So, what is vitiligo?
Vitiligo is an acquired pigmentary disorder with a genetic predisposition in which melanocytes progressively lose their function, resulting in abnormal skin hypopigmentation (white macules and patches) throughout the body1,2. The exact pathophysiology of vitiligo remains unknown but multiple hypotheses exist3. While it is not associated with life-threatening outcomes, patients may suffer from significant psychosocial stress and altered quality of life due to their appearance, especially in those with dark skin2.
Vitiligo is divided into either segmental or nonsegmental. Segmental vitiligo presents as asymmetric/unilateral white patches that may partially or fully match a dermatome or a Blaschko line (see Figures 1 and 2)4,3. Nonsegmental, the most common manifestation and seen in up to 90% of patients with vitiligo, is described as white symmetric/bilateral patches that first occur during childhood in areas of previous trauma and increase in size over time3.
Figure 1 Blaschko lines on right vs dermatomes on left3
Table 1 Pigmentation disorders
How am I going to diagnose it?
Luckily, biopsy is not required for the diagnosis, only an astute physical exam is.
Is vitiligo associated with any other concurrent conditions?
While the pathophysiology is uncertain, the most widely accepted cause of vitiligo remains autoimmune in nature, given studies that have shown the presence of auto-antibodies against melanocytes and autoimmune conditions seen in up to 23% of vitiligo patients1. Furthermore, many of the therapeutic options for vitiligo focus on immunosuppression. Of the associated autoimmune disorders, the most common remain hypothyroidism, rheumatoid arthritis, alopecia areata, diabetes mellitus, and systemic lupus erythematosus, which do appear to have a racial variation (see Table 2)1. Therefore, if evaluating a patient with vitiligo, be cognizant of other autoimmune conditions that may be present and the requirement diagnostic evaluation required for each. Screening laboratory assessment for asymptomatic patients is not recommended.
How can I treat vitiligo?
Unfortunately, as with most pigmentary disorders, vitiligo can be challenging to treat, and many options may not provide completely satisfactory results. Options vary depending on the amount of skin involvement, varying from systemic to topical (see Table 3). One of the safest and effective treatments is phototherapy, comprised of narrow-band ultraviolet-B therapy (NB-UVB) and psoralen plus ultraviolet A (PUVA)5. Both UVA and UVB are the first-line treatments for vitiligo affecting more than 10-20% of skin3. They work via both immunosuppression and melanocyte proliferation3. As a provider, you may be more familiar with PUVA, as it has been around longer than other phototherapies. However, its side effect profile including nausea, vomiting, and carcinogenic potential has caused it to fall out of favor among dermatologists. An advantage to phototherapy is that home-treatment options are available, which will lead to increased patient compliance6. The pharmacologic treatments include topical steroids (best for localized vitiligo) and topical calcineurin inhibitors (causes less skin atrophy but a higher cancer risk due to immunosuppression). Synthetic topical vitamin D3 analogs directly inhibit T-cell function and can help with melanocyte maturation and halt further loss7. More extreme treatments involve surgical intervention and are often reserved for those who have had stable lesions for over 2 year and have failed to respond to medical therapy8.
Table 3 Treatments for vitiligo8
References
1. Dahir AM, Thomsen SF. Comorbidities in vitiligo: comprehensive review. Int J Dermatol. 2018 Oct;57(10):1157-64.
2. Zubair R, Lyons AB, Vellaichamy G, Peacock A, Hamzavi I. What’s New in Pigmentary Disorders. Dermatologic Clinics. 2019 Apr;37(2):175-81.
3. Guerra L, Dellambra E, Brescia S, Raskovic D. Vitiligo: Pathogenetic Hypotheses and Targets for Current Therapies. CDM. 2010 Jun1;11(5):451-67.
4. Bolognia JL, Orlow SJ, Glick SA. Lines of Blaschko. Journal of the American Academy of Dermatology. 1994 Aug;31(2):157-90.
5. Scherschun L, Kim JJ, Lim HW. Narrow-band ultraviolet B is a useful and well-tolerated treatment for vitiligo. J Am Acad Dermatol. 2001 JUN:44(6):999-1003.
6. Khanna U, Khandpur S. What is New in Narrow-Band Ultraviolet-B Therapy for Vitiligo? Indian Dermatol Online J. 2019;10(3):234-43.
7. AlGhamdi K, Kumar A, Moussa N. The role of vitamin D in melanogenesis with an emphasis on vitiligo. Indian J Dermatol Venereol Leprol. 2013 Dec:79(6):750-8.
8. Dillon AB, Sideris A, Hadi A, Elbuluk N. Advances in Vitiligo: An Update on Medical and Surgical Treatments. J Clin Aesthet Dermatol. 2017 Jan;10(1):15-28.
9. A double-blind, randomized, placebo-controlled trial of topical tacrolimus 0.1% vs. clobetasol propionate 0.05% in childhood vitiligo. – PubMed – NCBI [Internet]. [cited 2019 Jun 19]. Available from: https://www.ncbi.nlm.nih.gov/pubmed/21457214.
10. Park KK, Liao W, Murase JE. A review of monochromatic excimer light in vitiligo. Br J Dermatol. 2012 Sep;167(3):468-78.