Vitiligo

vitiligo-types pathogenesis clinical features and treatment.

1. VITILIGO Vishnu narayanan M.R.

2. EPIDERMO-MELANIN UNIT

3. MELANOGENESIS tyrosine ↓ tyrosinase DOPA ↓ tyrosinase DOPAquinone ↓ ↓ indolequinone ↓ polymerization melanin

4. CONTROL OF MELANOGENESIS Constitutional skin colour UV radiation Hormones - MSH

5. HYPOPIGMENTATION

6. MELANOPENIC HYPOPIGMENTATION

7. …VITILIGO… Vitiligo is an acquired , pigmentary anomaly of the skin characterised by depigmented white patches surrounded by a normal or a hyperpigmented border

8. The Roman physician Celsus first used the term vitiligo in the second century AD. It is interesting to note that the Rigveda (6000 BC or earlier) named leukoderma as kilas, meaning a white spotted deer.

9. ETIOPATHOGENESIS 1.GENETIC: 20 % PATIENTS- POSITIVE FAMILY HISTORY POLYGENIC INHERITANCE- NALP gene , HLADR4, CATALASE GENE, …..

10. 2. AUTO-IMMUNE HYPOTHESIS Association with other autoimmune disorders- alopecia areata and thyroid disorders Antibodies to melanocytes Lymphocytes in early lesions

11. 3. NEUROGENIC HYPOTHESIS Segmental vitiligo Nerve endings toxin destruction of melanocytes

12. Epidemiology Incidence – 1 % population Race – affects all races No sex predisposition Age – peak -10-30 years

13. Clinical features MORPHOLOGY Depigmented macules- chalky/ milky white Pigment loss- complete/ partial Macules- scalloped outline Geographical ptterns on fusion of adjacent lesions Hairs – in older lesion- leucotrichia

14. Trichome vitiligo

15. LEUCOTRICHIA

16. SITES Any part can be affected Predilection t o areas with repeated friction and trauma Dorsal aspect of hands and feets , elbows , knees

17. PATTERNS Vitiligo vulgaris Segmental vitiligo Generalised vitiligo

18. Vitiligo vulgaris Commonest type Second decade Family history Progression – rapid/slow

19. Segmental vitiligo Occurs in children Not associated with autoimmune disorders Depigmentation- dermatomal / quasidermatomal Stable course Leucotrichia Feathery margin Distant lesions- uncommon Poor response to treatment

20. Generalised vitiligo Extensive lesions

21. ACROFACIAL VITILIGO

22. LIP-TIP VITILIGO

23. VITILIGO UNIVERSALIS

24. Course Onset < 20 years Slowly progressive usually Segmental vitiligo – stable Spontaneous repigmentation - 10 – 20% Acrofacial vitiligo – resistant to treatment

25. Histology Absence of melanocyte and melanin in the epidermis e/m confirms the loss of melanocytes which appears to be replaced by langerhans cells. Increased cellularity of the dermis

26. Prognostic factors Long standing disease Leucotrichia Acro facial lesions Lesions on resistant areas Poor prognosis

27. Associations Endocrine disorders Diabetes mellitus Pernicious anemia Addison’s disease Hypoparathyroidsm Hypothyroidism Hyperthyroidism

28. Cutaneous disorders Alopecia areata

29. Halo nevus

30. Atopic dermatitis

31. Malignant melanoma

32. Morphea

33. DIAGNOSIS Age of onset Depigmented macules with scalloped borders Leucotrichia Koebner’s phenomenon Predeliction to sites of trauma

34. vitiligo albinism onset Later life At birth course Depigmentation-progress/regress Freckling on photoexposed parts Eye involvement Not seen Always present Response to treatment Partial/near complete response No response Differential diagnosis

35. Nevus achromicus Vitiligo onset At birth Not present at birth Distribution Segmental/focal Segmental/focal/ generalised Morphology Feathered margins, uniform pigment dilution Scalloped margins, islands of pigmentation Hair No leucotrichia leucotrichia

36. P iebaldism

37. LEUCODERMA All depigmented lesions Idiopathic- vitiligo Chemicals Inflammatory skin diseases

38. TREATMENT DEPENDS ON Age of patient Extent of disease Pattern of disease Cosmetic disability Effect on quality of life

39. Physical modality 1.Photochemotherapy Psoralens + UVA exposure – PUVA Mainstay of vitiligo therapy Psoralens – tricyclic furocoumarins 8- methoxypsoralen topical/systemic UVA- in special chambers containing UVA emitting tubes PUVA sol – psoralen + sunlight

40. REGIMEN Topical therapy Alternate days Systemic therapy Ointment/lotion psoralen (0.6mg/kg) gradually increasing exposure till mild erythema sunlight PUVA – UVA lamps Protect from sun for 8 hrs (11:00 - 13:00) Broad spectrum sunscreens- ZnO

41. RESPONSE TO PHOTOCHEMOTHERAPY Repigmentation - slow Begins in perifollicular area and periphery of lesion Becomes confluent Most readily on face, neck and hairy regions Slow responders – acral and non hairy parts

42. Photo-toxicity Excessive exposure to UVA / SUN Topical psoralens Treatment – withdrawal of psoralen topical corticosteroids severe – systemic steroids Nausea , vomiting, epigastric discomfort, giddiness

43. 2. Phototherapy – narrow band UVB (311nm) INDICATIONS – in extensive disease>10% indicated in children and pregnant women in patients in whom psoralens C/I REGIMEN – Gradually increasing doses of UVB, given from specialized chambers. Safe

44. Medical treatment

45. ORAL MINI PULSE

46. OTHERS

47. SURGICAL TREATMENT Indications- sites poorly responsive to conventional therapy Patient with stable disease

48. Treatment guidelines LOCALISED DISEASE New lesions Topical steroids Old lesions Topical PUVA/ PUVA sol EXTENSIVE DISEASE New lesions Oral steroids + PUVA/PUVA sol NBUVB Rapid increase Oral steroids + PUVA/PUVA sol /NBUVB Old lesions Oral PUVA/PUVA sol/NBUVB Intolerence to PUVA/NBUVB Oral steroids GENERALISED LESIONS Monobenzyl ether of hydroquinone