Allergies or Something Else?
In a recent Case in Point™ case of the month, radiologists uncover an uncommon diagnosis for a young patient in need of answers.
The four-year-old girl arrived at Greenville Health System with severely swollen eyes, skin rash, and leg muscle weakness. The patient had been seen a week earlier at an outside emergency room and was treated for allergies but had been unresponsive to treatment.
Before the patient left their care, Tristan R. Lawson, MD, then a third-year medical student at the University of South Carolina School of Medicine in Greenville, and Jeffrey R. Wienke, MD, radiologist and director of musculoskeletal imaging at Greenville Health System, would make an unexpected diagnosis. The physicians eventually submitted the case to Case in Point™ (CiP), where 12,800 daily subscribers access unique and interesting diagnoses while earning CME. It won case of the month for June 2017.
With MRIs and additional tests, Lawson and Wienke were able to apply the correct and rare diagnosis of juvenile dermatomyositis (JDM). If not properly diagnosed and treated, JDM can manifest as a chronic condition, flaring up at intervals throughout the child’s life and into adulthood.
JDM is an inflammatory disease of the muscle, skin, and blood vessels that affects approximately three out of 1 million children each year. The cause is unknown. JDM appears with diffuse hyperintense signal on T2-weighted MR imaging and dystrophic calcification on plain films. A patient can present with varying symptoms, ranging from mild muscle weakness to difficulty swallowing. Patients also generally develop a skin rash that ranges from mild redness to a more severe ulcer formation. JDM is diagnosed with MRI, muscle biopsy, and blood tests for elevated creatine kinase levels and certain antibodies that are associated with JDM.
Immunodepressive therapy including cortiscosteroids, especially glucocorticoids (which limit the production of antibodies, reduce skin and muscle inflammation, and improve muscle strength and function) are commonly prescribed in very high doses until signs and symptoms improve.
Lawson was drawn to the uncommon pathology and differential diagnoses in this case, including things like parasitic infection and autoimmune disease. “Hopefully this case provides readers with a useful synopsis of the clinical presentation of JDM,” he says, “as well as key imaging and pathological features, potential differential diagnoses, and treatment.” He notes that JDM can be misdiagnosed as an allergic reaction, as it was during a previous visit for this patient. “Case presentations are a great way to learn radiology as a student,” says Lawson. “Seeing a real-life example of a rare pathology makes the information stick with you.” Wienke adds about working on this case, “In the landscape of subspecialization, this case illustrates the importance of a solid understanding of general radiology.”
Lawson learned a great deal from working on this case, through the process of reviewing images and recognizing the limitations and advantages of different imaging modalities and MRI sequences. “I also was unaware that JDM is thought to be a combination of genetic predispositions and environmental triggers,” he says. “CiP is a great format for learning and sharing interesting cases. The process helps reinforce the information for both the author and the reader. Plus the cases are fun to work through.”
As a medical student, Lawson used CiP often to test his knowledge base. His favorite cases were “the ones that presented several different imaging modalities so I could see the pathology through different lenses.” He also appreciates the cases that discuss clinical presentation and treatment. He is still an avid CiP user today, always looking for exposure to new pathologies and new imaging findings. “As a new radiology learner, I often learn the most about the imaging modalities themselves and their limitations and advantages,”Lawson says. “Through analyzing and writing about this case, I learned about the different MRI sequences used in musculoskeletal radiology, including T1, T2, and STIR. As a student, this was a difficult concept and one that I definitely appreciated learning more about.” He adds, “CiP has been a great learning opportunity and furthered my interest in radiology.” Due to the interest sparked by preparing this case and other factors, Lawson chose to pursue radiology as a specialty and is excited to begin formal training at Wake Forest Baptist Medical Center in Winston-Salem, N.C., later this year. “I’m ready to be a part of this fascinating profession.”
By Dara L. Fox, editorial assistant, ACR Bulletin