quadrichrome - as tricrome + dark brown perifollicular in vitiligo areas which are repigmenting
Pentachrome - vitiligo, normal skin and 3 intermediete shades of brown reproted in type 5 skin
What are the types of melasma?
Types - Centrofacial (most common) (forehead, cheeks, nose, upper lip – sparing philtrum, and chin) - Malar (cheeks and nose) - Mandibular (along jawline) Overlap of these is most common
What is vitiligo treatment ladder?
General Sunscreen very important Camouflage - cosmetics, fake tans Address psychosocial issues Specific Potent TCS 1st line Topical tacro 1st line in kids and good for adults, can also use pimecrolimus e.g kids UVB if failed topicals or >15% BSA; start 50 mJ/cm2 with 10-20% increments @ 2-3 x weekly until sufficient erythema is achieved within lesions and stay in that dose.Can add oral Vit E for better effectUVB + afamelanotide 16mg S/C for better effect esp in SPT 4-6 (2015 paper-remember!) 308nm Excimer laser +/- TCS or TCNI Topical or systemic PUVA (5MOP 1st line but often not available, 8MOP 2nd line but usually used) 2/3 line calcipotriol - adjunt to TCS Surgery - Blister grafting - punch grafting - split skin grafting - melanocyte suspension technique Depigmentation - if extensive unresponsive disease - Monobenzyl ether of hydroquinone (MBEH) 20% cream, up to 40% for stubborn areas - QS Ruby or Alexandrite laser
