Vitiligo

Basics

Description

  • An acquired depigmentation of the skin, which correlates with a loss of epidermal melanocytes. There are three clinical variants, each with subtypes.
  • Localized: often in childhood, rapid onset then stabilizes. Involvement of hair is common early in the course; lacks associated autoimmune diseases
    • Focal: few lesions, random distribution
    • Segmental: Lesions occur within a dermatome (mostly trigeminal) or may follow Blaschko lines. Lesions usually stop abruptly at the midline.
    • Mucosal: only mucosal surfaces involved
  • Generalized/nonsegmental (most common variant): progressive, with flares, commonly associated with autoimmunity. Common locations are acral, periorificial, and in sites sensitive to pressure/friction (Koebner phenomenon).
    • Vulgaris: most common subtype; scattered macules; often symmetric, wide distribution; mostly hands, axillae, and groin
    • Acrofacial: on distal extremities and face
    • Mixed: coexistence of above
  • Universal: involves >80% of the body surface area (BSA). Most likely to have family history; comorbidities are common and associated with poorest quality-of-life (QOL) scores.
  • Other rare variants
    • Ponctué: discrete, confetti-like macules
    • Inflammatory: peripheral erythematous rim
    • Trichrome: Tan zone is present between normal and depigmented skin.
    • Quadrichrome: as above but with marginal/perifollicular hyperpigmentation
    • Blue: Dermal melanophages give blue hue in areas affected by prior postinflammatory hyperpigmentation.
  • System(s) affected: skin, mucous membranes
  • Synonym(s): leukoderma

Epidemiology

  • 50% begin before age 20 years, peak in females: 1st decade; males: 5th decade. Onset earlier with positive family history; can appear as early as 6 weeks
  • Predominance: male = female; however, females are more likely to seek treatment.
  • No race or socioeconomic predilection

Prevalence
~1% in the United States and Europe (1); 0.1–8% in the world; highest in Gujarat, India at 8.8% (1),(2)

Etiology and Pathophysiology

Most likely a spectrum of disorders with a common phenotype and multiple mechanisms contribute to the pathology (convergence theory).

  • Genetic: See “Genetics.”
  • Autoimmune: humoral autoantibodies and skin-homing T cells
  • Neural: local or systemic dysregulation leading to excess neurotransmitters
  • Viral: direct melanocyte toxicity, cytomegalovirus (CMV), hepatitis C, and Epstein-Barr virus (EBV) found in lesional biopsies
  • Oxidative stress from elevated H2O2 and NO and decreased catalase and erythrocyte glutathione

Genetics

  • Polygenic/multifactorial inheritance
  • 20% of patients report affected relative, but monozygotic twins have only 23% concordance.
  • HLA haplotypes, small nucleotide polymorphisms, and specific genes are all possible contributors.

Risk Factors

  • Family history of vitiligo/autoimmune disorders
  • Personal history of associated conditions

Commonly Associated Conditions

  • Most common
    • Endocrine: thyroid disease (hypo-/hyperthyroidism), hypoparathyroidism, Addison disease, insulin-dependent diabetes
    • Dermatologic: psoriasis, atopic dermatitis, alopecia areata, chronic urticaria, halo nevi, ichthyosis
    • Pernicious anemia
    • Hypoacusis, rheumatoid arthritis
    • Ocular abnormalities in up to 40%
    • Elevated antinuclear antibodies in up to 40%
    • Elevated thyroperoxidase antibodies in 50%
  • Less common
    • Systemic lupus erythematosus
    • Inflammatory bowel disease
    • Melanoma (may be a sign of positive outcome of melanoma) and other skin cancers
    • Syndromes: Alezzandrini; mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS); Schmidt; and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED)
  • Age >50 years at onset should prompt investigation for associated conditions.

Pediatric Considerations
Associated with Hashimoto thyroiditis in a significant portion of children. Screening at onset and possibly annually may be beneficial.

There's more to see -- the rest of this topic is available only to subscribers.