Clinical characteristics of patients with myalgia as the initial manifestation of small and medium-sized vasculitis: a retrospective study

Abstract

Myalgia is a common symptom in small and medium-sized systemic vasculitis, sometimes occurring as the initial or only clinical manifestation of vasculitis. This study investigated the clinical features and diagnostic process in patients presenting with myalgia as the initial symptom of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) or polyarteritis nodosa (PAN). We included 93 patients diagnosed with AAV or PAN by retrospectively reviewing their clinical records at initial diagnosis. Clinical findings and diagnostic methods were assessed in patients with myalgia. Of 93 patients, myalgia was observed in 21 (22.6%) patients, with diagnostic classifications of microscopic polyangiitis (MPA) in 12 (52.4%), granulomatosis with polyangiitis in 2 (9.5%), eosinophilic granulomatosis with polyangiitis in 2 (9.5%), and PAN in 5 (23.8%). Myalgia was present in the lower extremities of all patients; more than 80% of patients had pain in the calf muscle. In 10 patients with myalgia, including 7 with MPA and 3 with PAN, muscle biopsy was performed because myalgia was the main symptom and no other impaired organs were suitable for biopsy. Consequently, 8 patients had necrotizing vasculitis, leading to MPA or PAN diagnosis, although muscle pathology was not evaluated in patients without myalgia. Muscle magnetic resonance imaging was useful in determining the biopsy site. Myalgia, especially in the lower limbs, may be an initial clinical sign of vasculitis, particularly in MPA or PAN patients. Moreover, the histological evidence of muscular vasculitis can contribute to a definite diagnosis especially in patients presenting with myalgia as an early symptom 3 of AAV or PAN.

The "Ant-farm"-like Appearance of Restricted Lower Limb Vasculitis on Fluorodeoxyglucose-positron Emission Tomography

“…The MRI findings are applied to an auxiliary diagnosis and utilized to determine an appropriate site for a muscle biopsy ( 2 , 3 ). In our patients, histological analyses revealed edematous changes in the muscle caused by the infiltration of inflammatory cells in the arterial walls in Cases 1 and 2, which coincides with the previously reported findings of muscular vasculitis ( 5 ). In addition, the MRI findings of the three patients were compatible with those of vasculitis in the muscles.…”

“…Histological analyses of the affected muscles revealed leukocyte infiltration into the vessel walls ( 4 ). These findings are distinct from those of inflammatory myositis, which is characterized by necrosis or inflammatory destruction of muscle fibers ( 5 ). Thus, restricted lower limb vasculitis has a different etiology from that of inflammatory myositis.…”

“…Muscles, especially in the lower limbs, have been reported to be target organs for localized vasculitis (1). Muscle vasculitis limited to the lower limbs has been referred to as restricted lower limb vasculitis (2)(3)(4)(5). However, this disease is yet to be widely recognized, and effective diagnostic methods have not been established.…”

Classification for Staging and Managing Patients with Biopolymer-induced Human Adjuvant Disease

“…Petechiae was the only clinical sign with 100% sensitivity. 15,16 In the same way, PPVs were good in patients with eczema and pachydermostosis; finally, memory loss, dry mouth, presence of nodules, and necrosis were favorable, ruling out the disease in their absence due to NPV greater than 80% (Table 9).…”

“…Taking into account the frequencies of the appearance of each of the signs and symptoms, location of the biopolymers in different planes, and pathophysiology of the clinical behavior of the disease, the Pachón classification proposes taking five parameters into consideration: (1) diagnostic imaging findings (MRI), (2) local clinical signs, (3) systemic symptoms, (4) systemic clinical signs, and (5) autoimmune markers (Table 5). [8][9][10][11][12][13][14][15] This assessment makes it possible to generate a score that categorizes the biopolymer carrier patient with a stage of the disease (mild, moderate, or severe), which in turn allows us to establish an individualized treatment plan (Tables 6, 7).…”