Vitiligo

Leuckotrichia has good prognosis [Ref. Neeta Khanna [‘Ye p 118-120] VITILIGO

Etiology:

The exact etiology is not known and may vary from one pattern of disease to another

Genetic

–  A genetic factor is definitely important. since about 20-30% of patients give a positive family history.

– Inheritance may be polygenic.

Autoimmune hypothesis

Evidence points to autoimmune etiology because

– Vitiligo is frequently associated with autoimmne disorders like alopecia areata and thyroid disorder. – Antibodies to melanocytes have also been demonstrated.

– Histopathology of early lesions demonstrate presence of lymphocytes in the lesions.

Neurogenic hypothesis

– Dermatomal distribution of some types of vitiligo (e.g. segmental vitiligo) suggests that a toxin, which destroys melanocyte is released at the nerve endings.

Epidemiology:

• Affects both sexes equally
• Affects all ages, peak incidence between 10-30 years.

Clinical features:

Morphology

• Depigmented macules are the hallmark of vitiligo.
• Typical macule of vitiligo has a chalky or milky white colour, but the pigment loss may be partial in some lesions.
• Sometimes three shades arichrome) occur in the same lesion i.e. the depigmented centre is surrounded by hypopigmented rim which in turn has normally pigmented skin around it.
• The macules have a scalloped outline and on fusion with neighbouring lesions form geographical patterns.
• The hairs in the lesion may remain normally pigmented though in older lesions the hair pigment may be lost (leucotrichia).
• Koebner’s phenomenon can occur in active phase.

Sites

• The lesion can occur in any part of the body.
• Areas subjected to repeated trauma and friction are frequently affected e.g. the backs of hands and feet, elbows and knees.

Diagnosis:

The diagnosis of vitiligo is based upon.

• Age of onset (usually not present at birth).
• Depigmented macules (milky white) with scalloped borders.
• Leucotrichia
• Koebner’s phenomenon
• Predilection for sites of trauma.

NBUVB – Narrow Band Ultraviolet -B Phototherapy

Course of disease:

D i.e. Diabetes mellitus

C. i.e. Melanocytes are absent

A. ie. PUVA

D i.e. All, A i.e. P. Versicolor; B i.e Vitiligo; C i.e. Porphyria 

B. i.e. Vitiligo

C i.e. Vogt-Koyanagi Syndrome 

It is an idiopathic multisystem autoimmune disorder against melanocytes causing inflammation of melanocyte containing tissueQ (eg uvea, skin, meninges & ear) disorder which typically affects Hispanics, Japanese & pigmented individuals & associated with HLA-DR4 & Dw 15

Ans. B: Absent melanocytes

Vitiligo is a chronic disorder that causes depigmentation of patches of skin.

It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes.

Melanocytes are absent.

Vitiligo is a focal failure of pigmentation d/t genetically predisposed destruction of melanocytesQ by immunological mechanism. So a patch of vitiligo shows marked absence of melanocytes & melanin in epidermis Q. Vitiligo is more common in (or a/w) diabetes mellitusQ,alopecia areata, Addison’s disease and thyroid diseases.

Long standing vitiligo with leucotrichia (depigmented hair), acrofacial lesions (acral Le, periungal, palm, sole & facial around eyes & lips) and lesion on resistant area are indicators of poor prognosis for therapy0.Treatment includes topical steroidse (for localized, <20% skin surface involved), tacrolimus (topical immunomodulators, considered safer for children) and PUVA (= psoralen + UV – A)e etc.

Ans is D

Vitiligo is a long term skin condition characterized by patches of the skin losing their pigment.^[The patches of skin affected become white and usually have sharp margins. The hair from the skin may also become white.Inside the mouth and nose may also be involved.Typically both sides of the body are affected. Often the patches begin on areas of skin that are exposed to the sun. It is more noticeable in people with dark skin.Vitiligo may result in psychological stress and those affected may be stigmatized.

The cause is typically unknown.^[It is believed to be due to genetic susceptibility that is triggered by an environmental factor such that an autoimmune disease occurs. This results in the destruction of skin pigment cells

Ans:D.)Vitiligo.

The patient is suffering from Non-segmental Vitiligo of hands.

Vitiligo

• It is an acquired pigmentary disorder of the skin and mucous membranes that is characterized by circumscribed, depigmented macules and patches.
• The condition is frequently associated with disorders of autoimmune origin, with thyroid abnormalities being the most common.
• Vitiligo lesions are characterized as follows:
  • White or hypopigmented
  • Usually well demarcated
  • Round, oval, or linear in shape
  • Borders may be convex 
  • Range from millimeters to centimeters in size
  • Enlarge centrifugally over time at an unpredictable rate
• Initial lesions occur most frequently on the hands, forearms, feet, and face, favoring a perioral and periocular distribution.
• Clinical variants
  • Trichrome vitiligo: An intermediate zone of hypochromia is located between the achromic center and the peripheral unaffected skin, resulting in 3 shades of color—brown, tan, and white—in the same patient
  • Marginal inflammatory vitiligo: Lesions have a red, raised border, which is present from the onset of vitiligo (in rare cases) or may appear several months or years after the initial onset; mild pruritus may be present
  • Quadrichrome vitiligo: Reflects the presence of a fourth color (ie, dark brown) at sites of perifollicular repigmentation 
  • Blue vitiligo: Results in blue coloration of vitiligo macules
  • Koebner phenomenon: Development of vitiligo in sites of specific trauma, such as a cut, burn, or abrasion.
• Vitiligo can be classified as follows:
  • Localized
    • Focal: Characterized by 1 or more macules in 1 area, most commonly in the distribution of the trigeminal nerve
    • Segmental: Manifests as 1 or more macules in a dermatomal or quasidermatomal pattern; occurs most commonly in children; more than half the patients with segmental vitiligo have patches of white hair or poliosis
    • Mucosal: Mucous membranes alone are affected
  • Generalized
    • Acrofacial: Depigmentation occurs on the distal fingers and periorificial areas
    • Vulgaris: Characterized by scattered patches that are widely distributed
    • Mixed: 
  • Universal:
    • Universal vitiligo results in complete or nearly complete depigmentation. It is often associated with multiple endocrinopathy syndrome.
• Microscopic examination of involved skin :
  • It shows a complete absence of melanocytes in association with a total loss of epidermal pigmentation. Superficial perivascular and perifollicular lymphocytic infiltrates may be observed at the margin of vitiliginous lesions, consistent with a cell-mediated process destroying melanocytes.
• Management
  • Nonsurgical treatments
    • Systemic phototherapy: Induces cosmetically satisfactory repigmentation.
    • Laser therapy
    • Steroid therapy
    • Depigmentation therapy: If vitiligo is widespread and attempts at repigmentation have not produced satisfactory results, depigmentation may be attempted in selected patients
    • Micropigmentation: Tattooing can be used to repigment depigmented skin in dark-skinned individuals
• Surgery
  • The basic types of repigmentation surgery are as follow :
    • Noncultured epidermal suspensions
    • Thin dermoepidermal grafts
    • Cultured epidermis with melanocytes or cultured melanocyte suspensions.

Ans. is ‘d’ i.e., Crohns disease

Vitiligo is associated with the following autoimmune diseases :-

• Alopecia areata
• Diabetes mellitus
• Hyperthyroidism
• Hypothyroidism
• Pernicious anemia
• Addison disease
• Multiple endocrinopathy syndrome

Ans:D.)All ofthe above.

Koebner Phenomenon is shown in the image.

KOEBNER PHENOMENON

• The Koebner phenomenon or the isomorphic response, refers to skin lesions appearing on lines of trauma.
• The Koebner phenomenon may result from either a linear exposure or irritation.
• Conditions demonstrating linear lesions after a linear exposure to a causative agent include: molluscum contagiosum, warts and toxicodendron dermatitis (a dermatitis caused by a genus of plants including poison ivy).
• Causes of the Koebner phenomenon that are secondary to scratching rather than an infective or chemical cause include vitiligo, psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis (Darier disease)