Vitiligo

From Anvita Health Wiki

Contents 1 Etiology 2 Epidemiology 3 Pathology 4 Genetics 5 Clinical-manifestations 6 Laboratory 7 Diagnostic-procedures 8 Differential-diagnosis 9 Management 10 More General Terms 11 Additional Terms 12 Internet Database 13 References

Etiology

• presumed autoimmune in origin, anti- melanocyte
• often seen in association with autoimmune disorders

• thyroid disease

• Hashimoto's thyroiditis
• Graves disease

• diabetes mellitus
• Addison's disease
• pernicious anemia
• alopecia areata
• rheumatoid arthritis

• 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

• 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

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
• generalized vitiligo tends to occur in a symmetric pattern
• 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

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

Diagnostic-procedures

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

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

• 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)

Internet Database

OMIM: 193200

References

1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 952-53
2. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 296
3. Medical Knowledge Self Assessment Program (MKSAP) 15, American College of Physicians, Philadelphia 2009
4. NIH Institute and Center Resources [1]
5. National Guideline Clearinghouse Guideline for the diagnosis and management of vitiligo. British Association of Dermatologists ngc-guideline: [2]

vitiligo