Simple notes in vitilgo

definition....
acquired areas of depigmentation

Causes....[actually no known causes but hypothesis]
1-)autoimmune hypothesis:
*autoimmune destruction of cutanous melanocytes with total loss of melanocytes on the affected area of skin.
*lymphocytic infiltration on skin biopsy indicate involvement of lymphocytes in the destruction process.
*may associated with other autoimmune diseases [alopecia areata, thyroid dysfunction, Addison disease, adrenal disease, atrophic gastritis, perncious anemia].
*serum autoimmune antibody against melanocytes , thyroid, adrenal, gastric parital cell or intrinsic factor.


2-)self destruct hypothesis:
*defect in the natural protect mechanism of melanocytes.
*this defect will cause accumulation of toxins procusers which destroy melanocytes.


3-)neurgenic hypothesis:
*caused from released compound at the peripheral nerve endings in the skin which is toxic to the melancytes.
*the affected areas shows sympathatic nreve dysfunction.

Note:[vitilgo also may be caused as a result of truma , cauld be familial etheir]


Clinical presentation:

+distribution:
-localized disease in---
*sun exposed areas[dorsal of hands]
*normal hyperpigmented areas[axilla,groin,
nipple, flexures]
*sites of friction[bony promenince]

-generilized--- widspread disease.
+lesions:
*typical presentation=white milky colouration ,sharp
margin ,no scales , normal texture & intact sensation
*Atypical presentation=
-trichome\\ tan colour naturally evolves typical area
-quadrichrome\\perifollicular macules or repigmented
vitiligo.
-inflammatory\\erythomatous .
+differential diagnosis of vitiligo:
*generalized hypomelanosis[albinism-hypopitutrism]
*patchy hypomelanosis[vitiligo-sclerosis]
*inflammed patchy hypomelanosis[tinea versicolor-leprosy-
pityriasis alba].
*atrophied patchy hypomelanosis[morphea-post inflamm.-
lichen planus].
+investagation:
-skin biopsy:absent melanocytes.
-wood's lamp:ivory white skin lesions.

Treatment:

1)sun screens[spf more than 30]
what for?..1.vitiligous ares are more suscptable for sunburn.
2.sunburn to normal skin may turn into vitiligo[kobner phenomena]
3.in vitiligous area sun induced darkening of the surrounding
normal skin cause accentuation of cosmatic disfigurment.

2)camouflage=covermark=dermablend
what for?... it's a tanning preperation contain Dihydroxy acetone.

3)Repigmentation therpies for localized vitiligo
1-topical corticosteroid=sicorten[0.5% halometasone]
*twice dialy to 6-12months[should stoped if no improvement]
*once dialy in flexural area.
*shouldn't applied to eyelids or periorbital areas for risk of
cataract or glucoma.
2-PUVA(psoralen ultraviolet radiation A)
*the treatment 2 times per week & it needs to avoid sunlight 2 days
after each session with using of sunsceens outdoor.
*ultraviolt A radiation for 30 minutes after application of
meladinine[methoxasalen]
*the PUVA cotinued for 1 year [100-200session]
*contraindication for PUVA:
-pregnant women
-children below 12
-photosensetivity
-cardiac diseases
-hepatic diseases
-renal diseases
-visual problem[aphakia- cataract]
-skin cancer
4)depigmentation therapy
*by using bleaching agents 20% hydroqunine(benzoquine) one or
twice daily when the vitiligo is extensive or universal.
*side effect: dermatitis-albinoid skin



the fate of vitilgo:
stasis ~ spread ~ re pigmentation spontaneously