vitiligo

Etiology

• presumed autoimmune in origin, anti-melanocyte
• often seen in association with autoimmune disorders
  • thyroid disease
    • Hashimoto's thyroiditis
    • Graves disease
  • diabetes mellitus type-1
  • Addison's disease
  • pernicious anemia
  • alopecia areata
  • rheumatoid arthritis
  • psoriasis
  • Vogt-Koyanagi-Harada syndrome
    • non-traumatic uveitis
    • aseptic meningitis
• acquired condition, congenital cases are rare

Epidemiology

• incidence is approximately 1%
• affects both sexes equally
• more noticeable in dark-skinned individuals
• peak incidence between 10-30 years

Pathology

• loss & absence of melanocytes
• minimal inflammation

Genetics

• 30% of patients have an affected family member
• inheritance pattern is unclear
• mutations in gene for F-box only protein-11
• susceptibility to vitiligo is associated with variations in PTPN22

Clinical manifestations

• hypopigmented macules
  • 1 mm to several cm in diameter
  • generally white, but may be off-white or tan in color
  • circular or oval in shape, may have scalloped edges
  • accentuated by viewing with Wood's lamp, especially in light-skinned patients
  • focal, segmental or generalized in distribution
  • perifollicular skin may be spared
  • generalized vitiligo tends to occur in a symmetric pattern
  • areas of frequent trauma, i.e. fingertips, bony prominences affected early
  • common sites include
    • extensor surfaces
      • knees
      • elbows
      • back of hands
    • body folds
      • axilla
      • genitalia
    • skin around orifices
      • mouth
      • eyes
      • nostrils
      • nipples
      • umbilicus
    • previously sunburned areas or sites of skin trauma (Koebner phenomenon)
• other skin manifestations
  • leukotrichia
  • halo nevi
  • alopecia areata
• iritis is seen in 10% of patients with vitiligo
• signs associated with concomitant autoimmune disorder

* images

Laboratory

• diagnosis is made by history & physical examination, laboratory testing is rarely needed
• skin biopsy reveals normal skin except for an absence of melanocytes
• screening tests for associated autoimmune disorders
  • free T4 or TSI & serum TSH
  • complete blood count (CBC) for pernicious anemia
  • fasting blood sugar (serum glucose) for diabetes mellitus
  • serum Na+, serum K+ & serum cortisol for Addison's disease
• PTPN22 gene mutation

Diagnostic procedures

• lesions more apparent under Wood's lamp (chalk white)

Complications

• patients with vitiligo more likely to develop dementia (RR=5.3)
  • Alzheimer's dementia (RR=12.2)
  • vascular dementia (RR=4.0)

Differential diagnosis

• tinea versicolor
• tuberous sclerosis
• pityriasis alba
• post inflammatory hypopigmentation
• leprosy
• systemic lupus erythematosus
• chemical leukoderma
• nevus anemicus

Management

• primarily of cosmetic & social concern
• tends to be stable initially, then progresses over several years
• untreated vitiligo usually remains for life, but some individuals spontaneously repigment depigmented areas
• sunscreens (SPF > 30) will diminish pigmentation of adjacent areas which make the vitiligo more noticeable
• cosmetics may provide good results
• pharmacologic agents
  • topical steroids for isolated lesions
    • hydrocortisone 1% or 2.5% on face & skin folds
    • more potent steroids elsewhere
    • use interrupted schedule if steroids are used for more than 6-8 weeks to reduce risk of steroid atrophy
  • topical PUVA photochemotherapy or oral psoralen for more extensive disease
  • topical ruxolitinib (Opzelura) FDA-approved
• depigmentation of normal skin with monobenzone (Benzoquin)
  • permanent, uniform bleaching of remaining normal skin
  • may be useful for patients with extensive disease

More general terms

• pigmentation disorder

Additional terms

• F-box only protein 11; vitiligo-associated protein 1; VIT-1 (FBXO11, FBX11, VIT1, UG063H01)
• Vogt-Koyanagi-Harada syndrome (VKH)

Patient information

vitiligo patient information

Database

• OMIM: https://mirror.omim.org/entry/193200