2022 Volume 13 Issue 1 Pages 43-47
There are various causes of hypercreatine kinasemia (hyperCKemia) including rheumatic diseases and hypothyroidism. Here, we reported the case of mixed connective tissue disease (MCTD) complicated with Hashimoto’s disease (HD), who developed hyperCKemia with each exacerbations of MCTD and HD. A 9-year-old girl with recurrent Raynaud’s phenomenon since the age of 7 years, developed fever, abdominal pain, neck pain, torticollis with cervical lymphadenopathy, hyperCKemia, and hypothyroidism. She was diagnosed with MCTD complicated with HD, and achieved remission with methylprednisolone pulse therapy. Thereafter, mycophenolate mofetil (MMF) was added, and remission was maintained. Levothyroxine (LT) was also started and was stopped after 4 months as thyroid function normalized. At the age of 10 years, the patient presented with abdominal pain, vomiting, and hyperCKemia, which was suspected to be an exacerbation of MCTD. However, at the same time, the exacerbation of hypothyroidism was also seen. LT was restarted and her symptoms were improved soon. At the age of 12, she developed neck pain, torticollis, and hyperCKemia again. Thyroid function was preserved with LT. The exacerbation of MCTD was suspected, and her symptoms and hyperCKemia improved after the doses of PSL increased. MCTD is frequently complicated with HD. Hypothyroid myopathy should be considered as a cause of hyperCKemia in patients with MCTD.
