A 53 yo F with past medical history of diabetes and hypothyroidism presents with:
- 4 month history of weakness
- Fatigue with washing her hair
- Needs help with changing her clothes
- Difficulty climbing stairs
- Dysphagia, weight loss, and low grade fevers
Physical Exam
- 3/5 strength of shoulder abduction, 4/5 strength of hip flexion, 5/5 strength otherwise
- Erythematous rash anterior chest/neck/posterior shoulders (view image), erythematous rash and nodules over MCPs (view image)
- Purplish rash over eyelids (view image)
Diagnostic Workup
- Labs: CK 13,000, AST 350, ALT 425, Cr 0.34, ESR 35, TSH wnl, ANA pos
- EMG: increased insertional activity with spontaneous fibrillations, c/w myopathic pattern
- Femur MRI: muscle edema of psoas, rectus femoris, and vastus lateralis muscles
Next Steps & Treatment
Prior to referral, other workup can be initiated:
- Lab workup for myositis specific antibodies and myositis associated antibody panel (ENA, extended myositis panel)
- Referral for muscle biopsy (biopsy side contralateral to EMG)
- Assess for pulmonary involvement
- HRCT of lung
- PFTs with DLCO
- TTE or ECG, if concern for cardiac involvement
- Evaluation for underlying malignancy
- Age appropriate screening: mammogram, colonoscopy, pelvic exam/PAP
- CXR if history of smoking
- Remember: presence of >1 high-risk feature (i.e., anti-TIF/anti NXP2, >40 yo, dysphagia, cutaneous necrosis) -> consider CT chest/abdomen/pelvis +/- upper/lower endoscopies, in addition to age appropriate screening
Other Considerations
- What if this patient did not have any muscle weakness?
- Consider clinically amyopathic dermatomyositis (CADM)
- These patients can still have ILD, mild CK elevations
- What if this patient presented with mechanic’s hands (view image), significant shortness of breath, fevers, and Raynaud’s?
- Consider antisynthetase syndrome, a form of inflammatory myositis