Dermatomyositis - Pictures, Symptoms, Treatment, Diagnosis, Causes
What is Dermatomyositis?
Dermatomyositis is a rare and systemic disorder characterized by inflammation of the skin and muscle resulting to muscle weakness and pain and development of rash. It is among the inflammatory myopathies that are related to polymyolitis although the latter does not involve the skin.
Dermatomyositis can occur in both adults and children with peak onset of age in adults between 40 to 60 years while the onset in children is between the ages of 5 to 10 years. This inflammatory disorder predominantly occurs in women than in men and without racial predilection.
The mortality of dermatomyositis is implicated on the involvement of cardiopulmonary and weakness of muscle. Malignancy is also another involvement in the disorder that can lead to death of patient. The prognosis for dermatomyositis is poor prior to the development and discovery of modern treatment and modern time found the disorder to be treatable although there is still the possibility for remission while it is still important for early detection and treatment of this type of inflammatory disorder. Development of contracture and complication of calcinosis is potential for children in severe form of dermatomyositis. The possibility of contracture however, is highly potential to patients who remained immobile during the course and progression of the inflammatory disorder.
Subtypes of Dermatomyositis have also been identified each with distinctive presentation.
Childhood Dermatomyositis affects children below the age of 18 years and is characterized by autoimmune inflammatory disorder of the muscle ad vasculopathy. The onset of the disorder often begins with general symptoms of fatigue, muscle weakness and fever and if the disorder is left untreated could lead to muscle wasting and immobility of the affected child.
Amyopathic Dermatomyositis is also called Dermatomyositis-sine-myositis. It is a Dermatomyositis marked by a skin rash characteristic of the disorder including muscle inflammation although without involvement of muscle weakness but debilitating fatigue is reported experienced by some patients.
Primary Idiopathic Dermatomyositis is a subtype that can occur at any age with manifestation of changes in the skin following muscle weakness including a diffuse erythema.
Dermatomyositis with cancer is an inflammatory disorder associated with malignancy. This is often a Dermatomyositis with poor prognosis and mortality is often from the malignancy.
Dermatomyositis is initially manifested through onset of skin rash followed by muscle weakness although there are cases where skin rash occurs simultaneously with muscle weakness or skin rash may precede muscle weakness as in the case of primary idiopathic dermatomyositis. The rash may be characterized by the following:
- With burning or itching sensation
- The rash is often bluish or purplish in color especially in the areas exposed to sunlight
- Rash predominantly affects the proximal muscle or the areas closest to the trunk while it may also develop in the cheeks, nose and shoulders
Changes in skin are the predominant manifestation of Dermatomyositis where the skin has reddish or purplish discoloration consisted of rash. The first sign of Dermatomyositis is the bluish-purplish color of patchy rash. The periorbital also develops a halo like rash which is called a heliotrope which is common in the upper eyelids although may also develop in the lower eyelid in rare occasion. The knuckles and areas in between the toes also develop a rash called Gottron’s sign. Calcinosis is also noticeable although this one is a complication of the inflammatory disorder.
Muscle weakness often precedes skin rash in most cases and rarely occurs before the onset of skin rash. The muscle weakness usually involves those closest to the trunk affecting both the left and right side of the body. The weakness in muscle is progressive and can be noted with the following signs:
- Inability or difficulty in standing up from a sitting position or lying down position
- Difficulty in walking and climbing up stairs
- Difficulty in lifting or raising up arms
Other general symptoms of Dermatomyositis include the following:
- Muscle and joint pain and tenderness
- Dysphagia or difficulty in swallowing
- Development of calcinosis which is common in child dermatomyositis.
- Onset of fever
- Loss of weight
- Ulcers and perforations of the gastrointestinal which is common in children with dermatomyositis.
The exact etiology of Dermatomyositis remains unclear and a compromised immune system is being implicated for the cause of the disorder where the immune system is triggered to produce an autoimmune antibodies that mistakenly attacks the own and healthy tissue of the body instead of the foreign substances in which the immune system is meant to ward off. Muscle degeneration in the disorder is due to affected small blood vessels that are being surrounded by the inflammatory cells during the course of the disorder. It is also believed that Dermatomyositis is being triggered during the process of the immune system in warding off the occurrence or development of cancer. Factors are also being considered for the onset of Dermatomyositis which some researchers have theorized to contribute in the development of the disorder and these factors include the following:
- Autoimmune disorders
- Genetic or hereditary predisposition
- Infection from bacteria and virus and other toxic agents that invade the body
- Malignancy or existing cancer especially in geriatric patient
- Chemical or drug abuse
Dermatomyositis is easily recognizable among other inflammatory disease due to the distinct rash characteristic of the disorder. The distinctive rash alone can diagnose the onset of the disorder although doctors still recommend and utilize other test to further diagnose and confirm Dermatomyositis and these include:
- Blood test to determine elevation of certain muscle enzymes
- Muscle biopsy to determine inflammation in the muscle
- Skin biopsy in isolating Dermatomyositis from other condition
No exact cure has been identified for the treatment of Dermatomyositis except for the improvement of the condition of the skin and improvement of muscle strength. Suppression of the immune system is the primary action in reducing muscle inflammation and controlling the production of antibodies. Corticosteroid is the choice for managing Dermatomyositis and prednisone is the most prescribed by doctors.
The recovery and duration of response to treatment is a factor in the length of disability of patient and the duration is different from one patient to another depending on the overall health, age, muscle involvement and type of Dermatomyositis including type associated with cancer and other connective tissue disorder. It is however, important for an early detection and prompt treatment of the disorder to prevent further serious complication and mortality if left untreated.