8. Polymyositis
A persistent inflammatory muscle disease that
causes weakness of the skeletal muscles, which
control movement.
Medically, polymyositis is classified as a chronic
inflammatory myopathy — one of only three such
diseases.
10. Polymyositis
signs and symptoms usually develop gradually,
over weeks or months.
Remissions - rare
Remissions: periods during which symptoms spontaneously
disappear
11. Signs and symptoms
appear gradually,
Progressive muscle weakness
Difficulty swallowing (dysphagia)
Difficulty speaking
Mild joint or muscle tenderness
Fatigue
Shortness of breath
12. Signs and symptoms
affects the muscles closest to the trunk,
particularly hips, thighs, shoulders, upper arms
and neck.
weakness is symmetrical
worsens over time.
As muscle weakness progresses,
difficult to climb stairs, rise from a seated position, lift
objects or reach overhead.
13. Complications
Dysphagia
Which in turn may cause weight loss and malnutrition.
Aspiration pneumonia
Shortness of breath or respiratory failure.
Calcinosis
Calcium deposits in muscles, skin and connective
tissues
14. Associated conditions
Polymyositis is often associated with other
conditions that may cause further complications
of their own, or in combination with polymyositis
symptoms. Associated conditions include:
Raynaud's phenomenon.
Other connective tissue diseases.
Cardiovascular disease.
Lung disease.
17. DIAGNOSTIC CRITERIA
4. MUSCLE BIOPSY:
biopsy a clinically weak muscle, contralateral to an
abnormal muscle ( by EDT), MRI directed.
a. Perivascular and endomysial inflammation
CD8+ T cells in PM,
CD8+, CD4+ T and B cells in DM
b. b. Muscle fiber necrosis and regeneration
19. Myositis-specific
AUTOANTIBODIES
ANTI Jo-1 part of ANTI SYNTHETASE Ab’s
Antibodies to the antigen- Aminoacyl-tRNA
synthetase, in 20-50% of PM>>DM
ANTI SRP = anti signal recognition particle
In 5% of PM
ANTI Mi-2 in 10% of DM.
22. Macrophage or
Activated T Cell
Soluble TNFa
Target Cell
TNFa
Receptor
Signal Induction
Synthesis and Function of
TNFa
Transmembrane
TNFa
Receptor-Bound TNFa
24. Humira- The first fully human
antiTNFa
Chimeric
Antibody
70% Human
Humanized
Antibody
95% Human
Fully Human
Antibody
100% Human
Mouse
Human
Chimeric Humanized Fully Human
24
25. Treatment
corticosteroid
When muscle strength improves, usually in 4 to 6
weeks, the medication is slowly tapered off.
Maintenance therapy with prednisone may be
continued indefinitely.
DMARDs - If unresponsive to corticosteroids
methotrexate and azathioprine,
26. Treatment
Intravenous gamma globulin
IVIG
is a purified blood product that contains healthy
antibodies from thousands of blood donors.
The healthy antibodies in IVIG can block the
damaging antibodies that attack muscle in
polymyositis.
Repeat infusions q 6-8 weeks
31. Dermatomyositis
a muscle disease characterized by inflammation
and a skin rash. It is a type of inflammatory
myopathy.
5 - 15 and adults age 40 - 60.
Women
Polymyositis is a similar condition, but the
symptoms occur without a skin rash.
Maria Carmela L. Domocmat, RN, MSN
33. Symptoms
The muscle weakness may appear suddenly or develop
slowly over weeks or months. may have difficulty raising
arms over head, rising from a sitting position, and
climbing stairs.
The rash may appear over the face, knuckles, neck,
shoulders, upper chest, and back.
Maria Carmela L. Domocmat, RN, MSN
35. purple (violaceous) plaques
The appearance of purple
(violaceous) plaques on
the knees may be
associated with
dermatomyositis.
Maria Carmela L. Domocmat, RN, MSN
37. Heliotrope eyelids
eyelids develop a brown
(violaceous - rather than
red) color.
Heliotrope eyelids and
Gottron's papules on the
knuckles are
characteristic findings in
dermatomyositis.
Maria Carmela L. Domocmat, RN, MSN
40. Dx Exams
CPK & aldolase
ECG
Electromyography
Magnetic resonance imaging (MRI)
Muscle biopsy
Maria Carmela L. Domocmat, RN, MSN
41. Treatment
Corticosteroids
Immunosuppressants
When muscle strength gets better – taper off
corticos
However, most people take prednisone
indefinitely.
If the condition is associated with a tumor, the
muscle weakness and rash may improve when
the tumor is removed.
Maria Carmela L. Domocmat, RN, MSN
42. Outlook (Prognosis)
Some recover and have symptoms completely
disappear - especially in children.
In adults, death may result from severe and
prolonged muscle weakness,
malnutrition, pneumonia, or lung failure. The
major causes of death are cancer (malignancy)
and lung disease.
Maria Carmela L. Domocmat, RN, MSN
43. Possible Complications
Acute renal failure
Cancer (malignancy)
Inflammation of the heart
Joint pain
Lung disease
Maria Carmela L. Domocmat, RN, MSN
45. ANTI-SYNTHETASE SYNDROME
associated with anti-Jo1 antibodies with acute onset of PM>> DM
disease.
Associated with ILD -40-60%, deforming and non-erosive arthritis,
Mechanic’s hands and Raynaud’s phenomenon