Very few studies have evaluated the prevalence of small fiber neuropathy (SFN) during pathologies that may be responsible for small fibers damage.

SUDOSCAN is a new rapid (2 minutes), automated, reproducible and non-invasive technology to assess small fiber neuropathy by sweat function.

With quantitative and reproducible results, SUDOSCAN allows physicians to early detect and follow-up peripheral neuropathy to monitor disease progression and assess treatment efficacy for a better patient management.

SUDOSCAN® could allow the identification of SFN in painful patients apart from another pathology already diagnosed responsible for SFN.

The purpose of the study SUDOCU is to assess the prevalence of small fiber neuropathies (SFN) in patients with systemic autoimmune pathologies or unexplained pain syndrome.

Inclusion Criteria:

• Patient corresponding to one of the two following groups:

  1. Systemic autoimmune pathology known to be complicated by small fiber neuropathies.

     The following autoimmune pathologies will be included: Lupus, Sjogren, Scleroderma, Myositis, rheumatoid arthritis, Sarcoidosis, Vasculitis of small or medium vessels

  2. No conditions known to be responsible at SFN, unexplained pain symptoms

• Aged ≥ 18 years

• Having given free and informed written consent

Exclusion Criteria:

• Chronic alcoholism
• Unbalanced diabetes
• Chemotherapies
• HIV
• Vitamins B12, B1, B6 deficiencies