TY  - JOUR
A1  - Jänsch, Sarah
A1  - Evdokimov, Dimitar
A1  - Egenolf, Nadine
A1  - Meyer zu Altenschildesche, Caren
A1  - Kreß, Luisa
A1  - Üçeyler, Nurcan
T1  - Distinguishing fibromyalgia syndrome from small fiber neuropathy: a clinical guide
JF  - Pain Reports
N2  - Introduction: 
Fibromyalgia syndrome (FMS) and small fiber neuropathy (SFN) are distinct pain conditions that share commonalities and may be challenging as for differential diagnosis.

Objective: 
To comprehensively investigate clinical characteristics of women with FMS and SFN to determine clinically applicable parameters for differentiation.

Methods: 
We retrospectively analyzed medical records of 158 women with FMS and 53 with SFN focusing on pain-specific medical and family history, accompanying symptoms, additional diseases, and treatment. We investigated data obtained using standardized pain, depression, and anxiety questionnaires. We further analyzed test results and findings obtained in standardized small fiber tests.

Results: 
FMS patients were on average ten years younger at symptom onset, described higher pain intensities requiring frequent change of pharmaceutics, and reported generalized pain compared to SFN. Pain in FMS was accompanied by irritable bowel or sleep disturbances, and in SFN by paresthesias, numbness, and impaired glucose metabolism (P < 0.01 each). Family history was informative for chronic pain and affective disorders in FMS (P < 0.001) and for neurological disorders in SFN patients (P < 0.001). Small fiber pathology in terms of skin denervation and/or thermal sensory threshold elevation was present in 110/158 (69.7 %) FMS patients and 39/53 (73.6 %) SFN patients. FMS patients mainly showed proximally reduced skin innervation and higher corneal nerve branch densities (p<0.001) whereas SFN patients were characterized by reduced cold detection and prolonged electrical A-delta conduction latencies (P < 0.05).

Conclusions: 
Our data show that FMS and SFN differ substantially. Detailed pain, drug and family history, investigating blood glucose metabolism, and applying differential small fiber tests may help to improve diagnostic differentiation and targeted therapy.
KW  - fibromyalgia syndrome
KW  - small fiber neuropathy
KW  - clinical phenotype
KW  - pain pattern
KW  - differential diagnosis
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350306
VL  - 9
IS  - 1
ER  -