AUTOIMMUNE SKIN CONDITIONS
OVERVIEW
The body reacts in a variety of ways to autoimmune disorders, which cause a person’s immune system to attack its own tissues.
Depending on the condition, an autoimmune disorder can affect a variety of organs, joints and muscles, or other bodily tissues. One tissue that’s commonly affected by autoimmune disorders is the skin.
There are several conditions that fall into this category to include: psoriasis, scleroderma, dermatomyositis, epidermolysis bullosa, and bullous pemphigoid. Individual’s with one of these autoimmune conditions have typically seen a dermatologist for the presenting symptoms that have manifested on their body.
Conditions treated can include:
INFLAMMATORY MYOSITIS
Overview
The inflammatory myopathies are a group of disorders that share a common feature of immune-mediated muscle injury. Clinical distinctions between these conditions suggest that different pathogenic processes underlie each of the following inflammatory myopathies subtypes:
- Polymyositis
- Dermatomyositis
- Necrotizing Autoimmune Myositis
- Inclusion Body Myositis
The cause of these inflammatory myopathies stems from an autoimmune reaction to the muscle tissue in genetically susceptible people. Precipitating factors that may be eliciting the event may include:
- Viruses
- Muscle injury
- Cancer
- Toxins
- Inflammation
- Infection
- Hormonal imbalances and electrolyte imbalances
Pathologic changes include:
- Cellular damage and atrophy
- Variable degrees of inflammation
- Muscles in the hands, feet, and face are affected less than other skeletal muscles
- Involvement of muscles in the pharynx and upper esophagus and occasionally the heart.
Inflammatory myositis is more common in African-Americans compared to caucasians and in woman as compared to men. Polymyositis primarily affects adults in their 30’s to 50’s. Dermatomyositis commonly affects children ages 5-15 and adults ages 45-65. Myositis can occur in combination with other autoimmune diseases. The exact cause is unknown, but we do know that it is an autoimmune disease (the body’s own immune system attacks the muscles) and in some cases the skin.
Symptoms
Myositis is characterized by the onset of chronic, severe weakness in muscles close to the trunk – the upper arms/shoulders, thighs and sometimes the neck. Weakness is due to muscle inflammation and subsequent muscle damage. While weakness is the most prominent symptom, muscle soreness can also occur. Patients may notice difficulty getting out of a chair, putting things away in overhead cabinets, or trouble climbing stairs due to weakness rather than pain.
Other symptoms can include:
- Shortness of breath from lung inflammation
- Joint pain
- Raynaud’s syndrome (finger color changes and numbness in cold weather)
- Trouble swallowing
Patients with dermatomyositis often develop:
- Several different kinds of rashes including one on the hands (Gottron’s papules)
- A violet discoloration or swelling around the eyes (heliotrope)and/or across the back and chest (shawl rash). This rash is worsened by sun exposure.
Diagnosis
The diagnosis of inflammatory myositis relies on the history (e.g. how fast are the symptoms progressing?), physical exam, lab tests (e.g. how high are the muscle enzymes or tests that measure levels of muscle inflammation in the blood?), imaging such as MRI of the thigh muscles that can reveal muscle inflammation, nerve conduction studies and a muscle biopsy. The above results will help your rheumatologist (sometimes working with a neurologist) to exclude other diseases that can cause muscle weakness and thereby mimic inflammatory myopathies. Such mimickers include:
- Thyroid disease
- Toxin-induced myopathies (e.g. associated with the use of cholesterol lowering medications called statins)
- Neuromuscular disorders (e.g. muscular dystrophy)
- Infections
- Genetic conditions such as metabolic myopathies (e.g. McArdle’s, mitochondrial myopathies)
It is important to establish the correct cause of the muscle weakness because each type of myositis is treated differently, and each has a different prognosis. Importantly, polymyositis and dermatomyositis can be associated with cancer. Your doctor will take a thorough history to make sure you are up-to-date with age-appropriate cancer screening (e.g. colonoscopy if you are over age 50).
Treatment
The initial treatment for inflammatory myopathies is steroids taken by mouth and sometimes intravenously, depending on how severe symptoms are at diagnosis. No other medication works as quickly. The eventual goal is to taper the steroids slowly and substitute a medication that is safer to take in the long term such as mycophenolate mofetil or azathioprine.
In severe cases of myositis, especially when the muscles used for swallowing are impacted, we sometimes use intravenous immunoglobulin, or IVIG, a medication given monthly by infusion.
Physical therapy is also an important part of myositis treatment to help patients regain strength.
Infusion treatment medications include:
- Rituximab (Rituxan, Truxima)
- Intravenous Immunoglobulin
Additional information about Myopathies can be found here: LINK
PSORIASIS
Overview
Psoriasis is an irritating autoimmune skin disorder that presents with rashes due to an increase of cell production. These cells under the skin raise to the skin surface and manifest in raised red plaque. There are several types of psoriasis that present in their own unique way in different regions of the body as well as having different contributing triggers. Symptoms of psoriasis flares include: red patches of skin, crusty scalp patches, and fingernail/toenail color change and pitting.
Treatment
Psorasis is generally treated initially with topical creams, light therapy, and oral medications such as methotrexate. Newer treatments for people with severe psoriasis and psoriatic arthritis are now available and have been found to be quite effective. These new biological drugs focus on controlling the immune response of the body. Infusion and injectable treatment medications include:
Additional information about Psoriasis can be found here: LINK
PEMPHIGUS VULGARIS
Overview
Pemphigus Vulgaris is a rare autoimmune condition that affects the skin and mucous membranes, causing with painful blisters and sores. Typically this condition starts in the mouth, but often involves other areas including the skin and GI tract. It can occur at any age, but it’s most often seen in people who are middle-aged or older. There is no known cause of the condition, but it is not contagious.
Diagnostics
This condition is diagnosed with a patient history, physical exam, and biopsy of the lesions.
Symptoms
- Painful blisters involving the skin and the mucosal membranes
- Difficulty swallowing or chewing
- Redness, swelling and fever
PLAQUE PSORIASIS
Overview
Plaque psoriasis, the most common form of psoriasis, causes dry, raised skin patches (plaques) covered with gray or silver scales. It may look different depending on your skin color, ranging from pink on white skin to brown or gray on brown or Black skin.
You may have just a few plaques or many. After the plaques clear up, the affected skin might temporarily be lighter (hypopigmentation) or darker (hyperpigmentation) than usual.