Vitiligo

Definition and Epidemiology

Definition

Vitiligo is a progressive skin condition in which there is destruction of melanocytes resulting in the loss of skin pigmentation.

Epidemiology

• Most common cause of depigmentation
• Prevalence: 0.1%–2% of the general population
• Occurs in children and adults
• Equal incidence in males and females
• No racial or ethnic predilection
• Age:
  • Onset generally occurs before 30 years of age.
  • Peak incidence: 10–30 years of age

Etiology and Pathophysiology

Etiology

The cause of vitiligo is unknown, but is postulated to be a result of multiple factors.

• Possible genetic component: up to 50% of affected individuals have a family history of the condition
• May be autoimmune mediated:
  • Approximately 20% of affected individuals have an autoimmune condition.
  • Associated conditions: 
    • Hashimoto’s thyroiditis
    • Graves’ disease
    • Type 1 diabetes mellitus
    • Addison’s disease
    • Pernicious anemia
    • Alopecia areata
    • Psoriasis
    • Inflammatory bowel disease
  • The presence of antibodies to melanin has been noted.
• Oxidative stress
• Intrinsic defects of melanocytes

Pathophysiology

• Destruction, or disappearance, of melanocytes → loss of pigmentation in the affected area of the skin
• This process gives the appearance of white patches on the skin.

Clinical Presentation and Diagnosis

Clinical presentation

Vitiligo results in hypopigmented or depigmented areas.

• Distribution: 
  • Widespread (generalized) with mucosal involvement
  • Segmental (entire body segments)
  • Localized
• Lesions’ appearance:
  • Sharply demarcated
  • Macules or patches
  • Milky or chalk-white color
• Most commonly affected areas: 
  • Face
  • Periorificial areas: 
    • Mouth
    • Anus
  • Genitalia
  • Elbows
  • Hands
  • Knees
• Hair in affected areas may also be depigmented.

Diagnosis

The diagnosis is usually clinical. However, the following examinations may be used if the diagnosis is unclear:

• Exam with a Wood’s lamp:
  • Handheld device that emits ultraviolet (UV) A light
  • Useful in patients with pale skin where vitiligo lesions are more subtle
  • Accentuates hypo- or depigmented areas (appear white)
• Biopsy: 
  • Can be used to differentiate from other hypopigmented disorders
  • Findings:
    • Absence of melanocytes
    • Loss of epidermal pigmentation
    • Perifollicular lymphocytic infiltrate may be seen in some patients.

Management and Prognosis

General management and considerations

No cure is currently available. Management generally aims to slow the progression of the disease and address cosmetic issues.

• Basic measures:
  • All patients should practice sun avoidance and protection.
  • Thyroid function testing should be performed due to the strong association with thyroid disease.
  • Counseling and other psychological intervention should be considered due to the effects of the disease on patients’ mental health and self-esteem.
• Choice of therapy depends on: 
  • Severity
  • Percentage of body surface area affected
  • Whether lesions are stable or progressive
  • Patient preference

Medical therapy

• Topical corticosteroids: 
  • Useful in localized disease
  • Care should be used in sensitive areas due to the risk of skin atrophy.
• Topical calcineurin inhibitors: 
  • Options: tacrolimus, pimecrolimus
  • An alternative to topical steroids
  • Preferred in areas at high risk of skin atrophy (e.g., skin, genitals, intertriginous regions)
• Systemic glucocorticoids: 
  • Oral or intramuscular
  • 1st-line therapy for stabilization of rapidly progressive disease
• Systemic immunosuppressants: 
  • Options: methotrexate, mycophenolate, cyclosporin
  • An alternative to systemic steroids

Other therapies

• Phototherapy:
  • Often used in conjunction with medical therapy
  • Used alone for stabilization of rapidly progressive disease if steroids are contraindicated
• Depigmentation therapy:
  • For extensive disease involving > 40% of body surface area
  • Used on areas of unaffected skin
  • Goal is to match the diseased area for cosmetic satisfaction.
• Surgical transplantation procedures:
  • Techniques: skin grafts, autologous melanocyte cultures
  • May be used for stable, localized lesions

Prognosis

• Vitiligo is a chronic skin condition.
• The clinical course is unpredictable.
• Lesions may stabilize or continue to progress and expand over the years, despite treatment.

Differential Diagnosis

• Nevus depigmentosus: typically a benign, solitary, localized hypopigmented macule or patch that is often noted at birth or in the early years of life. These lesions are stable and not progressive, although they may appear to enlarge as the body grows. Nevus depigmentosus is caused by defective melanocytes that cannot produce pigment or transfer it to keratinocytes. Management is not necessary and, when attempted, has varied results.
• Pityriasis alba: a common skin disorder typically affecting children and adolescents. The condition is often considered a manifestation of atopic dermatitis. Typically, patients present with erythema and scale followed by round, hypopigmented macules and patches, which commonly occur on the face, upper trunk, or upper limbs. The diagnosis is clinical. Pityriasis alba is considered self-limiting, but may take months to years to resolve. Topical steroids, emollients, and calcineurin inhibitors may be used to speed up resolution.
• Tinea (pityriasis) versicolor: a common superficial fungal infection caused by Malassezia furfur. Tinea versicolor may present as hypopigmented, hyperpigmented, or erythematous macules and patches, most often on the trunk. Diagnosis is often clinical but may be confirmed with visualization of hyphae and budding cells on potassium hydroxide wet mount. Management is with topical or oral antifungals.
• Halo nevus: a mole surrounded by a halo of hypopigmentation. Multiple lesions may be present, and the back is most often affected. Loss of pigment often precedes spontaneous resolution of the central nevus. Repigmentation of the skin may occur after the nevus disappears. The diagnosis is generally clinical. No treatment is necessary.
• Chemical leukoderma: also known as occupational vitiligo, hypopigmentation of the skin resulting from contact with certain chemicals that cause melanocytotoxicity. Hypopigmentation initially occurs in the area of contact but may spread to additional areas. The diagnosis is clinical. Management involves removal/avoidance of the offending agent and the use of topical steroids.
• Idiopathic guttate hypomelanosis: benign skin condition that is thought to be a part of the natural aging process and is associated with a decrease in the number of melanocytes. Patients will have diffuse, small, round or oval hypopigmented macules on sun-exposed areas, most often on the extremities. Once present, these lesions are stable and do not change. The diagnosis is clinical. Treatment is not required.