Vitiligo and Other Disorders of Hypopigmentation

54


Vitiligo and Other Disorders of Hypopigmentation






Vitiligo



An acquired disease, due to autoimmune destruction of melanocytes, that is characterized by circumscribed, amelanotic macules or patches of the skin and mucous membranes (Fig. 54.2); hairs within involved areas may be depigmented or pigmented; the uveal tract and retinal pigmented epithelium can also be affected.



Two major subtypes of vitiligo: generalized (most common) and localized (Fig. 54.3).



A polygenic disorder, i.e. involving multiple susceptibility genes, plus environmental factors (mostly unknown); increased incidence of other autoimmune disorders, either in the individual with vitiligo (generalized > localized) or in family members.


10–15% of patients with generalized vitiligo have systemic autoimmune diseases, in particular thyroid disease (Hashimoto’s thyroiditis or Grave’s disease), pernicious anemia, Addison’s disease, and AI-CTD (e.g. SLE); associated cutaneous disorders include halo melanocytic nevi, alopecia areata, and lichen sclerosus.


Generalized vitiligo.


Includes acrofacial, vulgaris, and universal (see Fig. 54.3); occasionally an inflammatory edge is seen (Fig. 54.4).



Affects ~1% of the population worldwide; males = females; onset in ~50% before age 20 years; onset after age 50 years is unusual and prompts widening of the DDx (see below).


The typical lesion is an asymptomatic, amelanotic macule or patch that is milk or chalk-white in color; early on the pigment loss may not be complete; margins are fairly discrete and convex.


Course is unpredictable, but often progressive.


Segmental vitiligo.


Usually begins in childhood; typically presents in a unilateral, segmental pattern that respects the midline and usually remains stable in size after 1–2 years (Fig. 54.5).



DDx: nevus depigmentosus (decreased but not total loss of pigment).


DDx of depigmented lesion(s).


In a child: if 1–2 isolated circular or oval macules, stage 3 halo nevus; piebaldism, Waardenburg syndrome (see below).


In an adult: chemical leukoderma, melanoma-associated leukoderma, leukoderma of scleroderma, Vogt–Koyanagi–Harada syndrome, onchocerciasis, and postinflammatory depigmentation (see below).


With the exception of onchocerciasis, or in areas of sclerosis or inflammation, a biopsy is not particularly helpful.


Vitiligo and ocular disease.


Uveitis is the most significant ocular abnormality; asymptomatic depigmented areas of the ocular fundus can also be seen.


Uveitis is a major component of the Vogt–Koyanagi–Harada syndrome, in which patients also develop aseptic meningitis, otic involvement (e.g. dysacousia), poliosis, and vitiligo, especially of the head and neck region.


Alezzandrini syndrome is a rare disorder characterized by unilateral facial vitiligo, poliosis, and ipsilateral ocular involvement.


Rx: primarily directed at repigmentation of patient-desired areas (Fig. 54.7).


The efficacy of treatment depends on four variables.


1. Site: face, neck, mid extremities > acral, mucosal (i.e. sites without hairs).


2. Extent of involvement: small area > large area.


3. Stability: stable > active or progressive.


4. Pigmented hairs within the vitiligo patch: presence > absence.


Repigmentation usually appears in a perifollicular pattern (Fig. 54.6) and/or from the periphery of lesions.


10–20% monobenzyl ether of hydroquinone (MBEH) is sometimes used as depigmentation therapy for widespread or treatment-resistant vitiligo, but it can be permanent and lead to loss of pigment in areas distant to the sites of application.




image


Fig. 54.7 Treatment options for vitiligo. Treatment of vitiligo is directed at repigmentation of patient-desired areas. Camouflage can be offered to all patients for temporary (e.g. makeup, self-tanners) or more permanent (e.g. tattoos) cosmetic relief. Referral to a support group [e.g. National Vitiligo Foundation (www.mynvfi.org)] may also be helpful. 10–20% monobenzyl ether of hydroquinone (MBEH) is sometimes used as depigmentation therapy for widespread or treatment-resistant vitiligo, but it can be permanent and lead to loss of pigment in areas distant to the sites of application. NB-UVB, narrowband ultraviolet B; BB-UVB, broadband UVB; PUVA, psoralens plus ultraviolet A.



Hereditary Hypomelanosis



Apr 22, 2016 | Posted by in Dermatology | Comments Off on Vitiligo and Other Disorders of Hypopigmentation

Full access? Get Clinical Tree

Get Clinical Tree app for offline access