Muscular vasculitis confined to lower limbs: description of two case reports and a review of the literature

Abstract

Muscular involvement is common during systemic vasculitides, such as polyarteritis nodosa. However, in rare cases, muscular involvement can be the only clinically evident feature of the disease. The clinical pattern of isolated muscular vasculitis may mimic several other inflammatory muscle disorders, such as idiopathic inflammatory myositis, and may represent a challenge in differential diagnosis. Herewith, we present two clinical cases as examples of peculiar clinical and histopathological characteristics of isolated muscular vasculitis. Our patients were successfully treated with steroids and immunosuppressive agents. Moreover, we provide a review of the recent existing medical literature. Our cases suggest the importance of performing muscle biopsy in patients with muscular symptoms to guide the diagnosis and the treatment.

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

“…Muscle biopsy was performed in patients with myalgia who lacked a suitable visceral impairment site for biopsy, as well as a lower BVAS than other patients, suggesting that muscle biopsy would be useful as a definite diagnostic procedure even in the early phase of SVV and MVV. Muscular impairments of the lower limbs have been described as a localized and/or initial symptom of PAN [5,13,14], whereas the present study demonstrated that muscular vasculitis in the lower limbs could be a crucial early indication of MPA. To the best of our knowledge, only three cases of AAV have been reported in which muscular symptoms were the initial and main manifestation of disease and whereby definite diagnosis was made by muscle biopsy [15][16][17].…”

“…This supported that myalgia, similar to arthritis, may occur as the initial manifestation of PSV and that they may co-manifest [4]. Cases with muscular manifestations in the lower extremities, typically of the calf muscle, have been reported as muscular vasculitis related to PAN or PAN-mimicking disorders [5][6][7][8][9]13,14]. In our series of 21 patients with myalgia, the lower extremities were involved in all of them, and calf muscle pain was demonstrated in more than 80% of patients.…”

“…The sensitivity of muscle biopsy for the diagnosis of necrotizing vasculitis has been widely described to range between 33-88% in patients with PSV [18][19][20]. In our patients, the biopsy site was determined based on the MRI findings, as signal changes are useful for screening the presence of vasculitis [13,14,21]. Thus, muscle MRI may increase diagnostic sensitivity by acting as a guide for selection of the biopsy site.…”

“…In addition, we demonstrated the absence of serum aldolase elevation in patients presenting with normal levels of serum CK, supporting this pathological mechanism. Meanwhile, typical necrotizing vasculitis is not always correlated with abnormal MRI signals [13,14]. Indeed, non-necrotizing vasculitis localized in the calf muscle has also been reported as PAN-like vasculitis [14], and the incidence of typical necrotizing vasculitis has been found to be 50% in AAV or PAN patients presenting with muscular vasculitis [18].…”

Cutaneous arteritis with compartment syndrome: Case report and review of published works

“…We searched for case reports describing cases with both skin lesions and muscle disorders based on biopsy or medical imaging, and found five cases, including the case presented here (Table 1). [11][12][13][14] All cases had swelling, and we considered that the presence of swelling might be useful for differential diagnoses between CA with and without muscle disorders. Oral steroid therapy was not effective in two cases, including our case, and four cases, including our case, required immunosuppressants or intravenous methylprednisolone pulse therapy.…”