Samantha Ruth Prabhu, a renowned South Indian actress, is well known for her work in Telugu and Tamil films and does not need any more introduction. Alongside acting, she is also an entrepreneur, philosopher, and social media activist who frequently campaigned for women’s empowerment. She has a huge fan base all over India.
In an Instagram post last year, she revealed that she had been diagnosed with autoimmune myositis which instantly became a cause of concern for her fans. Despite this, she expressed her gratitude to her followers and reassured them that she is handling, the disease with courage. The actress has been sharing updates about her health now and then. From working on strength in the gym to taking injections, the actress is on a road to recovery from her myositis [1].
Autoimmune myositis is a condition in which the body's immune system attacks the muscles, causing weakness of the muscles. The weakness of the muscles results in difficulty in performing day-to-day activities. This disease gained widespread attention when it was linked to Indian film actress and model Samantha Ruth Prabhu [1].
Read on to learn more about autoimmune myositis.
As the name indicates it is a rare autoimmune condition that affects the skeletal muscle system. The body’s immune system attacks the muscle fibers which leads to their inflammation with cardinal signs of rubor (redness), tumor (swelling), calor (increased temperature), dolor (pain), and functio laesa (loss of function) [2]. The clinical features of this condition are as follows:
Autoimmune myositis is a condition that shows bimodal age distribution once at 5 to 15 years and the other at 45 to 60 years. Symptoms are almost similar in both age groups with muscle inflammation (myositis) developing suddenly in children. Features include weakness in the upper arms, hips, and thighs which is symmetrical on both sides, pain in the joints, difficulty with swallowing, fever, fatigue, and weight loss. In some patients, inflammation of the skin is also seen along with the muscle.
The muscles will become rigid and worn out, and frail in autoimmune myositis. Patients also experience severe pain in the muscles. Muscle weakness in autoimmune myositis is so severe that it can cause a sudden fall of a patient while walking or standing and they feel very difficult to stand up after falling. They exhibit greater discomfort in even getting up from a chair. They cannot perform their day-to-day activities and require someone to take care of them.
With reddish-purple swelling around the eyes, a heliotrope rash - also known as a dusky or purplish rash. may develop on the face. The rash can form everywhere on the body, but it is most frequently found on the hands, feet, elbows, knees, outer region of the upper thighs, and knuckles. The skin around the nails may become thicker or redder. Brownish pigmentation, scarring, or pale depigmented regions of skin may appear after the disappearance of the rash [3].
Except for the throat and esophagus, other organ involvement is rarely seen in this myositis. Heart and lungs may be affected, sometimes leading to coughing, shortness of breath, and irregular heart rhythms (arrhythmias). Inflammation of the blood vessels may sometimes lead to gastrointestinal symptoms, which include blood vomiting, black stools, and severe pain with perforation in the lining of the abdominal tract. These symptoms, if exists, are commonly seen in children, but are rare in adults [4].
Autoimmune myositis globally has an estimated prevalence of 5 to 22 per 100,000 people and an annual incidence of 1.2 to 19 per million people. In India, myositis is seen in around 4-22 people per 100,000 lakh population. Myositis is becoming more common as a result of an increase in detection rates. According to the literature, there is not much of a difference in its incidence in blacks and whites, while Hispanics have reported more cases compared to others [5, 6].
Diagnostics
The diagnosis of autoimmune myositis is based on multiple factors such as symptoms, characteristic features, various laboratory blood tests, special radiological investigations, and muscle biopsies.
Laboratory Investigations
The initial blood tests are advised to evaluate the presence or absence of myositis. Muscle weakness which is a prominent feature of myositis may occur either due to muscle problems or nerve damage. The screening tests will help to identify the disease once the symptoms of myositis appear. The initial screening tests are as follows: