Digital Ulcers (DEs), are painful open sores on the fingers and toes and are due to limited perfusion of blood vessels in patients with Scleroderma. In particular, ulcers are caused by narrowing of the arteries, resulting in reduced blood supply to the fingers, causing pain and difficult to heal leaving deep scars. DEs may be present on the rails or fingertips, on the extensor surfaces of the joints, and depending on the underlying calcification. The etiology of ulcers is multifactorial. Raynaud's ischemia, sclerosis, dry skin, calcification and local trauma can all contribute to the onset of Digital Ulcers. Spontaneous fissures or ruptures can also develop into ulcers in patients with scleroderma and severe Raynaud's disease. Whatever the reason for their appearance, DEs negatively affect the quality of life of patients as they complicate even simple daily activities, while they can lead to serious complications such as osteomyelitis or other serious soft tissue infections, up to amputation. Over the last decade, in several randomized clinical trials, DEs have been studied in detail, which are defined or classified differently in each case. The clinical treatment of patients with DE would be facilitated by the availability of specific criteria for the classification of DE. Internationally, the classification of pressure ulcers is usually followed, but this classification is not sufficient for all types of DE observed in Scleroderma. The lack of a clear classification of DEs prompted researchers to evaluate the frequency and morphology of lesions, their characteristics, their physical course, and their healing time in groups of patients with Scleroderma. In a recent study, three categories of classification of digital ulcers based on the patient's clinical picture were proposed by the UK Scleroderma Study Group (UKSSG).

1. Digital Ulcers: Lesions (on the fingers or peripheral to the metacarpophalangeal joint), with loss of surface epithelialization and visually distinct depth. The ulcer substrate is often superficially liquid with a scaly surface. The damaged skin surrounding the DE is not unusually erythematous and / or impregnated (absence of additional infection). Also, DE often has an overlying crust and patients report severe pain. The most common signs of DE are the fingertips and over the extensor muscle of the (dorsal / back) fold of the hands in relation to subcutaneous calcification. Less commonly, DEs may occur in other places on the hands, such as above the lateral folds of the fingers and at the base of the nail.
2. Healed Ulcer: Damage with complete surface epithelialization (in any other case it will be classified as DE).
3. No Ulcer: Any lesions that do not meet the definitions of either DEs or healed DEs, including (not only) phalangeal pitting scars, hyperkeratosis and fissures.

In general, targeted future research is needed to improve the reliability of the clinical evaluation of Finger Ulcers for their treatment and to optimize the quality of life of patients.

Systemic Sclerosis Criteria (Scleroderma) In 1980, the American College of Rheumatology (ACR), in conjunction with the European League Against Rheumatism (EULAR), defined the classification criteria for Systemic Sclerosis / Scleroderma. Due to the lack of sensitivity in locating the early stages of Scleroderma and especially the limited cutaneous Systemic Scleroderma, the classification criteria were revised in 2013. It has been found that the thickening of the skin of the fingers that extends near the metacarpophalangeal joints is sufficient to classify the patient with Scleroderma, if this is not obvious, seven additional elements apply, each with a different severity. Specifically, the data are: thickening of the skin of the fingers, finger lesions, teleangiectasia, abnormal capillaries, interstitial pneumonia or Pulmonary Arterial Hypertension, Raynaud's phenomenon and autoantibodies associated with All cases of patients with Scleroderma according to the ACR criteria of 1980 were also classified with Scleroderma and the new criteria of 2013, where several additional cases of patients with Systemic Sclerosis were added.

Inclusion Criteria:

• Adult patients
• Patients diagnosed with scleroderma (diffuse or limited)
• Patients with at least one digital ulcer, whether or not it is due to scleroderma
• Patients with 2013 ACR / EULAR Classification Criteria with a total score of ≥ 9
• Patients already taking Bosentan (Klimurtan®)
• Patients who will sign the consent form for their participation in the study

Exclusion Criteria:

• Patients with digital ulcers of other etiology, other than scleroderma
• Patients with severe pulmonary arterial hypertension (severe PAH- Category 3-4 according to WHO)
• Patients who do not meet the criteria for taking the study drug, according to the Summary of Product Characteristics

Adult patients who have been diagnosed with scleroderma (both types:diffuse or limited) and at least one digital ulcer. These patients have been categorised with a total score of ≥ 9 according to 2013 ACR / EULAR Classification Criteria. Regarding current treatment sceme theya are already taking Bosentan (Klimurtan®)