Dr Ira Shah
M.D, DNB, DCH(Gold Medalist), FCPS

12 years old Female child presented with difficulty in eating and right axillary swelling & discharge since 3days. She had a violaceous rash over the face and the arms. There was a discharging ulcer in the right axilla, multiple soft tissue nodules over the elbow and knee (X Rays of the elbow and knee was suggestive of soft tissue calcifications). She had multiple joint contractures. (Fig 1)

4 years ago, she had presented with facial rash and proximal muscle weakness. She was investigated and her S. CPK was 13256 mg%( increased), ANA titres were positive (1:40), S. LDH was 3454 mg%(increased). MRI of the thigh showed increased signals involving entire pelvis and thigh muscles suggestive of myositis. Muscle biopsy done showed perifascicular atrophy with blocked small vessels. On the basis of the above clinical presentation and investigations she was diagnosed as Juvenile Dermatomyositis. She was treated with oral prednisolone, calcium supplements and physiotherapy and she went into remission. She relapsed again after 3 years with soft tissue calcifications, contractures and muscle weakness. She was treated with Inj methotrexate 12.5mg SC once a week, IVIG and oral prednisolone. She again went into remission with the same.

This time the child was diagnosed as severe JDMS with calcinosis & GI involvement. Her S. CPK this time was 914 mg%, S. LDH was 1572 mg%. Her absolute lymphocyte count was 2440 /cumm. An esophageogram showed regurgitation of barium from cervical esophagus with normal esophageal motility. She was treated with Inj methotrexate, oral prednisolone, IVIG, Cyclosporine and RT feeds. Patient continued to have dysphagia and on D24 of presentation developed severe and fatal hematemesis (PT/PTTK, platelet counts were normal) due to GI vasculopathy and expired due to the same.

JDMS is a chronic inflammatory muscle disease. It is associated with systemic vasculitis. It is characterized by dermal features & myositis leading to progressive proximal muscle weakness.

Diagnostic Criteria: In addition to characteristic rash, 3 of the following 4 should be present for diagnosis:

1. Symmetrical proximal muscle weakness


2. Elevated muscle derived enzymes (CPK, aldolase, LDH, SGOT)


3. Characteristic muscle histopathology


4. Electromyographic changes: inflammatory myopathy

Etiology :

Hypothesis - Triggered by infectious process in a genetically susceptible host. (Enterovirus, Coxsackie B, Group A Beta hemolytic streptococci)

Predisposing factors:

1. Exposure to sun


2. HLA antigen - DQAI*0501.

1. Age- Bimodal peak is seen at 5-9 years and 10-14 years


2. Sex –M:F= 1:2


3. Onset is insidious with fatigue, low grade fever and intermittent rash. Later the patient may develop arthralgia and proximal muscle weakness.

Cutaneous Manifestations

1. Characteristic erythematous rash over the eyelids (may cross bridge of nose and include nasolabial folds). Rash has violaceous or heliotropic hue.



2. Skin over the knuckles may become hypertrophic & red in acute phase (Gottron papules) & then form atrophic bands.



3. Periorbital edema & telangectasia

Proximal muscle weakness

Median age is 2 months after the onset of rash. Positive Gowers sign may be present. Patient may develop neck flexor weakness (inability to raise the head from bed).

Calcinosis:

1. Seen in 30% of JDMS.
   
   
2. It is seen in severe & long standing cases.
   
   
3. Calcinosis appears at trauma sites (Knees, elbows, buttocks).
   
   
4. Children treated early and aggressively do not develop soft tissue calcifications. These calcifications may also resolve spontaneously draining as white, cheesy exudate leaving dry, pitted scars. In persistant disease, calcifications become sheath like impairing movement & breaking the skin leading to infection.
   
   

Gastrointestinal Involvement

GI dysfunction is due to vasculopathy and impairment of muscle function. There is decreased esophageal motility. There may be a nasal, high pitched speech. The vasculopathy leads to ulceration, perforation and hemorrhage. It can also lead to malabsorption.

Cardiopulmonary Involvement: It may be seen in the form of

Bundle branch blocks

Pulmonary fibrosis

Ophthalmic Involvement: It may be seen in the form of retinal exudates.

Other manifestations:

CNS- seizures, Depression
Renal impairment due to myositis & increased breakdown.

1. Increased muscle enzymes (CPK, aldolase, LDH, SGOT)


2. Positive ANA with speckled pattern (60%)


3. Antibodies to Pm/Scl


4. Lymphopenia & increased CD19+ B cells


5. MR1- to locate active site of disease.


6. Muscle biopsy- An MRI guided biopsy should be done to localize the muscle with maximum disease activity. The muscle biopsy shows perifascicular atrophy, predominance of round cells and occlusion of small vessels.


7. EMG – shows inflammatory myopathy (Early full recruitment with reduced motor unit activity).

Treatment criteria consists of normalization of clinical and laboratory findings.

1. If there are only cutaneous findings - Chloroquine(2mg/kg/d) and oral prednisolone (0.5mg/kg/d) is useful.
   
2. In cases of mild muscle damage –Oral prednisolone (1-2mg/kg/d) is useful.
   
3. In severe disease - IV methyl prednisolone (30mg/kg/d for 3 days) with gradual decrease in dose is desirable. Other drgs that are found useful in severe diseases are Cyclophosphamide, IVIG, cyclosporine, Methotrexate (Subcutaneously in view of poor absorption orally due to GI vasculopathy).
   
4. The main stay of the treatment is physiotherapy. Adjuvant Calcium and Vitamin D supplementation is necessary.
   
5. Sun screen lotions may be tried if there is evidence on exacerbation with sun exposure.
   
6. Dietary care, TPN may be required in cases of malabsorption.
   
7. Newer therapies for calcinosis being tried are Probenecid, Diltiazem, Alendronate.
   
   

Last updated on 10-11-2002