Copy_of_A._Vitiligo.pdf full title shown

full desceiption

1. Vitiligo
…

è Acquired localized depigmentation of skin, hair & occasionally mucosa / of unknown etiology / characterized by complete loss of melanocytes.

Definition • a circumscribed, acquired, idiopathic, progressive hypomelanosis of skin & hair which is often familial
• characterized microscopically by an absence of melanocytes.
• Leukoderma is the term applied only to depigmented patches of known causes -> as Ex:
1. following burns,
2. chemicals,
3. inflammatory disorder.
Epidemiolog
y
• Age of Onset: May begin at any age, but in 50% of cases between 10-30 years.
• Incidence: Common, worldwide. Affects up to 1% of the population.
• Equal in both sexes & All races.
Etiopathoge
nesis
1.Genetic:
• 20% patients : positive family history
• Polygenic inheritance- NALP gene, HLADR4, catalase gene, …..

2. Auto-immune hypothesis
•Association with other autoimmune disorders- alopecia areata and thyroid disorders
•Antibodies to melanocytes
•Lymphocytic infiltration in early lesions

3Neurogenic hypothesis
• It explains segmental vitiligo
•Nerve endings secrete toxins causing destruction of melanocytes.

Clinical
picture
•Vitiligo is characterized by depigmented white patches surrounded by a :
1) normal or
2) hyper-pigmented border
3) Scalloped border
• Geographical patterns on fusion of adjacent lesions
• Hairs : in older lesion become white (leucotrichia).

2. Distribution •Any part can be affected
•Predilection to areas with repeated friction and trauma
(e.g; dorsal aspect of hands and feet , elbows , knees).
•Bilateral and symmetrical.
Pattern
• Segmental vitiligo
1) Occurs in children
2) Not associated with autoimmune disorders
3) Depigmentation : dermatomal
4) Stable course
5) Leucotrichia
6) Distant lesions : uncommon
7) Poor response to treatment

•Non- segmental vitiligo

•Focal vitiligo:
one or more macules in a limited area not following a segmental
distribution.

•Trichrome vitiligo:
characterized by an intermediate zone of hypopigmentation located
between depigmented center and the peripheral unaffected skin.

•Generalized vitiligo:
widespread non segmental distribution

** Subtypes of generalized vitiligo

1) Acrofacial vitiligo:
Depigmentation on distal fingers & periorificial areas.
2) Vulgaris vitiligo:
scattered patches that are widely distributed.
3) Universal vitiligo:
Complete or nearly complete depigmentation of the body
Associations •Endocrine disorders :
1. Diabetes mellitus
2. Pernicious anemia
3. Addison’s disease
4. Hypoparathyroidism
5. Hypothyroidism & Hyperthyroidism

• Cutaneous disorders :
1. Alopecia areata
2. Atopic dermatitis

Course •Onset < 20 years
•Usually slowly progressive


• Segmental vitiligo is commonly stable
•Spontaneous repigmentation in10 – 20%
•Acrofacial vitiligo is usually resistant to treatment

3. Bad
prognostic
factors
1) Long standing disease
2) Leucotrichia
3) Acrofacial lesions
Diagnostic
work up
•Woods light examination:
milky white lesiona
•Biopsy & histopathology:
absent melanocytes
•thyroid-stimulating hormone (TSH),
•free triiodothyronine (T3),
•free thyroxine (T4) levels
•Antinuclear antibody
•Antithyroid peroxidase antibody
•CBC count with differential
Physical
modalities
1.Photo-chemotherapy
• Psoralens + UVA exposure = PUVA
• Psoralens (topical/systemic): tricyclic furocoumarins, 8- methoxypsoralen
•UVA: in special capinets containing UVA emitting tubes.
•PUVA sol: psoralen + sunlight(11:00 - 13:00)
# Regimen :
Topical therapy (Ointment/lotion ) or Systemic therapy (psoralen 0.6mg/kg) then UVA exposure after 15 min of topical or 2 hours of oral psolaren
Gradually increasing exposure till mild erythema occurs.
Protect from sunlight for 8 hrs
Broad spectrum sunscreens
# Response :
• slow repigmentation
• Begins in perifollicular area and periphery of lesion
• Becomes confluent

2. Phototherapy-narrow band UVB (311nm)
# Indications :
1. extensive disease>10%
2. children & pregnant women
3 patients in whom psoralens is contraindicated
# Regimen :
1. Gradually increasing doses of UVB,
2. given from specialized chambers,
3. no psolaren.
# Safety: Safe with minimal side effects

4. Medical
Treatment
1] Topical steroids’ indications :
1) single lesion especially new
2) Adjuvant to other lines of treatment

2] Systemic steroids’ indications :
1) Patient can’t be given physical modalities
2) Rapidly progressive vitiligo with phototherapy
3) Vitiligo unresponsive to psoralens

3] Calcineurin inhibitor (tacrolimus, pimecrolimus): for facial lesion

4] Depigmenting agent to depigment resirual areas of normal skin in universal vitiligo: monobenzyl ether of hydroquine
Treatment
guidelines
•LOCALIZED DISEASE
1) New lesions: Topical steroids
2) Old lesions: Topical PUVA/ PUVA solution

•EXTENSIVE DISEASE
1) New lesions: Oral steroids + PUVA/PUVA solution, NBUVB
2) Rapid increase: Oral steroids + PUVA/PUVA solution, NBUVB
3) Old lesions: Oral PUVA/PUVA sol/ NBUVB
4) Intolerance to PUVA/NBUVB: Oral steroids

•GENERALIZED LESIONS
*Depigmentation by Monobenzyl ether of hydroquinone

Surgical
treatment
•Indications:
sites poorly responsive to conventional therapy

#Ex. In Patient with stable disease
1.transfer of Melanocyte
2. grafting of ;
a) Blister
b) Punch
c) Split thickness skin