Diffuse hyperpigmentation in systemic sclerosis tied to digital ulcers
There appears to be a link between diffuse hyperpigmentation and the occurrence of digital ulcers in patients with systemic sclerosis (SSc), a recent study has shown.
In 239 SSc patients enrolled (mean age 59.7±12.8 years; 74.5 percent female), five patterns of skin pigmentation were identified: diffuse hyperpigmentation; hyperpigmentation of areas exposed to the sun; hypopigmentation of the face, neck and/or chest; acral hypopigmentation; and diffuse hypopigmentation.
Majority (70.7 percent; n=169) of the participants had limited cutaneous SSc, while the remaining 29.3 percent (n=70) were classified as having diffuse cutaneous SSc. Eighty-eight patients (36.8 percent) had skin pigmentation disorders, of which 58 and 35 were cases of hyperpigmentation and hypopigmentation, respectively. The mean Modified Rodnan skin score (MRSS) was 9.4.
Diffuse SSc occurred with significantly greater frequency in patients with hyperpigmentation (p=0.003), particularly in those with diffuse hyperpigmentation (p=0.001). Diffuse hyperpigmentation was also significantly correlated with a higher MRSS (p=0.001).
In terms of clinical features, the mean duration of Raynaud phenomenon was significantly shorter in patients with vs without hyperpigmentation (10.3±8.6 vs 17.9±13.3 years; p=0.0001).
Moreover, vascular involvement, particularly the presence of digital ulcers (p<0.01 for both), was significantly more common in those with diffuse hyperpigmentation. The same was true for interstitial lung disease (p<0.05) and pericarditis (p<0.01).
Multivariate logistic regression analysis further confirmed the significant link between vascular involvement and diffuse hyperpigmentation (odds ratio, 2.96; 95 percent CI, 1.28–6.89).