[Academic Presentation] A Case of Systemic Scleroderma with Rhabdomyolysis

Clinical Data

Patient, female, 49 years old. She has experienced progressive swelling and hardening of the skin on her face and both forearms for more than one month. One month ago, without any apparent precipitating factors, the skin on her face and both forearms became hardened, difficult to pinch, with a dry surface and waxy sheen. Following exposure to cold, her hands exhibited pallor, cyanosis, and erythema, accompanied by intermittent muscle pain in both lower legs, bilateral elbow joint pain, pruritus, and occasional dry cough without sputum. She also reported mild dyspnea and chest tightness during vigorous activity, but had not received any treatment. The patient denied dysphagia, fever, abdominal pain, or diarrhea. Physical examination revealed stable vital signs; no abnormalities were noted on cardiac, pulmonary, or abdominal examination; joints showed no deformity or swelling; bilateral fist clenching was mildly restricted; squatting was unimpeded; and shoulder abduction was unrestricted. Tenderness was present over both knees and the right elbow. Dermatological findings included swelling of the skin on both forearms and the face, with a smooth, waxy‑appearing surface that felt firm and resistant to pinching. Skin temperature was reduced in both hands and feet; small patchy dark red macules and ecchymoses were observed on the fingers. Prominent areas of hypopigmentation and hyperpigmentation were noted in the anterior neck region. Routine blood tests, urinalysis, liver and kidney function, electrolytes, cardiac enzyme panel, coagulation profile, complete immunologic workup, blood transfusion screening, and electrocardiogram all showed no significant abnormalities. ANA was positive at 1:320, with a coarse granular pattern; RNP/Sm was positive, as was Sm. Chest CT demonstrated interstitial lung inflammation with mediastinal lymphadenopathy, calcification of the right hilar lymph nodes, and aortic calcification. Skin biopsy pathology confirmed features consistent with scleroderma. Diagnosis: ① Systemic sclerosis; ② Interstitial pneumonia. Treatment course: Methylprednisolone 60 mg/day was administered, along with symptomatic management including potassium and calcium supplementation, gastroprotective therapy, anti‑infective therapy (cefoperazone/sulbactam), circulation‑promoting and stasis‑resolving agents (ginkgo damo injection and heparin ointment), and supportive care (intravenous infusion of thin‑grain peptide, oral vitamin E capsules, topical vitamin E cream). The patient’s condition remained stable; skin temperature in the hands and feet improved compared with baseline, dark red macules and ecchymoses on the fingers faded, and the skin of both forearms and the face became softer. Two days ago, the patient suddenly developed severe epigastric pain, paroxysmal in nature, radiating to the back, accompanied by subjective dyspnea. Electrocardiographic evaluation revealed: BP 197/114 mmHg, heart rate 114 beats/min, respiratory rate 28 breaths/min, oxygen saturation 90–100%, and random finger glucose 6.6 mmol/L. The patient was alert and oriented, with regular heart rhythm and no appreciable murmurs. Lung sounds were coarse bilaterally; marked tenderness was noted below the costal margins and xiphoid process in the epigastrium, without rebound tenderness; abdominal muscles were slightly tense; the skin throughout the body was profusely sweaty; distal extremities were cool; physiological reflexes were intact, while pathological reflexes were absent. Bedside ECG showed no abnormalities. Thoracoabdominal CTA revealed no evidence of aortic dissection; slight calcification of the aortic arch; mild thickening of the abdominal aortic wall suggestive of early atherosclerosis; interstitial changes in both lungs with minor infection; small pleural effusions on both sides; incomplete expansion of the lower lobes of both lungs; calcified foci in the lower lobes; enlarged mediastinal lymph nodes; and a slightly hyperdense lesion within the lumen of the lower esophagus. Further investigations disclosed fatty liver, with strip‑like enhancement beneath the capsule of the right lobe and low‑density areas in the right lobe; minimal pelvic fluid accumulation on abdominal imaging. Plain abdominal radiography showed scattered intestinal gas, which was dynamically monitored. Emergency blood tests showed WBC 14.51 × 10^9/L, neutrophils 88.7%; RBC 5.73 × 10^12/L; Hb 172.0 g/L; platelets 396.0 × 10^9/L; NT‑proBNP 325 pg/mL; and normal results for cardiac enzymes, pancreatic injury markers, DIC workup, liver and kidney function, and electrolytes. The patient was immediately placed under critical care status, receiving continuous supplemental oxygen, nitroprusside infusion to control blood pressure, diclofenac suppositories, and 654‑2 for analgesia and spasmolysis. Blood pressure gradually stabilized, but pain persisted unabated. After consultation with the Department of Internal Medicine, morphine was administered under close monitoring, providing temporary relief. However, the patient continued to report generalized soreness and weakness. A repeat cardiac enzyme panel revealed CK 9828 U/L, LDH 568 U/L, AST 227 U/L, ALT 88 U/L; highly sensitive cardiac troponin 32.8 pg/mL; myoglobin >1200 ng/mL; and CK‑MB isoenzyme 183.9 ng/mL. Neurological consultation suggested rhabdomyolysis, prompting transfer to the Department of Neurology for further management. Upon admission to neurology, the patient exhibited markedly decreased muscle strength—grade 3 in both upper limbs and grade 2 in both lower limbs—with normal muscle tone and intact deep and superficial sensation. Urinalysis showed soy sauce‑colored urine, with hematuria (+++), pyuria (+), nitrite (+), proteinuria (++), specific gravity >1.030, glucose (+), ketones (+), urobilinogen (++), red blood cell count 529.5/μL, white blood cell count 70.70/μL, epithelial cell count 58.5/μL, small round epithelial cells (+), and pathological casts counted at 1.0/μL. Antibody testing for dermatomyositis was negative; creatine kinase exceeded 20,000 U/L, and lactate dehydrogenase reached 1,863 U/L, supporting the diagnosis of rhabdomyolysis. High‑dose glucocorticoid pulse therapy was initiated (methylprednisolone 1,000 mg/day for 3 days → 500 mg/day for 3 days → 240 mg/day for 3 days → 120 mg/day for 3 days → 80 mg/day for 3 days → oral prednisone acetate 40 mg/day); immunosuppressive therapy with methotrexate 10 mg/week; alkalinization of urine using 5% sodium bicarbonate solution; blood pressure control via antihypertensive pump; and hepatoprotective measures including polyene phosphatidylcholine, glycyrrhizic acid, and reduced glutathione. Symptomatic supportive care was provided. The patient’s limb pain and weakness improved significantly; muscle strength in both upper and lower limbs recovered to grade 3; urine became clear; follow-up creatine kinase was 487 U/L, myoglobin 99.7 ng/mL, CK‑MB isoenzyme 4.3 ng/mL; transaminases were normal, with ALT at 75 U/L; hematuria (+++), proteinuria (+), red blood cell count 316.6/μL, epithelial cell count 58.5/μL—all normalized; nitrite, glucose, ketones, urobilinogen, small round epithelial cells, and pathological casts all tested negative. The patient was discharged in improved condition.
 

Discussion

Systemic sclerosis (SSc) is a systemic autoimmune connective tissue disease characterized primarily by skin sclerosis and fibrosis of internal organs, with high morbidity and mortality rates. At present, the etiology and pathogenesis of SSc remain unclear; most researchers attribute it to the combined effects of genetic and environmental factors. Immune dysregulation, inflammatory responses, vascular abnormalities, and aberrant collagen synthesis all play critical roles in the onset and progression of SSc. Rhabdomyolysis is a condition resulting from skeletal muscle cell injury caused by various etiologies, leading to the release of intracellular contents—such as myoglobin, creatine kinase, aldolase, lactate dehydrogenase, and electrolytes—into the bloodstream. This can precipitate severe metabolic disturbances, acute renal failure, and even disseminated intravascular coagulation. The causes of rhabdomyolysis are diverse, including muscular trauma (e.g., excessive exercise, crush injuries, overuse, or seizures), inadequate perfusion, heatstroke, electrolyte imbalances (e.g., hypokalemia, hypophosphatemia), alcohol consumption, infections, certain medications (e.g., statins, morphine, caffeine, chlorpromazine, amphetamines), as well as hereditary, metabolic, and autoimmune disorders. Clinically, patients may present with muscle pain, weakness, dark urine, tenderness, swelling, nausea, vomiting, and even pressure‑induced skin necrosis; however, fewer than 10% of cases exhibit these classic symptoms. In this case, a patient undergoing treatment for systemic sclerosis experienced sudden, severe substernal pain that failed to respond to nonsteroidal anti‑inflammatory analgesics or spasmolytics. Concurrently, there was an abrupt rise in blood pressure and a marked tachycardia, yet no obvious muscle pain was noted. Urgent laboratory tests revealed normal levels of serum myoglobin, CK, CK‑MB, and amylase, and the urine remained clear; thus, rhabdomyolysis was not initially suspected. Abdominal plain radiography, abdominal ultrasonography, and thoracoabdominal CTA were performed, ruling out intra‑abdominal organ perforation, pancreatitis, aortic dissection, and other potential causes. Symptomatic management focused on antihypertensive and analgesic therapies, but the patient’s symptoms showed little improvement. Subsequently, repeated serial testing demonstrated persistently elevated CK and serum myoglobin levels, and the patient gradually developed muscle pain and weakness accompanied by progressively darker urine.

Diagnostic criteria for rhabdomyolysis:

① Presence of myalgia, muscle weakness, and other symptoms; ② Creatine kinase (CK) levels exceeding the upper limit of normal by tenfold; ③ Electromyography demonstrating myogenic damage; ④ Muscle biopsy revealing nonspecific inflammatory changes; ⑤ Myoglobinuria. Among these findings, elevated CK is the most specific diagnostic indicator for rhabdomyolysis; a CK level more than ten times the upper limit of normal, in combination with myoglobinuria and exclusion of myocardial infarction, is diagnostically significant for rhabdomyolysis. In this case, the patient’s serum CK exceeded 20,000 U/L, confirming the diagnosis of rhabdomyolysis. There is no specific treatment for rhabdomyolysis; management focuses on addressing the underlying cause, avoiding nephrotoxic drugs, and employing fluid therapy and urinary alkalinization. In severe cases or when complications are serious, renal replacement therapy may be indicated. Prior to the onset of rhabdomyolysis, this patient had no precipitating factors such as muscle trauma, electrolyte disturbances, or infection. Given the patient’s history of systemic sclerosis and relevant laboratory findings, an autoimmune etiology was considered. Although there have been no reported cases of rhabdomyolysis associated with systemic sclerosis, Zhang Lei published a 2008 analysis of the clinical characteristics of 25 cases of rhabdomyolysis, in which autoimmune myositis accounted for 12% of cases. Accordingly, it is plausible that the rhabdomyolysis in this patient may also be related to underlying autoimmune responses associated with systemic sclerosis, thereby triggering the condition. During treatment, in addition to standard measures, high-dose corticosteroid pulse therapy combined with immunosuppressive agents yielded favorable outcomes, further supporting this hypothesis. Rhabdomyolysis carries grave consequences, with high rates of disability and mortality. Cutaneous diseases complicated by rhabdomyolysis are exceedingly rare in clinical practice, and cases presenting initially with subxiphoid pain are even more seldom reported. Therefore, clinicians should strive to enhance their understanding of this condition, closely monitor patients’ clinical manifestations, and ensure repeated serial assessments of relevant laboratory tests to facilitate early diagnosis and timely intervention.

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