WBR1032
| Author | PageAuthor::Vendhan Ramanujam |
|---|---|
| Exam Type | ExamType::USMLE Step 3 |
| Main Category | MainCategory::Community Medical Health Center, MainCategory::Primary Care Office |
| Sub Category | SubCategory::Musculoskeletal/Rheumatology, SubCategory::Musculoskeletal/Rheumatology |
| Prompt | [[Prompt::A 74 year old woman with complains of weight loss, progressive malaise, jaw claudication and scalp tenderness for the past 1 month. She also complains of one episode of transient complete loss of vision in her right eye and partial loss of vision in her left eye. On examination, she has a right tender, nodular and non-pulsatile temporal artery. Her lab tests revealed an erythrocyte sedimentation rate of 74 mm/hour and C-reactive protein of 52 mg/liter. She is immediately started on intravenous methylprednisolone 250 mg BD and oral prednisolone 80 mg OD. A following temporal artery biopsy is consistent with arteritis. Her symptoms resolved and her inflammatory markers improved over the next 3 days. She is discharged on oral prednisolone. Three months later she presents to the office with complaints of weakness. She has difficulty in standing up from sitting position and in climbing the stairs. Her lab tests revealed erythrocyte sedimentation rate of 10 mm/hour, C-reactive protein of 3 mg/liter and creatinine phosphokinase of 24 U/L. What is the most likely cause for this patient’s complaints?]] |
| Answer A | AnswerA::Polymyalgia rheumatica |
| Answer A Explanation | [[AnswerAExp::Incorrect-Polymyalgia rheumatica usually presents with stiffness and pain in the shoulder and pelvic girdle. It can be associated with headache as in the case of giant cell arteritis and usually occurs in age group of above 50 years of age.]] |
| Answer B | AnswerB::Inflammatory myositis |
| Answer B Explanation | [[AnswerBExp::Incorrect-Inflammatory myositis presents with proximal muscle weakness and elevated serum creatinine kinase and ESR levels. It is confirmed by muscle biopsy.]] |
| Answer C | AnswerC::Drug induced myopathy |
| Answer C Explanation | [[AnswerCExp::Correct-Chronic steroid induced myopathy should be considered in patients who begin to have proximal muscle weakness and normal serum creatinine kinase levels without myoglobinuria that occurs within weeks to years following initiation of steroid treatment.]] |
| Answer D | AnswerD::Chronic fatigue syndrome |
| Answer D Explanation | [[AnswerDExp::Incorrect-Chronic fatigue syndrome might resemble fibromyalgia, but presents with fatigue for a period of over 6 months and without multiple trigger points of tenderness.]] |
| Answer E | AnswerE::Fibromyalgia |
| Answer E Explanation | [[AnswerEExp::Incorrect-Fibromyalgia presents as a widespread pain disorder with multiple trigger points of tenderness. It is also associated with fatigue, poor sleep and depression.]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The patient has developed proximal muscle weakness 3 months after beginning methylprednisolone treatment for temporal arteritis. Myopathy is a known side effect of glucocorticoid (corticosteroid) therapy since it has a direct catabolic effect on skeletal muscles by affecting the metabolic process that provides amino acids as a substrate for gluconeogenesis. Steroid induced myopathy may either be acute or chronic. Chronic presentations are the most frequent presentations and they usually occur within weeks to years following initiation of steroid treatment. Proximal muscle weakness is the most common presentation and myalgia can become a prominent presentation later. Patients typically have normal serum creatine kinase levels. Rhabdomyolysis and myoglobinuria are absent. Muscle biopsy shows preferential atrophy of type II fibers and inflammation is absent. The main treatment recommendation for steroid induced myopathy is to decrease the dose of steroid or to discontinue the corticosteroid use. Alternate day dosing may also be considered.
Educational Objective:
Chronic steroid induced myopathy should be considered in patients who begin to have proximal muscle weakness and normal serum creatinine kinase levels without myoglobinuria that occurs within weeks to years following initiation of steroid treatment. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Drug induced myopathy, WBRKeyword::Steroid induced myopathy |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |