Dr.Jerin.K.John, Dr.Suma Balan, Dr.C.Jayakumar
AIMS KOCHI
A 3-year-old boy presented with fever and skin rashes 10 months back which was followed weakness with difficulty in getting up from sitting position and joint pain. Joint pain got resolved but weakness and skin rashes persisted. He was on treatment from alternative system of medicine without relief. Examination revealed violaceous papules on knuckles (Gottrons papules), erythematious rashes more on sun exposed areas including face and generalised dryness of face. Other systems were clinically normal.
Differential diagnosis
1. Juvenile Idiopathic Arthritis (JIA)
2. Systemic Lupus Erythematosus (SLE)
3. Systemic Sclerosis (Scleroderma
4.Juvenile dermatology myositis
5.Infectious Causes (e.g., viral myositis)
6.Overlap Syndromes (e.g., mixed connective tissue disease)
7.Metabolic Myopathies (e.g., mitochondrial myopathies)
8.Malignancies (e.g., lymphoma)
9.Other Autoimmune Myopathies (e.g., polymyositis)
10.Drug-Induced Myositis
11.Other Rheumatic Conditions (e.g., vasculitis)
Labs .Neutrophilic leukocytosis TC-18 Ku/ml with elevated CRP-12 mg/L
ESR-69 mm/hr
Compliment levels normal
SGOT 129 IU/ L and normal
Electrolyte level normal
His myositis panel showed strong positivity for MDA5.(Myositis panel include myositis specific antibodies and myositis associated antibodies )
In this case MDA 5 was positive which is myositis specific antibody which is associated with rapidly progressive interstitial lung disease and mild muscle disease with low CK levels
MRI thigh showed abnormal assymetrical hyperintense signal in anterior, posterior, medial compartment of right thigh(involvement of rectus femoris, semitendinosis, semimembranosis, abductor Magnus and left gluteus maximum muscle )suggestive of myosotis.
His chest X-ray showed B/L non homogenous opacities in all zones,
CT chest which showed possibility of organising pneumonia.
He underwent a BAL , bronchoscophy and ECHO which was normal.
He was started on methylpred and Iv Ceftriaxone.
In view of visceral involvement and active nature of disease he was started on
inj Cyclophosphomide and IVIG and was discharged Co -trimoxazole prophylaxis.
Picture 1 Pneumonia
picture 2 Gottrons papules.
Juvenile Dermatomyositis
It is a systemic vasculopathy with involvement of skin and focal area of myositis resulting in proximal muscle weakness with an incidence of 3-4 per million children per year. The etiology of the condition is unclear yet. There may be involvement of joints, kidney, brain, lung and intestine. The prognosis has significantly improved over recent years with the emergence of new therapeutic options. Early treatment and close monitoring may lead to better control of the disease. Most recover in 6 months to 2 years. Recurrence is rare. Those who don’t respond to steroids may be treated with azothioprine, methotrexate or cyclosporine as adjuvant agents.
