Vitiligo

DERMATOLOGY

1. VITILIGO By Mwachibua Sam 5 th Year MBchB(MKU)

2. …Vitiligo… Vitiligo is an acquired, pigmentary anomaly of the skin characterized by depigmented patches surrounded by a normal or hyperpigmented border.

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

4. ETIOPATHOGENESIS 1. GENETIC: 20% patients – positive family history POLYGENIC INHERITANCE – NALP gene, HLADR4, CATALASE GENE

5. 2. AUTO – IMMUNE HYPOTHESIS Associated with other autoimmune disorders eg alopecia areata and thyroid disorders. Antibodies to melanocytes Lymphocytes in early lesions

6. NEUROGENIC HYPOTHESIS Segmental vitiligo Nerve endings produce toxins which cause destruction to melanocytes.

7. Clinical features MORPHOLOGY Depigmented macules – chalky/ milky white. Pigment loss – complete / partial Geographical on fusion of the adjacent lesions Hairs – in older lesions - leucotrichia

8. PATTERNS SEGMENTAL VITILIGO Manifest as one or more macules that follow the lines of BLASCHKO/ dermatomal It is unilateral and does not cross the midline. Occurs most in children. Not associated with autoimmune disorders. Feathery margin. Leucotrichia.

9. Non – segmental Vitiligo Includes all types of vitiligo that cannot be classified as segmental. Associated with markers of autoimmune or inflammation such as halo nevi and thyroid antibodies. Non segmental vitiligo include: Focal- Xtd by one or more macules in a limited area&do not follow segmental distribution. Generalize-Follows a non-segmental distribution and is more widespread than focal.

10. Subtypes of generalized vitiligo 1. Acrofacial vitiligo- Depigmentation occurs on the distal fingers and periorificial area. 2. Vulgaris vitiligo- This is characterized by scattered patches that are widely distributed. 3. Universal vitiligo- Complete or nearly complete depigmentation of the body occurs. Is associated with endocrinopathies. 4. Lip-tip vitiligo: Involves the lips ,Tip of penis, Vulva, Nipple

11. Acrofacial vitiligo

12. Vulgaris vitiligo

13. Universal vitiligo

14. Lip-tip vitiligo

15. DIFFERATIALS OF VITILIGO and DIFFERENTIATING SIGNS & S/O 1. Piebalism Present at birth, nonprogressive, coalescing depigmented patches, usually near the midline on the front, including a forelock of white hair.

16. 2. Tuberous sclerosis Typical ash-leaf hypopigmented macules, seizures, angiofibroma , and mental retardation. Occurs predominately on the thorax and legs.

17. 3. Lichen Sclerosus Women: typically presents in females as pruritic white plaques in the genital area associated with epidermal atrophy and scarring. Vulva involvement may present with dysuria and dyspareunia . Men: Occurs almost exclusively in those who are uncircumsized .

18. 3. Nevus depigmentosus Congenital condition usually noted at birth or in early childhood. Hypopigmented solitary patch with jugged edges, typically on the trunk. Usually remains at the same site, but may grown in proportion to body growth

19. 4. Pityriasis alba Asymptomatic ill-defined small patches with fine scaling typically on the cheeks of children and adolescents, often with with atopic dermatitis

20. 5. Pityriasis versicolor Polycyclic, well dermarcated lesions lesions with fine scaling, on the upper trunk.

21. 6. Incontinentia pigmenti Distributed along Blaschko lines, history of vesicular eruption perinatally , female gender.

22. Diagnosis Skin biopsy ANA( Antinuclear Antibody). Helps to determine if the patient has other autoimmune disease. CBC with differential Thyroid functioning taste.

23. HISTOLOGY Absences of melanocytes 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.

24. TREATMENT 1. CHEMETHERAPY Topical corticosteroids: mometazone, hydrocortisone etc TCIs: tacrolimus ointment,Pimecrolimus cream Vitamin D analogues: Calcipotriol, Tacalcitol. Alpha-MSH analogues : Afamelanotide 2. PHOTOTHERAPY Narrow band ultraviolet UV-B. Photochemotherapy-Involves the use of psoralens combined with UVA radiation.Psoralen is applied topically or taken orally followed by exposure to artificial / natural UVA radiation. 3. LASER THERAPY laser produces monochromatic rays at 308 nm to treat limited, stable patches of vitiligo. 4. SURGICAL Thin dermoepidermal grafting. Suction epidermal grafting.