CASE #2: Vitiligo

Vitiligo is an acquired disorder consisting of depigmented macules or patches that usually begins in childhood or young adulthood.8,9 Up to 30% of vitiligo patients report an affected relative,9 but the condition has a multifactorial genetic basis.8 Vitiligo is a result of the loss of epidermal melanocytes. The cause of vitiligo is debated and may involve multiple factors.10 Historically, an autoimmune mechanism for the disorder has been favored9 but, more recently, other factors such as intrinsic melanocytic defects, oxidative stress, and sympathetic neurogenic disturbances have been proposed.8,10 The exact cause is likely multifactorial and variable from one patient to the next.

There are multiple clinical manifestations of vitiligo, and numerous classifications exist. Typically, patients with vitiligo present with depigmented white patches surrounded by a normal or hyperpigmented border.9 The color is uniformly milk- or chalk-white8 with discrete and usually convex borders. The lesions may enlarge centrifugally over time,8 and the hairs within the depigmented areas can also become white.9


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Vitiliginous lesions frequently develop following skin trauma from physical insult, rubbing, or even sunburn. This is called Koebner’s phenomenon or an isomorphic response and is described in other skin conditions (e.g., psoriasis). In vitiligo, this response may explain why lesions are most commonly seen over areas of repetitive minor trauma—hands, feet, elbows, knees, and scalp, as well as perioral, periocular, and genital areas.10

Vitiligo has been associated with numerous other disorders, particularly autoimmune endocrinopathies. The strongest association is with thyroid dysfunction. This dysfunction can be either hyperthyroidism (Graves’ disease) or hypothyroidism (Hashimoto’s thyroiditis).8 Vitiligo also has an association with halo nevi and alopecia areata.10 Other conditions, such as insulin-dependent diabetes mellitus, pernicious anemia, and Addison’s disease, have been associated less strongly with vitiligo.9 Recommendations for screening for associated conditions are inconsistent. Many clinicians only screen patients who are experiencing signs and symptoms of associated conditions,9 while others will screen all patients for thyroid dysfunction or associated autoantibodies.10

Vitiligo can have variable presentations leading to a broad differential diagnosis depending on appearance. Diseases that can mimic vitiligo include morphea, lichen sclerosus, ND, pityriasis alba, tinea versicolor, chemical leukoderma, leukoderma associated with melanoma or scleroderma, postinflammatory hypo- or depigmentation, piebaldism, mycosis fungoides, and multiple other conditions.8,9,10

As mentioned previously, a Wood’s lamp may aid in the diagnosis of vitiligo and help differentiate it from other conditions. It is rarely necessary to perform a skin biopsy to confirm the diagnosis of vitiligo.10 The histopathology of vitiligo reveals complete absence of melanocytes, usually with no associated inflammatory infiltrate.9

The treatment of vitiligo can be very frustrating for both the patient and the practitioner. The highly visible location of the lesions can cause significant patient distress, and the use of support groups and psychological counseling may be helpful. Response to therapy is variable, and the disease can return even after therapy induces repigmentation. Some locations, such as acral sites, can be recalcitrant to therapy. Both cosmetic cover-ups and self-tanners containing dihydroxyacetone can be helpful in improving the appearance of lesions.9

Narrowband UVB radiation two to three times per week is moderately effective in treating vitiligo. Mid- to high-potency topical steroids have also been used to treat this condition, but the repigmentation that occurs has been less stable than that achieved with phototherapy. Topical calcineurin inhibitors have been effective in such areas as the face, neck, and intertriginous areas at increased risk for skin atrophy. Finally, surgical methods have been employed with variable success when medical therapies fail.8,9,10 It was not feasible for the patient presented in this case to return to the clinic twice weekly for phototherapy, so topical therapy with mid-potency corticosteroids alternating with a topical calcineurin inhibitor to minimize steroid-associated side effects was initiated. n

Dr. Doherty is a resident in the Department of Dermatology at Baylor College of Medicine in Houston. He has no relationships to disclose relating to the content of this article.

References

1. Kim SK, Kang HY, Lee ES, Kim YC. Clinical and histopathologic characteristics of nevus depigmentosus. J Am Acad Dermatol. 2006;55:423-428.

2. Chan YC, Tay YK. Hypopigmentation disorders. In: Eichenfield LF, Frieden IJ, Esterly NB, eds. Neonatal dermatology. 2nd ed. Philadelphia, Pa.: Saunders-Elsevier;2008:375-395.

3. Coupe RL. Unilateral systematized achromic nevus. Dermatologica. 1967;134:19-35.

4. Xu AE, Huang B, Li YW, et al. Clinical, histopathological and ultrastructural characteristics of naevus depigmentosus. Clin Exp Dermatol. 2008;33:400-405.

5. Bardazzi F, Balestri R, Antonucci A, Spadola G. Lentigines within nevus depigmentosus: a rare collateral effect of UVB therapy? Pediatr Dermatol. 2008;25:272-274.

6. Shim JH, Seo SJ, Song KY, Hong CK. Development of multiple pigmented nevi within segmental nevus depigmentosus. J Korean Med Sci. 2002;17:133-136.

7. Moss C. Mosaicism and linear lesions. In: Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. 2nd ed. Philadelphia, Pa.: Mosby-Elsevier; 2008:841-855.

8. Ortonne JP. Vitiligo and other disorders of hypopigmentation. In: Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. 2nd ed. Philadelphia, Pa.: Mosby-Elsevier; 2008:913-938.

9. James WD, Berger TG, Elston DM. Disturbances of pigmentation. In: Andrews’ Diseases of the Skin: Clinical Dermatology. 10th ed. Philadelphia, Pa.: Saunders-Elsevier; 2006:853-868.

10. Taïeb A, Picardo M. Clinical practice. Vitiligo. N Engl J Med. 2009;360:160-169.