Sarcoidosis and Small-fiber Neuropathy

Abstract

Chronic pain is one of the most commonly reported symptoms among sarcoidosis patients. Not only does it significantly affect quality of life, but it also is a source of frustration for both the patient and physician because the etiology for pain often is unknown. Although patients typically complain of neuropathic-type pain, nerve conduction studies and other conventional diagnostic procedures frequently fail to reveal objective evidence of neurologic disease. However, in recent years, the growing use of specialized tests such as skin biopsy and sudomotor testing has helped to establish the diagnosis of small-fiber neuropathy as the cause of pain in these patients via objective and quantifiable means. Management of sarcoidosis small-fiber neuropathy should consist of target-directed treatment of the underlying disease and appropriate symptomatic therapy.

Physical activity and training in sarcoidosis: review and experience-based recommendations

“…Since symptoms of SFN are disabling for patients, they can also significantly reduce their health status [64][65][66]. To date, SFN itself is often difficult to treat [10,67].…”

Neurological Symptoms of Sarcoidosis-induced Small Fiber Neuropathy Effectively Relieved with High-dose Steroid Pulse Therapy

“…Neurological complications in sarcoidosis patients are well described, and the prevalence of clinical involvement of the nervous system, such as cranial nerve dysfunction and neuropathy of large fibers, is estimated to be approximately 5% (9)(10)(11)(12). Recently, SFN has also been increasingly recognized to be a more common condition in sarcoidosis patients, as Hoitsma et al reported that 31 of 70 patients (44%) with chronic severe sarcoidosis have SFN (4).…”

“…With regard to treatment for SFN, no studies published to date have shown steroids and/or methotrexate to be effective against sarcoidosis-induced SFN; rather, several studies have indicated that these drugs are not beneficial (12,15,16). A few reports have demonstrated anti-TNF-α agents (15), high-dose intravenous immunoglobulin (IVIG) (16) and ARA 290 (an erythropoietin derivative) (17) to be effective treatments for SFN.…”

“…In contrast, the precise etiology of axon loss associated with sarcoidosis-induced SFN has yet to be fully clarified (12). Microangiopathy not due to granuloma formation is considered to be a possible cause (12,(20)(21)(22).…”

“…In contrast, the precise etiology of axon loss associated with sarcoidosis-induced SFN has yet to be fully clarified (12). Microangiopathy not due to granuloma formation is considered to be a possible cause (12,(20)(21)(22). Additionally, the involvement of signaling molecules (e.g., TNF-α) and immune-mediated mechanisms involving circulating immune complexes and autoantibodies has been postulated to be related to the development of sarcoidosis-induced SFN (15,16).…”