Study Identifies Bidirectional Association Between Systemic Sclerosis and Vitiligo

A recent study identified a bidirectional association between systemic sclerosis (SSc) and vitiligo.

Vitiligo’s underlying pathogenesis has multiple factors, including T cell-mediated autoimmune responses, genetic predisposition, and inherent melanocyte defects, and patients with the skin condition have reported elevated risk of other autoimmune comorbidities.

Despite the fact that SSc’s coexistence with vitiligo has been reported anecdotally, there has not been an in-depth study of the epidemiological association between both conditions. This is why the study was led by Khalaf Kridin MD, PhD, of the Baruch Padeh Medical Center’s Unit of Dermatology and Skin Research Laboratory.

“A robust bidirectional association exists between vitiligo and SSc,” Kridin and colleagues wrote. “This knowledge is valuable for physicians managing patients with both conditions. Patients with vitiligo and comorbid SSc might be monitored for cardiovascular and metabolic comorbidities.”

Background

The investigators used a population-based study, designed to compare the vitiligo patient arm of the study (n = 20,851) with control subjects who were sex-, age-, and ethnicity-matched (n = 102,475). The study participants would be compared with regard to both the incidence of new-onset and the prevalence of preexisting SSc.

The team recruited a total of 123,326 participants for the study, 20,851 were reported as vitiligo patients. The mean (SD) age at the time of vitiligo diagnosis was reported as 34.7 (22.4) years, and 50.7% (10,570) of the patients were listed as female.

Findings

The investigators found in their study that vitiligo patients were 5.4-times more likely to end up with SSc, with the risk being higher among both females and younger patients. Preexisting SSc patients were then found to have more than twofold increased chance of ending up with subsequent vitiligo. The researchers found that “those with vitiligo and comorbid SSc were older, more likely to be female, and had a higher burden of ischaemic heart dis- ease, hyperlipidaemia, and hypertension.”

The research team noted that the mechanism underlying the coexistence of SSc and vitiligo has not been delineated, though they point out several potential hypotheses to account for this. Overall, the study works as a step into a greater world of understanding for the relationship between the conditions.

“In conclusion, a significant bidirectional association was confirmed between vitiligo and SSc in the current population-based study,” they wrote. “To elaborate, patients with vitiligo were at a fivefold increased risk of developing SSc, whereas a preexisting diagnosis of SSc predisposes individuals to have subsequent vitiligo. Female sex, older age, and increased prevalence of cardiovascular and metabolic comorbidities were all linked to patients with vitiligo and comorbid SSc.”

This study, “Vitiligo and systemic sclerosis: Are they associated?– Lessons from a population-based study,” was published in the Australasian Journal of Dermatology.