vitiligo presentation .pptx TOPIC VITILGO IN

VITILIGO

1. VITILIGO Presented by- Dr. Krishan Kumar Jat MD Scholar Department of Roga Nidana Evam Vikriti Vigyana

2. Skin color Mostly determined by various amounts of melanin: Produced by melanocytes in stratum basale . Composed of two molecules of amino acid tyrosine; chemically bonded by series of reactions catalyzed by enzyme tyrosinase; occurs in stepwise fashion within special vesicle (melanosome). Primary function - Protecting keratinocyte DNA from mutations induced by UV radiation. Melanocyte's arm-like extensions contact or even pierce plasma membranes of keratinocytes in stratum basale and spinosum. Melanosomes migrate to ends of extensions; released by exocytosis; taken into cytoplasm of keratinocytes. Transported to superficial side of nucleus (faces exterior of body); shields DNA like umbrella. Must be produced continuously to maintain consistent skin color; degrades after a few days

3. Melanocytes and melanin function

4. Melanin UV radiation has both immediate and delayed effects on skin pigmentation : Amount of UV radiation melanin can absorb is limited as is the protection provided. People of all skin pigmentations can develop sunburns and are at risk for skin cancers. Secondary function of melanin - Reduces synthesis of vitamin D in response to UV radiation; leads to less calcium ion absorption and maintenance of calcium ion homeostasis within narrow range: Individuals living in regions exposed to high amounts of UV radiation (Africa) developed darker skin to prevent excess vitamin D production. People in areas with less UV radiation (northern Europe) developed lighter skin so they could synthesize enough vitamin D.

5. Melanin Skin color depends on number of melanocytes in particular body region: Differences lead to uneven distribution of melanin; fewer melanocytes on palms of hand and soles of feet, for example Overall number of melanocytes is virtually identical among all individuals, irrespective of skin color Spectrum of human skin tones is due to differences in amount of tyrosinase activity and type (color) of melanin produced.

6. Cont. Common variations of pigmentation: Freckle - small area of increased pigmentation; increased melanin production in local spot. Mole or nevus - area of increased pigmentation, caused by local proliferation of melanocytes; not an increase in melanin production. Albinism - melanocytes fail to manufacture tyrosinase; results in lack of skin pigmentation and greatly increased risk of keratinocyte DNA damage from UV radiation

7. Carotene and Hemoglobin Two minor pigments have effect on skin pigmentation: Carotene - Yellow-orange pigment in food items such as egg yolks and orange vegetables. Lipid-soluble molecule; acoumulates in stratum corneum. Imparts slight yellow-orange color; particularly visible in stratum corneum of thick skin. Hemoglobin - in red blood cells; iron-containing protein; binds to and transports oxygen throughout body: Oxygen binds to iron in hemoglobin in oxidation reaction; same reaction causes iron to rust; oxidized hemoglobin changes color to bright orange-red; gives blood characteristic color. Hemoglobin's effect on skin color is indirect result of blood flow in dermis; color of blood in deeper dermis is visible through epidermis.

8. Skin Color as a Diagnostic Tool Color changes associated with amount of blood flow in dermis can be useful in diagnosis of disease: Erythema - blood flow in dermis increases; makes skin more reddish. Normal response to exercise; blood flow in dermis increased to maximize heat released to external environment. Other conditions causing erythema include trauma, fever, and infection. Pallor - blood flow in dermis decreases; results in loss of normal pinkish hue; most visible in pale-skinned individuals; epidermis takes on whitish color of collagen in dermis. Normal response when body is conserving heat in cold environment. Can also occur when nervous and endocrine systems alter blood flow to dermis; part of flight or fight response. Cyanosis - sign that someone needs immediate attention; hemoglobin has very low levels of bound oxygen; blood turns reddish purple; skin takes on faint bluish hue; can occur when; Someone has difficulty breathing. Hemoglobin or red cell levels are low in blood. Hemoglobin is unable to bind to oxygen.

9. Pathogenesis of Hypopigmentation Hypopigmentation of skin is of two types: 1.Melanopenic Hypopigmentation: Decrease in number of melanosomes and can be due to- a) Anatomical defect of melanocytes- Absent/damaged melanocytes- e.g. Vitiligo, Piebaldism , Chemicals like rubber, Postinflammatory . b) Functional defect of melanocytes- Defective tyrosine metabolism e.g. Pityriasis versicolor, Endocrine disorders, Albinism. 2.Non-Melanopenic Hypopigmentation : Due to abnormalities of vasculature, e.g. nevus anemicus .

10. Definition Vitiligo - An acquired de-pigmenting disorder of unknown etiology. It is a chronic skin disease, characterized by the appearance of white depigmented macules and patches. It is characterized microscopically by absence of melanocytes. It is not a harmful disease. Causes psychological problems like tension, embarrassment or loss of self-confidence.

11. Etiology Exact mechanism is not known. The main causes of this disease are inheritance and mental or physical trauma. 1. Genetic hypothesis- Genetic factors definitely important, since 20% of patients have a positive family history. 2. Autoimmune hypothesis- Evidence pointing to autoimmune etiology includes; Frequent association with other autoimmune disorders like alopecia areata and thyroid disorders. Presence of antibodies to melanocytes. Presence of lymphocytes in early lesions.

12. Epidemiology Incidence: affects 1-2% of the world's population. Affects all races. Gender: No gender predilection. Age: Affects all ages; peak incidence between 10 and 30 years. 3. Neurogenic Hypothesis- Segmental vitiligo is present along a dermatome in distribution of nerves, suggesting a neurogenic origin. It has been hypothesized that a toxin, which destroys melanocytes, is released at the nerve endings. immediate mechanism for the evolving white macules involves progressive destruction of selected melanocytes by cytotoxic T cells.

13. Clinical presentation Morphology- Depigmented macules, which are chalky or milky white. Sometimes, pigment loss is partial and occasionally, three shades (trichrome) are seen in the same lesion-depigmented center, surrounded by a hypopigmented rim, which in turn has normal pigmented skin around it- represents different stages in the evolution. Macules have a scalloped (wavy) outline and form geographical patterns on fusion with neighboring lesions. Hairs in the lesions may remain pigmented, though in the older lesions the hairs may lose their pigment ( leucotrichia ). Sites- Lesions Can occur in any part of the body. Areas subjected to repeated friction and trauma are frequently affected, e.g. the dorsal aspect of hands and feets ,elbows and knees.

14. Patterns- 1.Vitiligo vulgaris- Commonest type. Scattered pattern & Widely distributed. Occurs after second decade. May be slowly or rapidly progressive. Family history is frequently present.

15. 2. Segmental vitiligo- Unilateral and asymmetric in distribution. Only one side of the body is affected. Common in children. Most frequently (50%) seen in distribution of trigeminal nerve (mandibular division). Has a stable course i.e. lesions increase initially (6-12 months) and then remain static. Leucotrichia on the depigmented areas as well as away from vitiliginous areas frequently seen. Margins are feathery. Distant lesions are uncommon. Poor response to treatment. Not associated with an autoimmune disease.

16. 3. Generalized vitiligo- Extensive lesions. Variants of generalized vitiligo are: a) Acrofacial vitiligo- Vitiligo predominantly seen periorificially (around eyes and on lips on the face) and acral parts ( periungual area i.e fingernails or toenails, palms, and soles). This type of vitiligo is more resistant to therapy due to absence of hair in the affected parts.

17. b) Lip-tip vitiligo- When lips, tip of penis, the vulva and nipples are involved. c) Vitiligo universalis- Widespread vitiligo with only few areas of normal pigmentation.(Nearly complete depigmentation) This type of vitiligo is often associated with multiple Endocrinopathies.

18. Associations Cutaneous disorders : Alopecia areata, halo nevus, atopic dermatitis, malignant melanoma, and morphea. Endocrine disorders : Diabetes mellitus, pernicious anemia, Addison's disease, hypoparathyroidism, hypothyroidism, and hyperthyroidism.

19. Course Onset usually before age of 20 years. Usually slowly progressive, but sometimes can progress rapidly. Segmental vitiligo progresses initially but stabilizes in about 6 months Spontaneous repigmentation is seen in 30% of patients, especially in the sun-exposed parts. Acrofacial vitiligo is more resistant to treatment.

20. Prognostic factors Following factors indicate poor response to treatment: Long-standing disease. Leucotrichia . Acrofacial lesions. Lesions on resistant areas, i.e., bony prominences, non-fleshy areas, non-hairy areas and mucosae, and on ankles, wrists, elbows, periungual areas, nipples and areolae lips, and genitalia.

21. Differential diagnosis 1.Albinism- An inherited condition that leads to someone having very light skin, hair, and eyes. Caused by mutations of certain genes that affect the production of melanin. 2.Piebaldism- It is autosomal dominant disorder affecting melanocyte migration and development. Charecterized by isolated congenital leukoderma and poliosis (white hair) in a distinct ventral midline pattern.

22. 3.Nevus achromicus - A sporadic defect in the embryonic development. Distribution is also fairly stable and are nonprogressive hypopigmented patches. 4.Leucoderma- It is an acquired condition with localized loss of pigmentation of the skin that may occur after any number of inflammatory skin conditions, burns, intralesional steroid injections, postdermabrasion, etc. Leucoderma is a term which includes all depigmented (white) lesions of skin including vitiligo.

23. Investigations 1) Wood lamp examination 2) Dermatopathology - Skin Biopsy- Shows normal skin except for absent melanocytes. Special stain is used to identify melanocyte. 3) Electron microscopy- absence of melanocytes and melanosome in keratinocytes. 4) Lab studies- Thyroid profile, Fasting blood glucose, CBC with indices(pernicious anemia), ACTH stimulation test(Addison disease suspected).

24. Management General Measures- Reassurance and psychological support to the patient and family. Explanation about prognosis. Treatment depends on- Age of patient. Extent of disease. Pattern of disease. Cosmetic disability. Effect on quality of life

25. Physical modalities of treatment 1.Photochemotherapy- Photo-chemotherapy is use of psoralens in combination with UVA exposure(PUVA). It forms the mainstay of therapy in vitiligo. Repigmetation is slow. 2.Phototherapy- a) Broadband UVB : Is no longer used. b) Narrow band UVB (311 nm): Indications: In extensive disease (>10%). Especially indicated in children and in pregnant women and in patients in whom psoralens are contraindicated. Side effects: generally safe. Produces best results in the face.

26. Medical treatment 1. Steroids- Topical steroids: Are used for: Single lesions, (sometimes a few localized lesions) especially of recent origin. As adjuvant to other forms of therapy. Systemic steroids: Are used: When the patient cannot be given photo-therapy/photochemotherapy. In rapidly progressive vitiligo, along with PUVA/PUVA sol. In vitiligo, unresponsive to psoralens. Side effects to steroids limit their use, though the recently devised weekly schedule (oral mini pulse) probably causes fewer side effects than daily doses. 2. Topical calcineurin inhibitors- Tacrolimus and Pimecrolimus. Effective in repigmenting vitiligo but only in sun-exposed areas. Reported to be most effective when combined with UVB or excimer laser therapy.

27. 3. Depigmenting agents: Like monobenzvl ether of hydroquinone. Used to depigment the few normally pigmented areas in patients with extensive vitiligo. Depigmented skin of photo-exposed areas aggressively protected with sunscreens to prevent spotty repigmentation

28. Surgical measures Indications: At sites poorly responsive to conventional therapy (ankles and knuckles), in a patient with stable disease (for at least 6 months). Techniques: Melanocyte transfer. Blister grafting. Punch grafting. Split thickness skin grafting

29. Facts 1.Vitiligo is a condition which affects the skin's pigmentation and results in loss of the normal skin color. 2. Vitiligo affects people of all races. 3. Around 1/3 of patients with vitiligo have family members with the same condition. 4. The average age of onset of vitiligo is 20 years. 5. The specific causes of vitiligo are unknown. 6. But, vitiligo is thought to be caused by an autoimmune process which destroys the melanocytes. 7. Symptoms of vitiligo include patches of skin which have become lighter than the surrounding areas. 8. The white spots on the skin of vitiligo are usually not itchy or scaly. 9. Sun exposed areas such as the face and hands and feet are usually the first ones to loose their color. 10. Vitiligo also develops at the sites of trauma such as cuts. This is called the Koebner phenomenon.

30. THANK YOU A black dot on white skin is a BLESSING, whereas a white dot on black skin is a BLEMISH.