This is a nearly 5-year old female with an 18 month 
history of difficulty walking.  She presents to the ED 
with her parents because of an acute episode (3-4 
hours) of lower extremity pain and associated with her 
legs "giving out".  Her parents deny any  history of 
trauma, fever or recent infections.  Mother reports that 
she has complained of pain many times before.  Usually 
the complaints are worse in the morning and at night.  
She cries when she tries to put shoes or socks on or 
cries when her legs are touched during episodes of 
pain.  She now walks with a limp and has a stiff left 
knee.  Mother has also noticed firm nodules along her 
hip and lower extremities for 12 months and a lifelong 
history of poor weight gain despite a good appetite.  
She was evaluated by a genetics consultant at which 
time blood was taken and radiographs were obtained.  
Her mother does not know the results of these tests.
     PMH:  She is the product of twin gestation via 
spontaneous vaginal delivery.  Birth weight 1.8 kg.  She 
remained hospitalized for 5 days because of jaundice 
and a urinary tract infection.  There are no other 
hospitalizations or surgeries.
     Her early development was normal.  She walked at 
about 11 months, but suffered a minor fall and refused 
to walk again until 18 months of age.  At about 30 
months of age, her parents noted complaints of pain in 
her lower extremities, refusal to walk, tenderness of 
thighs and ankles, inability to climb stairs, and difficulty 
getting up from bed.  She has never been able to run.  
Her language development has been good.
     Family history:  Her twin brother and other sibling 
are healthy.  Her father had corrective surgery of both 
lower extremities as a child, but the reason for this is 
not known.  Her mother had a kidney tumor as a child, 
but the type of tumor is not known.  There is a history of 
arthritis in paternal uncles.  Mother specifically denies 
any family history of sickle cell disease, lupus, 
rheumatoid arthritis or muscular diseases.
     Social History:  She attends preschool and is able to 
keep up intellectually, but not in physical activities.

     Exam: VS T37.6, P110, R28, BP 105/56, Ht. 91 cm 
(5th%ile for a 3 year old ), Wt. 11.8 kg (5th%ile for a 3 
year old), HC 48 cm ( 5th%ile for a 30 month old ).  
This is a 5 year old female child, appearing small for 
age, who is awake and alert with facial dysmorphism.  
She is thin and appears chronically ill.  Her head is 
atraumatic with hypoplastic midline facial features.  
PERRL, EOMI.  TM's normal.  Oral mucosa clear, pink 
and moist.  Neck supple with full range of motion.  
Heart regular without murmurs, rubs or gallops.  Lungs 
clear.  Abdomen soft, non-tender, rounded without 
distention.  No hepatosplenomegaly or masses.
     Extremities:  Bilateral upper and lower extremity 
muscle wasting.  There are hypopigmented flat papules 
overlying her interphalangeal joints.  There are 
non-tender, firm, irregularly shaped subcutaneous 
nodules palpated over both lower extremities.  There is 
decreased range of motion of her left knee.  Her other 
joints have normal range of motion.  Her skin is warm 
with brisk capillary refill.  There are irregularly shaped 
hyperpigmented macules along her lower extremities 
and abdomen with firm subcutaneous nodules scattered 
along her lateral lower extremities and hips.  There are 
no bruises.  No cranial nerve deficits are noted.  
Sensation is intact.  UE motor strength 5/5 bilaterally.  
LE strength 3/5 in the proximal muscles and 4/5 in the 
distal muscles.  Plantars are downgoing bilaterally.  
Cerebellar function is intact.  DTR 2+ bilaterally and 
symmetric.

Radiographs of her painful lower extremities are 
obtained.

View radiographs.


What do these radiographs show?
     A.  Generalized subcutaneous calcifications
     B.  Vascular calcifications
     C.  Myositis ossificans
     D.  Artifacts


     These radiographs demonstrate extensive soft 
tissue calcifications. The calcifications do not follow any 
particular vascular pattern and are not attached to 
bone.

What diagnosis is most likely?
     A.  Juvenile Rheumatoid Arthritis
     B.  Systemic Lupus Erythematosis
     C.  Rheumatic Fever
     D.  Congenital Myositis Ossificans
     E.  Juvenile Dermatomyositis

Discussion
     Juvenile Dermatomyositis (JDMS) is a rare 
rheumatoid disorder which typically involves 
inflammation of the skin and striated muscles.  The 
pathophysiology of JDMS includes muscle lesions with 
a mix of degeneration and regeneration of muscle 
fibers, various muscle fiber sizes and perivascular 
lymphocytic infiltrates.  There is also vasculitis of small 
arteries, venules, and capillaries of the skin, muscle and 
GI tract.  Although unsure of the etiology there is an 
association with Coxsackie B viral infection.  Patients 
with JDMS pass through 4 phases:  1) Prodrome with 
nonspecific aches and pains.  2) Progressive muscular 
weakness.  3) Persistent active disease.  4) Recovery 
with contractures and calcinosis.
     The onset is usually insidious during phase 1 with 
vague aches and pains of the limbs, edema of the 
hands and feet, low grade fever and sometimes a 
nonspecific rash.  Stage 2 includes a violaceous 
heliotropic rash along the eyelids, ruddy and atrophic 
lesions along the extensor surfaces of the knees, 
elbows and hands, and periungual erythema.  The skin 
findings may come before or after muscle weakness.
     The muscular complaints usually are tenderness 
and symmetrical weakness of the proximal muscles and 
anterior neck flexors while sparing the face.  The 
disease can involve palatopharyngeal muscles which 
lead to regurgitation, a nasal voice and aspiration.  
When respiratory muscles are involved, patients often 
have a weak cough and are at risk for aspiration  
pneumonia, which may lead to respiratory failure.  This 
stage is also associated with a risk of GI hemorrhage 
and perforation.
     The third stage has a variable course.  A small 
percentage of patients have severe vasculitis and 
progressive muscular weakness unresponsive to 
therapy.  Many have a limited course lasting 1-2 years.  
Others like our patient, have a chronic pattern with 
frequent exacerbations and remissions lasting 2-5 years 
with progressive muscular atrophy and soft tissue 
calcifications.  The recovery phase is characterized by 
muscle wasting, contractures, and pigmentary changes.

References
     Swischuk L, Johns S.  Bones and Soft Tissues 
(chapter 4).  In:  Differential Diagnosis Pediatric 
Radiology.   Baltimore, MD, Williams and Wilkins, 1995, 
p307.
     Schaller JG.  Dermatomyositis (chapter 153).  In:  
Nelson WE, Behrman RE, Kliegman RM, Arvin AM 
(eds).  Nelson Textbook of Pediatrics, 15th ed.  
Philadelphia, PA,  W.B. Saunders Company, 1996, 
pp682-683.