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Vitiligo

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Absence of epidermal melanin due to autoimmune destruction of melanocytes.
Mecanismo
  • Absence of functional melanocytes secondary to melanocyte destruction
  • Pathogenic causes
    • Genetic background: poligenic (6% risk if first degree relative, 23% if twin affected)
    • Dysfunctional biochemical pathways: IFN-gama-CXCL10 chemokine axis
    • Autoimmune processes: innate and adaptative immune system
      • Cytotoxic activity of autoreactive T-Cells agains melanocytes
      • IL-15 appears essential for bringing the reactive T cells into the skin and keeping them there
      • JAK 1 and 3 also involved
      • Treated with immunosuppression
    • Melanocyte adhesion deficits
    • Nervous system imbalances: segmental vitiligo
Epidemiology
  • Prevalence 0,5-2% population
  • No gender or race predilection
Apresentação clínico
  • Koebner phenomenon - important in skin of color
  • Scratiching → Koebner → vitiligo
  • Sinais de atividade
    • Hipopigmentation border
    • Conffeti like pattern around
    • Koebner phenomenon
    • Trichrome lesions
  • Classification
    • Generalized vitiligo - all ages
    • Segmental - more in children
      • Follows patterns described
      • Less associated with auto-immune disorders except at the site of the segmental vitiligo
Associated diseases
  • Associated with other autoimmune diseases
    • Thyroid (Graves and Hashimoto)
      • If vitiligo on hands → 20% chance of thyroid disease
      • If no vitiligo on hands and feet → 6,4% chance of thyroid disease
    • DM1
    • Alopecia areata
    • PTI
    • Doença Celíaca
    • Systemic lupus erythematosus
    • Rheumatoid arthritis
    • Systemic sclerosis (but distinguish vitiligo is not the salt and pepper pattern sometimes seen in SS)
  • Outras doenças inflamatórias
    • Psoriasis
    • Inflammatory bowel disease
    • Atopic and allergic dermatitis
    • Lichen Planus
  • Halo nevi
  • Premature graying of hair
  • Associação com melanoma porque pode ser uma reação inflamatória contra o melanoma que faz reação cruzada com os melanocitos da pele - procurar
  • Pedir tiróide e autoimunidade (glicose, eventualmente ANA, doença celíaca, plaquetas)
  • Mental health conditions
    • OCD
    • Body dysmorphic disorder
    • Anxiety
    • Depression
    • Sleep disturbance
DDx
notion image
  • Vog Koyonara Harada (involves eyes)
  • Lichen striatus
  • Blashkitis
Prognóstico
  • Bad prognostic indicators: mucosal involvement, family history, non-segmental disease
  • Good prognostic indicators: younger patients, lesions of face, neck, trunk
  • Although there is less melanin on the skin there is a reduction in the risk of melanoma and non-melanoma skin cancer
    • Lower mutational burden in vitiligo lesions, despite lack of pigmentation
    • Increased DNA repair may decrease mutational burden and skin cancer risk
 

Tratamento

Considerações gerais
  • Repigmentation occurs from the hair follicle (melanocyte stem cells are interfollicular and at the base of hair follicles - and the ones at the hair follicles are spared) - proteção imunológica?
  • Quando é segmentar não responde tão bem ao tratamento
  • Goals of treatment: Halting the progression of the disease
Guidelines
Tratamentos
  • Tratamentos disponíveis
    • Protopic (tacrolimus tópico) e Pimecrolimus (elidel)
    • Corticoide tópico
      • Ex. Corticoides (mometasona) 3x/semana + protopic ou elidel nos outros dias
    • Fototerapia (narrow band UVB)
      • PUVA historically was the first to be used
        • Now nbUVB is 1st option
        • Friedman’s protocol shows the initial dose according to the site of the lesion
            • notion image
        • Increase 10% every week
      • 2001 Baltas introduced excimer light in vitiligo
      • 2013 European Guidelines: Excimer light as the most efficacy phototherapy in vitiligo
      • Fenilalanina 100mg/kg 1h antes da fototerapia
    • Dermoestéticos
      • Protetor solares
      • Repigment 12 Bella Aurora creme repigmentante 71€ 75ml
      • RepigmentSun Bella Aurora cápsulas solares 24€ 30 caps (1 mês)
  • Treatment of an active form of vitiligo
    • Oral minipulse therapy with corticosteroids
      • 2 consecutive days a week for >3 months
    • Methotrexate, cyclosporine, minocycline gave shown some efficacy, but not enough evidence (not indicated for treatment)
    • Nb-UVB seems more relevant to halt the progression of the disease and has the advantage of also promoting a repigmentation of vitiligo lesions
    • Combination of Nb-UVB and OMP in the very active formes of the disease
  • Exemplo de esquema
    • FACE
      • 2-3 meses: protopic durante a semana, dermovate ao fim de semana
      • Depois: protopic diário
    • CORPO
      • 2-3 meses: dermovate durante a semana, protopic ao fim de semana
      • Depois: protopic durante a semana, dermovate ao fim de semana
    • Se extenso fototerapia
    • Se progredir: pulsos de corticoide ao fim de semana 6 meses
    • Parar o tratamento se houver repigmentação ou não melhorar ao fim de 6-12 meses
  • Novos tratamento
    • Topical Ruxolitinib (JAK inhibitor)
        • notion image