Scleroderma (SSc) is an autoimmune disease characterized by fibrosis (or collagen deposition) of the skin and internal organs. The extent of skin fibrosis is an important predictor of internal organ complications and increased mortality. Currently a very imprecise, subjective method that varies amongst different doctors for the same patient is used to quantify skin fibrosis in patients, by "pinching" their skin and assessing how thick it is; this is the method used to determine the modified Rodnan skin score (mRSS).

A previous plot study was conducted by the investigators to determine if spatial frequency domain imaging (SFDI), a method of light scattering, could be used to measure the collagen content in the skin of SSc patients. This non-painful, noninvasive method takes very little time and the investigators hypothesized that it would be more accurate than the "pinching" method. For that pilot study, patients with various stages of the disease were selected, and SFDI was used to image 6 areas. A forearm skin biopsy was taken for subsequent histopathology analyses of collagen content. The clinical mRSS was assessed at the time of SFDI measurement. Optical property imaging data was analyzed and statistically correlated and analyzed with immunohistochemistry (a method of identifying proteins) of the skin. Preliminary results demonstrated a strong correlation between mRSS and SFDI. Some of the imaging parameters of the SFDI were modified based on the initial results. Initial results demonstrated that the device can detect increases in skin thickness observed in SSc skin.

• The primary objective of this study is to validate spatial-frequency domain imaging (SFDI) and related optical techniques as robust, sensitive, and objective methods for quantifying skin involvement in systemic sclerosis. The study aims to use SFDI/SLIM to examine longitudinal skin changes in early diffuse cutaneous SSc patients and the correlation with change in modified Rodnan Skin Score (mRSS).
• Secondary objectives include assessing correlations between SFDI measurements of skin in SSc subjects and other clinical outcomes such as durometry, ultrasound, histopathological changes in the skin, or scleroderma patient reported outcomes (PROs).

In the current study longitudinal measurements in SSc patients will be taken to examine: the sensitivity and accuracy of SFDI to detect changes in skin thickness over time in response to therapy or from disease progression, the correlation between SFDI measurements and mRSS, and the expression of proteins including PDGFRβ in skin biopsy tissue.

In this study SFDI and other clinical outcome assessments of skin thickness and fibrosis in scleroderma patients including skin biopsy histology, scleroderma skin patient reported outcome (SSPRO), ultrasound, and durometry (durometer measures skin hardness) will be compared. SFDI information will also be compared with capillaroscopy (that allows for non-invasive imaging of the nailfold capillaries) if available from the electronic medical record. If SFDI correlates well with other clinical outcome assessments, it may be used as a rapid, non-invasive tool for monitoring disease activity in scleroderma patients.

Inclusion Criteria:

• Scleroderma (SSc) participants must have been diagnosed with SSc as defined by the American College of Rheumatology within the past 2-5 years AND fulfill criteria for diffuse cutaneous SSc according to LeRoy classification
• Healthy controls must be free of SSc or other autoimmune disease and have no known skin pathology

Exclusion Criteria:

• Diagnosis of skin malignancy within the previous 2 years, excluding adequately treated squamous cell skin cancer, basal cell carcinoma, and carcinoma in situ.
• Presence of wounds or skin rashes at the site of Spatial frequency domain imaging (SFDI) measurement or skin biopsy
• Presence of other co-morbid illnesses with an estimated median life expectancy < 5 years.

Exclusion criteria for providing a skin biopsy sample during the study but are not exclusions for enrollment in the study.

• Subject has known allergy to lidocaine or has had a reaction to local anesthetics in the past will not provide skin biopsy samples at any time during the study.
• Subjects who, in the opinion of the investigator, are high-risk for small tissue calcification, or other conditions that may affect wound healing will not provide skin biopsy samples at any time during the study.
• Subjects who are pregnant or lactating are excluded from providing a skin biopsy sample only while they are pregnant or lactating.