What is the prognosis for Polymyositis?

So I needed to get real and face what might be going to happen if the immunosuppressants do not work to stop the progression of the disease. Here is what I found:
The prognosis for polymyositis varies. Most people respond fairly well to therapy, but some have a more severe disease that does not respond adequately to therapies and are left with significant disability. In rare cases individuals with severe and progressive muscle weakness will develop respiratory failure or pneumonia. Difficulty swallowing may cause weight loss and malnutrition. National Institute of Neurological Disorders and Stroke

The progression of PM and DM varies considerably from person to person. Immunosuppressants can improve strength, although not all patients respond, and relapses may occur. PM and DM can lead to increasing weakness and disability, although the life span usually is not significantly affected. About half of the patients recover and can discontinue treatment within five years of the onset of their symptoms. About 20% still have active disease requiring ongoing treatment after five years, and about 30% have inactive disease but some remaining muscle weakness. Gale Encyclopedia of Medicine

Although polymyositis and dermatomyositis are regarded as treatable disorders, prognosis is not well known, as in the literature long‐term outcome and prognostic factors vary widely.  U.S. National Library of Medicine

Polymyositis is what?

Just so we are clear - I have a Neuromuscular Disorder. It is an Acquired Inflammatory Myopathy, as is Dermatomyositis (DM) and Inclusion Body Myositis (IBM). It is called Polymyositis. These diseases are also called idiopathic inflammatory myopathies and are grouped together due to muscle inflammation. Polymyositis,  Dermatomyositis and Inclusion Body Myositis result in muscle degeneration and muscle weakness and are therefore also called muscle disorders.

In polymyositis the inflammatory cells of the immune system directly attack muscle fiber s.

RESOURCES: Institute for Neurological Discoveries: Neuromuscular and Movement Disorders Division: KU Medical Center: University of Kansas.

You may also be intereted in:

• Occurrence of polymyositis
• Why Myositis is hard to diagnose

How rare is Myositis?

Myositis is a rare disease diagnosed in just 1 in 100,000 people a year.*  Some people think the number should be higher as many cases may go unidentified. It is often mistaken for the symptoms of aging even by sufferers or fibromyalgia or depression.  Many patient see seven or more doctors before getting the correct diagnosis of Myositis. This is what happened to me.
                                  

The three main types of myositis, or inflammatory myopathy, are polymyositis, dermatomyositis, and inclusion body myositis. All 3 diseases involve chronic muscle inflammation, accompanied by muscle weakness.  

• There are 2 separate ages of onset: 10 - 15 years and 45 - 60 years.
• Female to male ratio is 2 :1 except in inclusion-body myositis (IBM) where it is reversed.
• Prevalence of the disease is the highest in the Japanese.

* 2013 American College of Rheumatology

The maze of diagnosis

Today I visited the Muscular Dystrophy Australia website as Myositis falls under this umbrella. I use to go on this site years ago and chat, to Ryan a young man with MD, as I thought that my condition was going to be in this general area - muscles that don't work.

"polymyositis is hard to diagnose and may be mistaken for muscular dystrophy." MDA

See here  for more explanation of all the diseases that come within Muscular Dystophy.

Why Myositis is hard to diagnose

According to the Sydney Medical School - The University of Sydney - all of these conditions have proximal muscle weakness which may be why it took so long to diagnose me with polymyositis:

*Denervating conditions: spinal muscular atrophies, amyotrophic lateral sclerosis
*Neuromuscular junction disorder: Eaton-Lambert syndrome, myasthenia gravis
*The genetic muscular dystophies: Duchenne's fascioscapulohumeral, limb girdle, Becker's, Emery-Dreifuss type, distal, ocular
*Myotonic diseases: dystrophia myotonica, myotonia congenita
*Congenital myopathies: nemaline, mitoctondrial, centronuclear, central core
*Glycogen storage diseases: adult onset acid maltase deficiency, McArdle's disease
*Lipid storage myopathies: carnitine deficiency, carnitine palmityltransferase deficiency
*The periodic paralyses
*Myositis ossificans: generalized and local
*Endocrine myopathies: hypothyroidism, hyperthyroidism, acromegaly, Cushing's disease, Addison's disease, hyperparathyroidism, hypoparathyroidism, vitamin D deficiency myopathy, hypokalemia, hypocalcemia
*Metabolic myopathies: uremia, hepatic failure
Toxic myopathies: acute and chronic alcoholism, drugs including penicillamine, clofibrate, chloroquine, emetine
*Nutritional myopathies: vitamin E deficiency, malabsorption
*Carcinomatous neuromyopathy: carcinomatous cachexia
*Acute rhabdomyolysis'
*Proximal neuropathies: Guillain-Barre syndrome, acute intermittent porphyria,chronic autoimmune polyneuropathy
*Microembolization by atheroma or carcinoma
*Polymyalgia rheumatica
*Other collagen vascular diseases: rheumatoid arthritis, sclerocerma, systemic lupus erythematosus, polyarteritis nodosa
*Infections: acute viral, including influenza, mononucleosis, rickettsia, coxsackie virus, rubella and rubella vaccination, acute bacterial including typhoid
*Parasites: including toxoplasma, trichinisla, schistosoma, cysticerci, sarcosporidia
*Septic myositis: including staphylococcus, streptococcus, clostridium welchft, and leprosy
Myasthenia gravis is the prototypical disorder of the neuromuscular junction, in which weakness often affects the extraocular and bulbar muscles and becomes worse with repetitive contraction. A similar pattern of activity-increased weakness is found in Eaton-Lambert syndrome. Both of these diseases can cause proximal muscle weakness, but can be separated from polymyositis/dermatomyositis by their characteristic electromyographic patterns as well as absence of serum muscle enzyme elevation.
Glycogen storage diseases result from enzyme deficiencies involving the glycolytic pathway. McArdle's disease, or myophosphorylase deficiency, is caused by failure to degrade glycogen for energy under anaerobic conditions. Disorders of muscle lipid metabolism may mimic polymyositis. Carnitine deficiency results in inability to transport long-chain fatty acids into mitochondria for oxidation, leading to lipid accumulation in muscle fibers and a chronic proximal myopathy.
Other causes of proximal myopathy include vitamin D deficiency, adrenal insufficiency, hypophosphatemia, hyperthyroidism, carcinomatous neuromyopathy and exposures to various toxic substances. A variety of drugs are capable of producing inflammatory or noninflammatory myopathy include: chloroquine, cimetidine, clofibrate, colchicine, corticosteroids, cyclosporin. Ethanol, heroine, ipecac, levadopa, lovastatin, penicillamine,phenytoin, nicotinic acid, vincristine, zidovudine."
Read full PDF here

There are many types of myositis

Types of myositis include:

• myositis ossificans
• fibromyositis
• idiopathic inflammatory myopathies
• dermatomyositis: A rash usually accompanies or precedes the muscle weakness
• juvenile dermatomyositis
• polymyositis : chronic muscle inflammation accompanied by muscle weakness affecting proximal
• inclusion body myositis: chronic, progressive muscle inflammation accompanied by muscle weakness affecting proximal and distal muscles
• pyomyositis

Do not put things off when it comes to your health

 I had put off a muscle biopsy for a year because I was scared and because I needed to have a transfusion before I had it. It was fear of the unknown, never having had either procedure before. This was the muscle biopsy that diagnosed my Myositis after all these years. This is how I felt when I was finally diagnosed from a muscle biopsy.