Eligibility Criteria:
Inclusion Criteria:
Healthy Volunteers:
* Age of at least 18 years
* Existence of a contraceptive method for women of child-bearing age
* Person affiliated to social security or beneficiary of such a scheme
* Signed consent form
Systemic sclerosis patients:
* Systemic sclerosis meeting the EULAR criteria.
* Presence of 1 ischemic digital cutaneous ulceration , with digital ulcer classified as "active ulcers" according to the North American working group definition: epithelial denudation is clearly Visible at one place and the bed of de-epithelialized ulcer can be seen; Ulcerations distal to the proximal interphalangeal joint, not associated with calcinosis or bony relief.
* Ulcers whose major axis measured with the electronic caliper is ≥ 2 mm
* Age greater than or equal to 18 years
* Existence of a contraceptive method for women of reproductive age
* A person who is or is a beneficiary of social security
* Informed and signed consent signed by the patient or his / her legal representative.
Exclusion Criteria:
Healthy Volunteers
* Treprostinil contraindications: Known hypersensitivity to treprostinil or any of the excipients, Pulmonary arterial hypertension related to veno-occlusive disease, Congestive heart failure due to severe left ventricular dysfunction, Severe hepatic insufficiency (Child-Pugh stage C), Evolving gastrointestinal ulcer, intracranial hemorrhage, recent trauma or other clinical condition that may lead to bleeding, Congenital or acquired valvular abnormalities with cardiac repercussions, Severe ischemic heart disease or unstable angina; Myocardial infarction in the last six months; Decompensated cardiac insufficiency not medically controlled; Severe arrhythmias; Cerebrovascular lesions (such as transient ischemic attack, stroke) that occurred within the last three months.
* Persons referred to in Articles L1121-5 to L1121-8 of the French Public health Code: pregnant woman, parturient, nursing mother, person deprived of liberty by judicial or administrative decision, person subject to a legal protection measure, can not Be included in clinical trials.
* Subject in an exclusion period from another study,
* Subject who would receive more than 4500 euros of compensation due to his participation in other biomedical research in the 12 months preceding this study
Systemic sclerosis patients:
* Iloprost cure carried out in the previous month or planned in the following month.
* Initiation or change of dosage of bosentan, sildenafil or calcium channel blockers in the previous month or in the following month
* Digital Sympathectomy or botulinum toxin injection planned in the following month.
* Clinically superinfected digital ulcers
* Treprostinil contraindications: Known hypersensitivity to treprostinil or any of the excipients, Pulmonary arterial hypertension related to veno-occlusive disease, Congestive heart failure due to severe left ventricular dysfunction, Severe hepatic insufficiency (Child-Pugh stage C), Evolving gastrointestinal ulcer, intracranial hemorrhage, recent trauma or other clinical condition that may lead to bleeding, Congenital or acquired valvular abnormalities with cardiac repercussions, Severe ischemic heart disease or unstable angina; Myocardial infarction in the last six months; Decompensated cardiac insufficiency not medically controlled; Severe arrhythmias; Cerebrovascular lesions (such as transient ischemic attack, stroke) that occurred within the last three months.
* Persons referred to in Articles L1121-5 to L1121-8 of the French Public health Code: pregnant woman, parturient, nursing mother, person deprived of liberty by judicial or administrative decision, person subject to a legal protection measure, can not Be included in clinical trials.
* Subject in an exclusion period from another study,
* Subject who would receive more than 4500 euros of compensation due to his participation in other biomedical research in the 12 months preceding this study