A 19-year-old girl was referred with diffuse pain in her left shoulder for a week. No history of trauma was reported. No ecchymosis or bruising was observed. Crohn’s disease was reported from clinical history, in remission, without any medication administered for the last 2 years. MR imaging was suggested.
MR imaging was performed with a 1.5 Tesla scanner using standard sequences. The fat suppressed oblique coronal PD-w (Fig. 1) and the fat suppressed oblique sagittal T2-w MR images (Fig. 2, 3), showed high signal intensity in the superior part of the deltoid and supraspinatus muscles as well as in the short head of the biceps muscle.
A. Inflammatory bowel disease has been associated with extraintestinal manifestations [1]. Musculoskeletal involvement is a common extraintestinal manifestation, occurring in 6-46% of patients [2]. It has been reported that inflammatory myositis is associated more frequently with Crohn’s disease than with ulcerative colitis [3]. Pathophysiology of myositis is not clearly understood but a common immunologic pathogenesis of these two entities has been suggested [2]. There are studies suggesting that various infectious agents, like measle virus or herpes virus, could initiate the production of auto-antibodies, which could induce myositis. Others suggest that the therapy of inflammatory bowel disease with steroids or azathioprine could induce myositis [3].
B. Symptoms of myositis are not specific. Patients usually present with muscle stiffness and myalgia. In addition, swelling, warmth, localised tenderness and painful joints have been reported. Laboratory examinations are usually normal [2]. Increased CPK could be observed [4]. Diagnosis is challenging due to the lack of history of trauma or clinical indication for infection. MR imaging is required in order to rule out other disorders and to depict oedema within the involved muscles.
C. Plain radiographs are useful to rule out fractures or space-occupying lesions. MR imaging is able to depict soft tissue disorders due to its inherent high contrast resolution. Thus, oedema within the muscles is accurately disclosed with fluid sensitive sequences. Muscular oedema and the clinical history of inflammatory bowel disease lead to proper diagnosis. Muscle biopsy is the gold standard for final diagnosis [2].
D. Treatment is conservative aiming to relieve the symptoms and the prognosis is very good. MR imaging is able to monitor response to treatment by means of evaluating the regression of oedema. In case that the patient is already treated for Crohn’s disease, resolution of myositis may be observed. Our patient received Prednisolone for 10 days. The 20-days clinical follow up revealed no symptoms and signs.
E. A patient with Crohn’s disease could rarely develop myositis as a result of extraintestinal manifestations of the disease.
Myositis related to Crohn’s disease
This is a 19-year-old female patient presenting with diffuse pain in the left shoulder for about one week. There is no history of trauma, no obvious subcutaneous bruising, or skin changes. Her past medical history includes Crohn's disease, which has been in remission for 2 years, and she has not been on any medication.
Based on the MRI images of the shoulder joint provided:
In summary, the most prominent feature is diffuse edema signal in the soft tissue around the shoulder.
Taking into account the patient’s history of Crohn’s disease, the MRI evidence of significant muscle edema, and the lack of trauma factors, the most likely diagnosis is inflammatory myositis (myositic lesion) related to Crohn's disease. In the absence of classic clinical symptoms or a history of injury, such myositis often requires imaging findings and further tests (e.g., muscle enzyme studies, biopsy) to exclude other causes.
After acute inflammation is controlled, rehabilitation exercises can be gradually introduced to restore shoulder joint range of motion, strength, and function. An individualized and stepwise approach is recommended under the guidance of a rehabilitation specialist or physician. Below is an example:
If the patient has other underlying issues, such as osteoporosis or limited cardiopulmonary function, the intensity must be carefully controlled and supervised by qualified medical personnel.
This report is provided as a reference based on available imaging and medical history and cannot replace an in-person consultation or a formal diagnosis and treatment plan by a professional physician. For specific diagnosis, treatment, and rehabilitation, please consult a specialist and follow the guidance of a rehabilitation therapist.
Myositis related to Crohn’s disease
