WBR1031
| 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 49 year old man presents to his primary care physician with complaints of generalized muscle weakness and pain present all throughout the day for the past three days. It started as a vague neck pain before progressing to generalized muscle weakness. He also complains of drooping of his upper eyelids and inability to open his car doors because of hand weakness. Over-the-counter acetaminophen has not been helpful. He denies any history of fever, difficulty in breathing or swallowing and facial muscle weakness. He has a past medical history of gastroesophageal reflux disease and plantar fasciitis that was diagnosed before 1 week for which he is currently taking methylprednisolone. He has a history of smoking 1 pack of cigarette per day for the past 25 years and denies taking alcohol. On examination, his vital signs are blood pressure of 130/85 mm Hg, pulse rate of 80 beats/min, respiratory rate of 15 breaths/min and temperature of 37.2 °C. Bilateral ptosis is noticed and there is pain on palpation of both the upper and lower extremity. Muscle strength is 2 in both the upper and lower extremities. Handgrip is weak, and he has difficulty standing up from sitting position. Sensations are bilaterally normal and symmetrical. Normal deep tendon reflexes are noted. His complete blood count and basic metabolic profile are normal. His other lab tests revealed the following ESR : 10 mm/hr |
| Answer A | AnswerA::Polymyositis |
| Answer A Explanation | AnswerAExp::'''Incorrect'''- |
| Answer B | AnswerB::Dermatomyositis |
| Answer B Explanation | AnswerBExp::'''Incorrect'''- |
| Answer C | AnswerC::Neuromuscular junction disease |
| Answer C Explanation | AnswerCExp::'''Incorrect'''- |
| Answer D | AnswerD::Drug induced myopathy |
| Answer D Explanation | AnswerDExp::'''Correct'''- |
| Answer E | AnswerE::Polymyalgia rheumatic |
| Answer E Explanation | AnswerEExp::'''Incorrect'''- |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::The patient has developed complaints one week after beginning methylprednisolone. 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. Acute presentations are less frequent and usually occur after a week after the onset of treatment. They usually present as generalized muscle weakness rather than proximal muscle weakness. Myalgias and muscle tenderness do not occur. Most patients have high levels of serum creatine kinase, as well as associated myoglobinuria. Muscle biopsy show focal as well as diffuse necrosis of all types of fiber and some times EMG findings may be abnormal. 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:
Acute steroid induced myopathy should be considered in patients who begin to have generalized muscle weakness, elevated serum creatinine kinase levels and myoglobinuria around 1 week after the start of steroid treatment. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Drug induced myopathy, WBRKeyword::Steroid induced mypoathy |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |