Exploring the Common Characteristics in Psoriasis and Vitiligo

Allison Inserro

Both conditions involve a genetic predisposition as well as immune pathways that are triggered by environmental factors.

Some patients have both vitiligo and psoriasis, and a recent study examined the demographics and characteristics of this population.

Vitiligo is a condition in which skin cells are destroyed, causing the loss of pigment and creating a patchy appearance. It is chronic and there is no cure. The authors said that both conditions involve a genetic predisposition as well as immune pathways that are triggered by environmental factors.

The study was conducted in France at a single center between January 2017 and January 2020. Of the 436 patients with vitiligo, 74 had a past and/or current personal history of psoriasis. Of the patients with both diseases, 45 were women.

Vitiligo was assessed using the Vitiligo European Task Force questionnaire and the Vitiligo Extent Score (VES). Thyroid-stimulating hormone (TSH) and thyroid autoantibodies were measured. Psoriasis was assessed using the Psoriasis Area and Severity Index (PASI).

Results showed:

  • Plaque-type psoriasis was the most common when there was a co-occurrence of psoriasis and vitiligo (48 patients).
  • The occurrence of psoriasis was reported before development of vitiligo by 46 patients, especially among those with colocalization of psoriasis and vitiligo (10 of 12 patients).
  • In 12 patients, psoriasis lesions were located at the same site as vitiligo.
  • The mean age of onset was younger for patients with psoriasis than for vitiligo (28 years vs 34.6 years, respectively).

Multivariate logistic regression analyses showed that patients with both psoriasis and vitiligo had a higher risk for autoimmune disease (odds ratio [OR], 11.8; 95% CI, 3.4-41; P < .001) and had a family history of psoriasis (OR, 2.4; 95% CI, 1.02-5.77; P = .046).

In patients with a history of psoriasis, researchers did not see an independent association with atopic disease, and they said this suggests that patients with both diseases are affected by an altered immune response to T-helper 17 (Th17) cells and Th1.

In addition, the authors said untangling the 2 diseases is challenged by separating vitiligo from hypopigmentation in areas of skin previously affected by psoriatic lesions.

Remarking on the finding that psoriasis came before vitiligo, the authors said that is “consistent with recent translational research ing the presence in psoriatic skin of memory CD8+ T cells directed against the melanocyte-derived protein ADAMTSL5 that may favor the development of vitiligo in a predisposed patient.”

Although there are no therapies for vitiligo that exist, they suggested that psoriasis treatments could be trialed in these patients.

The study was published this month in the Journal of the European Academy of Dermatology and Venereology.

Reference

Boniface K, Ezzedine K, Seneschal J, et al. Demographic and clinical characteristics of patients with both psoriasis and vitiligo in a cohort of vitiligo patients: a cross sectional study. J Eur Acad Dermatol Venereol. Published online May 20, 2021. doi:10.1111/jdv.17383