Digital ulcers (DUs) in scleroderma result from recurrent Raynaud's phenomenon (RP) and microtrauma with high impact on quality of life, management of DUs is a great challenge for clinicians. Medical use of ozone (triatomic oxygen) was initiated in the 19th century. Ozone has multiple therapeutic effects in wound healing due to the property of releasing nascent oxygen, which has been shown to stimulate antioxidant enzymes.

Digital ulcers (DUs) in scleroderma result from recurrent Raynaud's phenomenon (RP) and microtrauma with high impact on quality of life, management of DUs is a great challenge for clinicians. Medical use of ozone (triatomic oxygen) was initiated in the 19th century. Ozone has multiple therapeutic effects in wound healing due to the property of releasing nascent oxygen, which has been shown to stimulate antioxidant enzymes, we aim to assess the effects of ozone therapy on the healing in Scleroderma DUs and the expressions of vascular endothelial growth factor (VEGF), and endothelin-1 type A receptor (ETAR) and angiotensin II type 1 receptor (AT1R) autoantibodies level in the wounds after treatment.

Inclusion Criteria:

• systemic sclerosis patients with DUs fulfilling ACR/EULAR criteria for diagnosis 2013

Exclusion Criteria:

• calcinosis ulcer traumatic ulcer vasculitis