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Pigmentary disorders of skin, leukoderma


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Dr. Angelo Smith M.D WHPL VITILIGO

Melanocytes and melanin:

Melanocytes are special cells in our skin that specialize in making a molecule called melanin. What is Melanin? Melanin is something called a pigment, which is the molecule that gives our skin colour a darker shade. Melanocytes and melanin

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What does melanin actually do? Melanin protects our skin from the damaging Ultraviolet (UV) rays from the sun. Going sun tanning induces your body to produce more melanin, which is why people who return from tanning look darker. More melanin in the skin is the reason why people who are darker usually do not get sunburned.


MELANOGENESIS Melanoblast Melanocyte Melanin Phenylalanine  Tyrosine Color of the Race  Rate of melanin production.

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In our skin, we all have around the same number of melanocytes, which are the cells that produce melanin. However, the melanocytes in each of our bodies produce different amounts of melanin. The more melanin you have in your skin, the darker your skin color will be.


Facts Origin of word Vitium Vitellius Can appear at any age, usually first appears between the ages of 20 and 30 White patches may begin on your face above your eyes or on your neck, armpits, elbows, genitals, hands or knees 1-200 of the world population develops Affects both genders and all races equally

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It is a skin condition that can manifest after birth at any point in someone’s life. It leads to death or loss of function of the melanocytes in the body, which leads to the inability to produce any more melanin in the skin. Vitiligo is very visible on someone with a very dark complexion due to the prevalence of white splotches of skin.

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Chronic skin disease Other name = Leukoderma White spots occur when the skin no longer forms melanin (pigment that determines the color of your skin, hair, and eyes) The white patches of irregular shapes begin to appear on your skin

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Any part of the body may be affected. Common sites are exposed areas (face, neck, eyes, nostrils, nipples, navel, genitalia), body folds (armpits, groin), sites of injury (cuts, scrapes, burns) and around pigmented moles ( halo naevi )

Symptoms & Signs:

Symptoms & Signs White patches of skin Whitening or graying of the hair on your scalp, eyelashes, eyebrows or beard ( leukotichia – seen in segmental) Loss of color in the tissues that line the inside of your mouth Loss or change in color of the inner layer of your eye

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The degree of pigment loss can vary within each vitiligo patch which means that there may be different shades of brown in a vitiligo patch. This is called ‘ trichrome ’. A border of darker skin may circle an area of light skin.


ASSOCIATIONS Premature graying of hairs in relatives. Koebner phenomenon. Emotional or Physical stress. Drugs  Chloroquine and Clofazimine .


SYSTEMIC ASSOCIATIONS  risk of Autoimmune diseases.  Thyroid dis. [Hashimoto’s, Grave’s]  Addison’s disease  Pernicious Anemia  Insulin dependent Diabetes  Alopecia Areata


SYSTEMIC ASSOCIATIONS Eye disorders  Uvietis  Depigmentation of Choroid. Ear disorders  Auditory problems


PSYCHOLOGICAL IMPACT Feelings of stress, embarrassment and self consciousness. Perception of discrimination. Low self esteem . Disturbed sexual relationships.


ETIOLOGICAL THEORIES Familial Theory Auto-immune Theory Autocytotoxic Theory Neural Theory Self destruction Theory


FAMILIAL THEORY Epidemilogically , 25 - 33% have family members with disease. Close biologic relatives  4 - 5 folds increased risk. HLA studies have variable results. No specific genetic pattern.


AUTO-IMMUNE THEORY Antibodies against melanocyte surface antigens, correlate with the extent of depigmentation. Antityrosinase ab., Antimelanin ab. and melanin-sensitized lymphocytes. Leukocyte migration inhibition factor levels and circulating immune complex levels markedly elevated.


AUTOCYTOTOXIC THEORY Increased melanocyte activity, leads to its own demise. Inhibition of Thioredoxin reductase , by Calcium. Higher Ca levels cause  superoxide radicle formation. Levels of Catalase , markedly decreased.


NEURAL THEORY Based on the following observations:  Patients with nerve injury and vitiligo in denervated areas .  Clinical evidence of segmental dermatomal vitiligo.  Increased sweating and vasoconstriction in vitiliginous areas.


NEURAL THEORY… [CONT.] Depigmentation in animal models with severed nerve fibres . Degenerative and regenerative autonomic nerves in depigmented patches. Increased urinary excretion of VMA and HVA in active vitiligo.


It suggests that melanocytes are destroyed by flaws in the protective mechanism that removes the chemical toxins that is generated in melanogenesis. SELF DESTRUCTION THEORY

Medical Screenings::

Medical Screenings : A family history of vitiligo Look to see if there is a rash, sunburn, or other skin trauma that has occurred within 2 or 3 months after pigmentation was discovered Premature graying of the hair (before age 35) Stress or physical illness Also they may ask for an eye examination (inflammation of your eye) and/or blood test (autoimmune disease)


HISTOPATHOLOGY Uniform absence of Melanocytes. Periphery of depigmented patch show : signs of cellular death. Dilatation of rough endoplasmic reticulum in melanocytes. Inflammatory changes in dermis.


EVALUATION Total body Wood’s light examination. TSH levels [Thyroid disease]. CBC [Pernicious anemia]. Evaluation about Diabetes Mellitus. Ophthalmological examination.


TREATMENT 1. Cosmetic 2. PUVA a. Topical b. Systemic 3. Corticosteroids 4. Surgical Treatment 5. Monobenzyl ether of Hydroquinone


COSMETIC TREATMENT Patches on exposed parts can be concealed by:  Make up brands : Cover Mark, Derma blend, Derma color etc.  Topical dyes : Clinique bronze gel, Vitadye , Dyoderm etc. Tanning creams : Chromelin , self tanning milk etc . Advantages:  Cost, ease of application, lack of side effects. Disadvantages:  Vigorous physical activities and in extensive disease.

P U V A:

P U V A Historically, Egyptians in 13th century  The herb “ Ammi majus linnaeus ”  Ammoidin  8-MOP, 5-MOP and 8-isoamylene OP 1904, Montgomery, Light therapy in vitiligo 1948, Al- Moftey , First use of light therapy in combination with psoralens .


MECHANISM OF ACTION [PUVA] Immunologically mediated action. Stimulation of tyrosinase activity. Inhibition of DNA and protein synthesis. Depletion of EGF expression. Depletion of vitiligo - associated melanocyte antigens.


MELANOCYTE REPIGMENTATION Activation of inactive cells [spared in vitiligo process] in the middle and lower part of follicle and in outer sheath. These inactive cells contain structural and melanosomal proteins, but do not contain enzymes, required for melanogenesis.


MELANOCYTE REPIGM. [CONT.] Migration of melanocyte from lower hair follicle to epidermis, depends on : a ) Cytokine release , like FGF, IL-1, b ) Inflammatory mediators such as : TGF-  , leukotriene C 4 , D 4 , and endothelin-1.


TOPICAL PSORALENS Patients with less than 20% of total body surface. Initially 0.05% or 0.1% strength. Artificial UVA source for 30 seconds initially and increasing exposure to up to10 minutes 2 - 3 times per week. At 10 minutes, higher strength (0.1% to 0.15%) prescribed.


TOPICAL PSORALENS (CONT.) Shielding uninvolved skin and eyes. Wash off the topical solution immediately after treatment. Sun blocks, Avoiding direct and filtered sunlight for the rest of the day. Side effects  Blistering, Burning and Perilesional hyperpigmentation.

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Most effective treatment available PUVA therapy is to repigment the white patches time-consuming, and care must be taken to avoid side effects Psoralen is a drug that contains chemicals that react with ultraviolet light to cause darkening of the skin. Psoralen is injected orally or is applied to the skin Then skin is carefully timed exposure to sunlight or to ultraviolet A (UVA) light that comes from a special lamp .


ORAL PSORALEN / UVA Patients with extensive disease. 0.5 mg / kg, 2 hours before treatment. Started at 1-2 j / cm 2 of light 2 - 3 times a week . Darker pigmented patients and children respond better to PUVA.


ORAL PSORALEN / UVA Trunk, proximal extremities and face respond better to PUVA. Distal extremities, periorificial and dermatomal lesions do not respond better. Side effects  burns, nausea, erythema, pruritus, xerosis , fatigue, carcinogenecity , pigmentation, cataracts and aging.


ORAL PSORALEN / UVA Contraindicated in  Pregnant women, breast feeding, h/o skin cancer, arsenic exposure, photosensitivity, radiotherapy, and cataracts. Advised to  Visit Ophthalmologist yearly, wear goggles, avoid direct and filtered sunlight for 24 hours after treatment.


CORTICOSTEROIDS First used in 1959 by Japanese. Both systemic and oral. Localized depigmented patches. High potency steroids for 1 - 2 months. Slowly tapered to lower strength. Usual side effects.

Topical steroid therapy:

Topical steroid therapy The use of steroid creams may be helpful in returning the color to the white patches A mild topical corticosteroid cream for children under 10 years old and a stronger one for adults Cream must be applied to the white patches on the skin for at least 3 months before seeing any results Corticosteroid creams are the simplest and safest treatment for vitiligo, but are not as effective as psoralen photo chemotherapy SIDE EFFECTS occur in areas where the skin is thin, such as on the face and armpits, or in the genital region They can be minimized by using weaker formulations of steroid creams in these areas.


SURGICAL MODALITIES Localized non-progressive patch in a non- acral location. Epidermal grafting Autologous minigrafting Transplantation of in vitro-cultured epidermis. Transplantation of non-cultured melanocytes.


EPIDERMAL GRAFTING Blisters at donor and recipient sites by suction or liquid nitrogen. Roof of the blister is removed from both sites and donor epidermis is placed on denuded recipient site. Reinforcement with biological dressing . Repigmentation seen in 2 weeks to 3 months. Pre-treating donor site with topical PUVA, to stimulate melanogenesis, may enhance re-pigmentation. Low incidence of scarring.


AUTOLOGOUS MINIGRAFTING Multiple small punch biopsy specimens. At Inconspicuous donor site, close together. At recipient site, separated by 4 - 5 mm. Test area chosen and 3 - 5 minigrafts are placed to determine the ability. After 2 months, if the pigment has spread, grafting of the entire region continued.


IN VITRO CULTURED EPIDERMIS Blisters at both donor and recipient sites. Epidermis from donor site is treated with trypsin. Melanocytes isolated and grown in cell culture for 3 weeks. Melanocytes adhere to Vaseline gauze, which is divided, and placed over the denuded recipient site.


IN VITRO CULTURED EPIDERMIS With this procedure, repigmented site can be as large as 10 times the donor site. Pitfalls of this technique : 1. Variegated color, due to variable melanocyte concentration on the gauze. 2. Spotty graft failure


NON CULTURED MELANOCYTES Non cultured melanocytes obtained with dermatome from donor site. Melanocytes treated with trypsin, EDTA, and placed in a saline solution. Injected as suspension into blisters in the recipient site created by liquid nitrogen. Repigmentation is faster than in vitro melanocytes.


HYDROQUINONES Used in extensive disease where, remaining normal skin is depigmented. Inhibit tyrosinase , Decrease the number of melanized melanosome , Alter melanosomal configuration, and Cause melanocyte organelle disuption and lysis . Results may take from one month to one year, to depigment completely.


Vitiligo frequently begins with a rapid loss of pigment which may be followed by a lengthy period when the skin color does not change. Later , the pigment loss may begin again. The loss of color may continue until, for unknown reasons, the process stops. Cycles of pigment loss followed by periods of stability may continue indefinitely. PROGNOSIS

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