Treating patients with the specialized treatment they deserve
CSI provides one-on-one home infusion and specialty therapy to patients with rare and chronic disease in their homes. Becoming a CSI patient means expert-level care, support, and advocacy for your specific needs and diagnosis.
Diseases We Treat
Alpha-1 Antitrypsin (A1AT) Deficiency
Alpha-1 Antitrypsin (A1AT) Deficiency
Alpha-1 antitrypsin (A1AT) deficiency is a rare, long-term illness caused by an inherited abnormal gene mutation that primarily affects the lungs and liver. People with this condition are more likely to develop lung diseases like emphysema and liver problems such as cirrhosis. Common symptoms include liver disease, shortness of breath, chronic cough and extreme tiredness. A1AT deficiency affects about 1 in every 3,500 people. There is no cure, but early detection and proper care can help manage the condition and improve quality of life.
Ankylosing Spondylitis (AS) is a type of chronic inflammatory arthritis that mainly affects the spine. Over time, the inflammation can cause some of the small bones in the spine (vertebrae) to fuse, leading to stiffness, pain, and reduced flexibility. In severe cases, this can result in a hunched-forward posture. Common symptoms of AS include ongoing lower back pain and stiffness (especially in the morning or after periods of rest), pain in the hips, shoulders, or neck, fatigue, and reduced flexibility in the spine. AS often begins in early adulthood, and symptoms tend to develop gradually. It can also affect other joints, the eyes (causing eye inflammation), and, less commonly, organs like the heart and lungs. Early diagnosis and consistent management can make a big difference in long-term outcomes.
Chronic inflammatory demyelinating polyneuropathy is caused by damage to the myelin sheath (the fatty covering that wraps around and protects nerve fibers) of the peripheral nerves. Symptoms often include tingling or numbness (beginning in the toes and fingers), weakness of the arms and legs, loss of deep tendon reflexes, fatigue, and abnormal sensations. CIDP is closely related to Guillain-Barre syndrome and is considered the chronic counterpart of that acute disease.
Crohn’s disease is a chronic condition that causes inflammation in the digestive tract. It can affect any part of the gastrointestinal (GI) tract, but most often impacts the end of the small intestine and the beginning of the large intestine. Unlike some conditions, Crohn’s can involve all layers of the intestinal wall, and there may be healthy sections of bowel in between areas of inflammation. Common symptoms include persistent diarrhea (loose, watery, or frequent bowel movements), cramping and abdominal pain, fever, sometimes rectal bleeding, loss of appetite and weight loss and fatigue. Crohn’s disease can also affect other parts of the body outside the digestive tract, such as the joints, eyes, skin, and liver. The exact cause of Crohn’s disease is unknown. The inflammation in the GI tract causes the walls of the intestines to thicken and can lead to different types of Crohn’s depending on the area affected, which may include the small intestine, large intestine, rectum, or even the mouth.
Dermatomyositis is a rare, chronic form of myositis that is characterized by a distinctive skin rash alongside muscle weakness. It is more common in females and typically affects adults between 40 and 60 years old, as well as children aged 5 to 15. The most common symptoms include a unique rash (often reddish or purple) on the skin and muscle weakness (especially in the shoulders, hips, and thighs). Although there is no cure for dermatomyositis, treatments can help improve symptoms, including clearing the rash and restoring muscle strength.
Factor X deficiency (also known as Stuart-Prower deficiency) is a rare bleeding disorder caused by low or missing levels of a blood clotting protein called “factor X.” This condition affects both males and females equally. The severity of symptoms depends on how much factor X is present in the blood. Common signs include easy bruising, frequent nosebleeds, bleeding gums, blood in the urine and prolonged bleeding after minor injuries. Women with Factor X deficiency may also experience heavy menstrual bleeding and have a higher risk of miscarriage during the first trimester. Most cases of Factor X deficiency are acquired (not inherited). Acquired Factor X deficiency can occur due to liver disease, vitamin K deficiency, certain medications that affect clotting, or some types of cancer.
Factor XIII Deficiency is a rare bleeding disorder caused by a lack of Factor XIII, a crucial protein involved in the final stage of blood clotting. Factor XIII is an enzyme that helps stabilize blood clots by cross-linking fibrin strands, making the clot stronger and more durable. Without it, clots are weaker and break down too easily, leading to abnormal bleeding. This disease can be inherited – although very rare – or caused by autoimmune conditions, severe infections, or cancers. With regular treatment people with Factor XIII Deficiency can live normal, healthy lives.
Guillain- Barré syndrome (GBS) is a rare neurological disorder in which the body’s immune system mistakenly attacks the peripheral nerves. Early symptoms typically include weakness and tingling in the hands and feet, which can rapidly progress and lead to muscle weakness or even paralysis throughout the body. The exact cause of GBS is unknown, but in approximately two-thirds of cases, the condition is preceded by an infection, most commonly a respiratory or gastrointestinal illness, within the six weeks before symptom onset.
Hemophilia is a rare genetic bleeding disorder caused by a deficiency of certain blood clotting proteins, called factor VIII or factor IX. This deficiency leads to delayed or prolonged bleeding. People with hemophilia A have low levels of factor VIII whereas people with hemophilia B have low levels of factor IX. The severity of the disorder depends on how much clotting factor is missing. The lower the level, the higher the risk of bleeding. Bleeding can happen spontaneously or after an injury, surgery, or trauma. Bleeding inside the head or organs is especially dangerous. Repeated bleeding into joints and muscles can cause long-term damage to those areas.
Huntington’s disease (HD), also called Huntington’s chorea, is a genetic condition that causes brain cells to gradually die. Early signs often include subtle changes in mood or thinking. People may notice problems with coordination and walking soon after. As the disease progresses, jerky, uncontrolled movements become more noticeable. Over time, physical abilities decline, making it hard to move smoothly or speak clearly. Mental abilities also worsen, often leading to dementia. Symptoms can vary from person to person and usually start between ages 30 and 50, but they can appear at any age. Sometimes, symptoms show up earlier in each new generation of a family. About 8% of cases begin before age 20 and often resemble Parkinson’s disease symptoms. People with HD may not always be fully aware of how much their symptoms affect them.
Immune thrombocytopenia (ITP) is a rare autoimmune disorder where the body’s immune system mistakenly attacks and destroys healthy platelets. Platelets are blood cells that help with clotting and stopping bleeding. Common symptoms of ITP include easy or excessive bruising, small red or purple dots on the skin called petechiae, bleeding from the gums or nose, blood in urine or stool, heavy menstrual periods, and fatigue. Treatment depends on how severe the bleeding is and the number of platelets in the blood. In mild cases, treatment may not be necessary, but regular monitoring is important.
Multifocal motor neuropathy (MMN) is a rare, progressive, autoimmune disease of the nerves controlling muscle movement. It typically develops gradually, leading to asymmetrical weakness in the limbs, most often without numbness, tingling, or pain. Patients may also experience fasciculations, or small involuntary muscle twitches beneath the skin. MMN is not life-threatening and does not affect life expectancy; however, it is a long-term condition without remission. While there is no cure, treatment can slow disease progression and significantly improve function. Many patients respond well to therapy and experience only mild symptoms over extended periods. Despite this, MMN can lead to notable disability. Weakness in the hands may impair the ability to work or perform daily tasks, while foot drop can make walking or standing difficult. In more advanced cases, some individuals may require mobility aids such as canes or walkers.
Multiple sclerosis (MS) is a chronic condition that affects the central nervous system, which includes the brain, spinal cord, and optic nerves. In MS, the body’s immune system mistakenly attacks the protective covering of nerves called the myelin sheath. This damage disrupts how messages travel through the nervous system, leading to a wide range of symptoms including muscle weakness, difficulty with balance or coordination, numbness or tingling, blurred or double vision and blindness in one eye. There are different types of MS. The most common is relapsing MS, where symptoms come and go. People may experience “flare-ups” or relapses, followed by periods of recovery. In progressive MS, symptoms gradually worsen over time without clear relapses. While there is currently no cure for MS, there are treatments that can manage symptoms, treat flare-ups, and slow the progression of the disease. These treatments may include steroid medications (oral or injectable), plasma exchange therapy and newer disease-modifying medications. With the right care and support, many people with MS are able to manage their symptoms and maintain a good quality of life.
Myasthenia Gravis (MG) is a long-term autoimmune condition that causes weakness in the body’s voluntary (skeletal) muscles—those used for movement, speaking, chewing, and breathing. Muscle weakness often worsens with activity and improves with rest. MG occurs when the immune system disrupts the normal communication between nerves and muscles by blocking or destroying acetylcholine receptors, which are essential for muscle contraction. Without this signal, muscles can’t respond properly, leading to weakness. The exact cause of MG is not fully understood. In some cases, a tumor or abnormality in the thymus gland may play a role in triggering the condition. Genetics and other unknown factors may also increase a person’s risk of developing MG. While there is currently no cure, effective treatments can significantly improve symptoms and muscle strength. Some people experience temporary remission, during which symptoms disappear, and medications may not be needed. MG can affect people of any age, but it is most commonly diagnosed in, women under the age 40 and men over the age 60.
Myositis refers to a group of rare autoimmune diseases that cause muscle inflammation, leading to muscle weakness and, in some cases, muscle pain. These conditions occur when the body’s immune system mistakenly attacks healthy muscle tissue. In adults, the main types of myositis include Polymyositis (PM), Dermatomyositis (DM), Necrotizing Myopathy (NM) and Sporadic Inclusion Body Myositis (sIBM). There is also a form that affects children, called Juvenile Dermatomyositis (JDM). Common signs and symptoms of myositis include muscles weakness (often in the hips, thighs, shoulders, or upper arms), muscle pain, general tiredness and fatigue, trouble climbing stairs, difficulty standing from a seated position or reaching up, difficulty swallowing or breathing, a distinctive rash (on the knuckles, face, chest, or back), and a persistent dry cough. Because myositis symptoms can vary from person to person and may overlap with other conditions, getting an accurate diagnosis and proper treatment is essential. Early treatment can help manage symptoms and slow progression.
Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS)
Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS)
PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) and PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections) are conditions that cause a sudden and dramatic onset of symptoms such as obsessive-compulsive behaviors (OCD) or severely restricted eating in children usually before puberty. In addition to OCD or eating changes, children may experience mood swings or personality changes, anxiety, irritability, depression, motor or vocal tics, sleep disturbances, trouble with schoolwork or memory and difficulty separating from family. The main difference between the two is the trigger. PANS can be caused by various infections (viral or bacterial), immune system issues, or even environmental factors. PANDAS is a specific type of PANS that’s triggered by a strep infection, like strep throat or scarlet fever. Symptoms of PANS/PANDAS often appear suddenly, can be severe, and may come and go over time. Researchers believe that in some children, the immune system mistakenly attacks the brain, causing inflammation that affects behavior and movement. Treatment focuses on addressing the underlying infection or immune response, managing behavioral and neurological symptoms and supporting the child’s overall health and emotional well-being. A healthcare provider can help families develop a personalized care plan, which may include antibiotics, anti-inflammatory medications, therapy, and other supportive interventions.
Pemphigus and pemphigoid are rare autoimmune diseases that cause blistering on the skin and mucous membranes (such as inside the mouth). Pemphigus affects the outer layer of the skin, leading to fragile blisters and sores that can break open easily. When these blisters rupture, there is a higher risk of infection. Pemphigoid affects deeper layers of the skin and causes firmer, tense blisters that are less likely to break. Both conditions require medical care to manage symptoms and prevent complications.
Plaque psoriasis is a chronic autoimmune skin condition that causes inflammation and the rapid buildup of skin cells. This buildup leads to thick, red, scaly patches (called plaques) that most commonly appear on the elbows, knees, scalp, and lower back, but can occur anywhere on the body.
It’s called “immune-mediated” because the immune system mistakenly attacks healthy skin cells, causing inflammation and an overproduction of new skin cells. Normally, skin cells grow and shed over a month—but with psoriasis, this cycle happens in just days. Common symptoms of plaque psoriasis include raised, red patches of skin with silvery-white scales, itching or burning, and dry cracked skin that may bleed. Symptoms can come and go in flares and psoriasis is not contagious, but it is a lifelong condition that can impact quality of life. While there is no cure, many people manage their symptoms effectively with the right treatment and support.
Primary immunodeficiency diseases (PI) are a group of over 450 rare, lifelong disorders where parts of the immune system are missing or don’t work properly. These conditions are caused by inherited genetic defects. While some are present from birth or early childhood, PI can affect anyone, regardless of age or gender. Some forms of PI affect just one part of the immune system, while others affect multiple components. Despite their differences, all PI conditions share one key feature: a defect in how the immune system normally protects the body. For people with PI, infections may not go away easily or may return frequently, even with treatment. These infections can be common, severe, long-lasting, difficult to cure, and sometimes life-threatening.
Psoriatic Arthritis (PsA) is a chronic autoimmune disease that causes inflammation in the joints and often affects people who have psoriasis, a skin condition that leads to red, scaly patches. In PsA, the body’s immune system attacks healthy tissue, leading to joint pain, stiffness, and swelling, along with skin symptoms. Common symptoms of PsA include joint pain, swelling, and stiffness (especially in fingers, toes, knees, and ankles), fatigue, morning stiffness that improves with movement, swollen fingers or toes (sometimes called “sausage digits”), nail changes such as pitting or separation from the nail bed and skin plaques from psoriasis (not always present). PsA can affect people at any age, but most commonly appears between the ages of 30 and 50, especially in those with a family history of psoriasis or autoimmune conditions. Early diagnosis and treatment are important to help protect the joints and manage symptoms effectively.
Rheumatoid arthritis (RA) is a chronic autoimmune disease that mainly affects the joints. It happens when the immune system mistakenly attacks the lining of the joints, causing inflammation, pain, and swelling. Unlike osteoarthritis, which is caused by wear and tear, RA can affect people of any age and may also involve other parts of the body, including the skin, eyes, lungs, and blood vessels. Common symptoms of RA include joint pain, tenderness, and swelling (especially in the hands, wrists, and knees), stiffness, fatigue and symmetrical symptoms – the same joints on both sides of the body are often affected. RA is a progressive disease, meaning symptoms can worsen over time and may lead to joint damage or deformity if left untreated. Early diagnosis and treatment are key to managing RA effectively and preventing long-term damage.
Secondary immunodeficiency diseases are a group of disorders where the immune system is weakened or compromised due to external factors, rather than being a result of a genetic defect. These factors can include infections, medications, and other medical conditions. Unlike primary immunodeficiencies, which are inherited, secondary immunodeficiencies are acquired after birth. Despite their differences, secondary immune deficiencies share a defect in how the immune system normally protects the body and the treatment depends on the severity of the deficiency in the immune system. Treatment of the underlying cause often leads to improvement of the condition and administration of immunoglobulins may also be useful.
Stiff-person syndrome (SPS), also called Stiff-Man Syndrome (SMS) or Moersch-Woltman Syndrome, is a rare neurological disorder that causes episodes of muscle stiffness (rigidity) and painful spasms. These symptoms often begin in the back but can affect the arms, legs, and other parts of the body. The muscle stiffness may cause a person to stand or walk with a stiff or hunched posture. Episodes of spasm and stiffness can come and go but usually get worse over time. This can lead to chronic pain, difficulty moving, and in severe cases, breathing problems that require medical attention. The exact cause of SPS is unknown, but it is believed to be an autoimmune condition that affects the brain and spinal cord (central nervous system). SPS can also occur alongside other autoimmune diseases or certain types of cancer.
Ulcerative Colitis (UC) is a chronic condition that causes inflammation and sores (ulcers) in the lining of the colon (large intestine). It usually develops over time and can range from mild to severe. People with UC often go through periods of flare-ups, when symptoms are active, followed by periods of remission, when symptoms improve or go away. Signs and symptoms include diarrhea (often with blood or pus), abdominal cramping or pain, urgent or frequent bowel movements, weight loss and fatigue. UC can vary in severity and may be mild, moderate or severe, depending on symptoms. The most severe form, fulminant ulcerative colitis, is rare but serious and can cause life-threatening complications that require urgent medical attention.
Von Willebrand disease (VWD) is the most common inherited bleeding disorder, affecting about 1% of people. It happens because the body doesn’t have enough blood clotting protein called von Willebrand factor (VWF). This protein helps platelets stick together to form clots and stop bleeding. When VWF levels are low, bleeding takes longer to stop. Depending on how severe the condition is, bleeding may happen spontaneously or after an injury, surgery, or dental work. The lower the VWF level, the higher the risk of bleeding. Unlike hemophilia, VWD affects men and women equally. Most cases are mild and may go undiagnosed. However, about 3% of people with VWD have a severe form. For some women, heavy menstrual bleeding can be caused by VWD.
Specialty Therapies and Treatments Available at CSI Pharmacy
Explore our comprehensive list of specialty therapies and treatments available for the rare and chronic diseases we treat. View our complete drug list to learn more.
Going beyond the standard to reach the best outcomes for patients
At CSI, we provide more than just treatment to patients with our 360° comprehensive approach to patient care. Our team ensures patients have the therapies, resources, and support to lead to the best outcomes. No matter the diagnosis or treatment plan, our services ensure every patient feels supported throughout their journey.