- Patient presentation
- Differential Diagnosis
- Final outcome
- Evaluation - Questions & answers
A 7 year old female presents with a three week history of painful elbows, wrists and hands, generalised weakness and difficulty walking.
This case study was kindly provided by Dr Bhadrish J Mistry, Paediatrician, Department of Paediatrics, Chris Hani Baragwanath Hospital and the University of Witwatersrand.
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- Painful elbows, wrists and hands for 3/52
- Sore throat
- No early morning stiffness, but a generalised weakness and family reports that she is “walking funny”
- First episode of any illness, otherwise previously well
- No history of rash, fever, headache or abdominal pain
- No chronic medication or traditional medicines, no medication taken for these symptoms
- No known allergies
Past Medical History:
- No previous hospital admissions
- No major illness
- No history of TB
- Patient is an orphan. Father died in a work related accident 4 years ago, with some lower limb weakness reported at the time (details not available). Mother died of a brain tumor 2 years ago
- Child has still not come to terms with loss of her parents, often quiet and withdrawn
- Grandmother is primary care giver
- Lives in house with all amenities
- Currently at school in grade 2
- Oligoarthritis- evolving juvenile arthritis
- Myositis- idiopathic or infective
- Dermatomysositis- no rash, no calcinosis on history
- Systemic Lupus Erythematosus
- Neuromuscular disease
- Muscular dystrophy
- Pleasant co-operative child
- Growing well, 25th centile for height and weight (23 kg and height 120 cm)
- Vital signs are normal
- Mild pallor observed in conjunctiva and palms
- Oedema of the face with periorbital puffiness and a swollen upper lip
- Bilateral oedema of the elbows, knees and shins
- No clubbing present
- Shotty generalised lymphadenopathy found in anterior and posterior cervical nodes, axillary nodes and inguinal nodes.
- Heliotrope rash on left eyelid
- Capillary changes in nail bed, no other skin lesions
- No chest deformity, trachea central and good bilateral air entry.
- No precordial bulge, no heaves or thrills, apex beat in 6th intercostal space mid axillary line. Normal heart sounds, no murmurs.
- Soft, non-tender, no ascites
Central nervous system
- Alert and awake higher function is appropriate
- No muscle wasting
- Decreased tone, cannot sit up in bed unassisted
- Decreased reflexes bilaterally upper and lower limbs
- Decreased power, bilaterally, upper and lower limbs
- No clonus
- Generalised weakness, more proximal than distal
- Waddling gait, leans to right when walking
- Gower’s sign present
|WCC||6.19||(4.5 – 13.5)|
|HB||10.3||(11.5 – 13.5)|
|MCV||86.1||(75 – 87)|
|HCT||0.31||(0.34 – 0.40)|
|PLTS||380||(150 – 550)|
|Neutrophils||0.81200000000000006||(absolute 5.03) N|
|Lymphocytes||0.11899999999999999||(absolute 0.73) L|
|Monocytes||6.3E-2||(absolute 0.39) N|
|ASOT||452||(0 – 250)|
|Free T4||13.8||(11 – 18.8)|
|TSH||4.9400000000000004||(0.48 – 4.67)|
|Vit B12||301||(145 -637)|
|Red cell folate||1617||(924 – 3337)|
- Abdominal ultra sound – normal
- ECG- normal
- Chest X-ray: normal
- PPD- negative
Childhood myositis assessment scale (CMAS) score = 14/52, indicates low muscle strength and low endurance.
- Muscle biopsy – features are those of an inflammatory myopathy.
- EMG- of biceps brachii , shows axonopathy
- MRI of thighs- confirmed myositis
Patient was initially treated with polygam 2g/kg twice a week and oral steroids (meticorten) 2mg/kg daily. Physiotherapy and Occupational therapy were prescribed daily and she was assessed by a dietician for nutritional support.
For the first three weeks of treatment the patient reported feeling better, with joint swelling and pain resolving. She still complained of proximal muscle weakness but this had also improved since admission.
After three weeks the patient started feeling unwell again with proximal weakness worsening and unable to move from a lying to sitting position without assistance. She also started drooling excessively and was reluctant to eat.
A Barium swallow was ordered but was normal. Treatment with polygam and oral steroids was continued. Muscle biopsy was ordered with showed an inflammatory myopathy.
Patient continues to deteriorate. Developing bulbar speech and inability to swallow.
Patient was intubated and admitted to medical ICU for intermittent positive pressure ventilation (IPPV). She was continued on treatment with polygam, also given methyl prednisone IV and 15 mg of Methotrexate sub cutaneously.
Patient continued to deteriorate. ESR, CRP and CK levels remained elevated. She also developed pseudomembranous colitis (treated with metronidazole) and MRSA sepsis (treated with meropenem and Vancomycin). Child had a cardiac arrest and was successfully resuscitated.
Tracheostomy was placed and Rituximab therapy, a monoclonal antibody was started.
Patient started to respond to treatment showing steady improvement, able to sit up unassisted and move arms, head and feet.
Patient was released from ICU to high care. Nerve conduction studies were done which showed a secondary axonopathy. Treatment and therapy were continued
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For two weeks post ICU the patient continued to improve steadily. She then developed a nosocomial pneumonia for which she was successfully treated and thereafter continued to improve.
At the start of the third week she started gasping, resuscitation attempts failed and the patient died 11 weeks post admission.
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Evaluation – Questions & answers
What is the diagnosis?
Diagnosis is also based on a set of the following criteria proposed by Bohan and Peter; where the presence of three of the findings listed indicates probable myositis; four indicates myositis and diagnosis of juvenile dermatomyositis requires the skin changes mentioned in point 5 (see below).
- Proximal muscle weakness (upper or lower extremity and trunk); typically symmetrical
- Elevated serum creatine kinase (CK) or aldolase levels
- Muscle biopsy showing inflammation, damage or other characteristic changes in muscle tissue
- Myopathic changes on electromyogram (EMG)
- Skin rash
– Heliotrope rash (reddish-purple erythema on the upper eyelids, often with oedema)
– Gottron’s sign (reddish-purple nodules on the extensor surface of finger, elbow or other joints)
What is believed to trigger the autoimmune response in dermatomyositis?
Where is the autoimmune reaction in dermatomyositis first triggered?
What is a normal antigen specific B lymphocyte activation?
What is the normal antibody mediated destruction process of a pathogen?
What antibody process occurs in dermatomyositis?
What are the processes which are involved in destroying the capillary endothelial cells in dermatomyositis?
In dermatomyositis what are the effects of destruction of the muscle cell capillaries
How is autoreactive B lymphocyte activation altered in dermatomyositis?
What are the aims of therapy and what therapy can be initiated?
Rituximab a monoclonal antibody therapy has been shown to have five possible mechanisms of action against dermatomyositis
Classical complement activation
C3b opsonisation and phagocytosis
IgG opsonisation and phagocytosis
Antibody-dependent cell cytotoxicity by natural killer cells
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