Corticosteroids - What they are used for 

Corticosteroids are widely used and are commonly prescribed to:

• help reduce inflammation (anti-inflammatory)
• suppress the immune system (immunosuppressant)
• replace hormones that are not being produced by the body due to a health condition (replacement therapy)

These three uses are discussed in more detail below.

Anti-inflammatory uses

Inflammation occurs when the immune system tries to prevent an infection from spreading. The immune system is the body’s natural defence against infection and illness. It sends special chemicals to the site of the infection, causing it to become inflamed and swollen.

However, in allergic reactions, the immune system regards harmless substances, such as pollen, as harmful. This triggers inflammation. Corticosteroids can help treat a range of allergic conditions, including asthma and allergic rhinitis (hay fever). These are usually treated using inhalers, although a short course of corticosteroid tablets may be recommended if you have a particularly severe flare-up of symptoms.

Corticosteroids are also often used to treat a number of allergic skin conditions, such as:

• urticaria – commonly known as nettle rash
• atopic eczema – which mostly affects children

Corticosteroid creams and lotions are often used to treat these types of skin conditions, although steroid tablets may be needed if your symptoms are particularly severe.

Short courses of corticosteroid tablets are sometimes used to treat people with chronic obstructive pulmonary disease (COPD). COPD refers to a collection of lung conditions that cause breathing problems.

Some people with COPD have periods where their lungs and airways become very inflamed, often as a result of infection. Corticosteroid tablets help reduce the inflammation and help with breathing.

Sometimes, joints, muscles and tendons can become persistently inflamed as a result of injury or over-use. In such cases, a corticosteroid injection may be recommended to help reduce the inflammation.

Immunosuppressant uses

In some illnesses, the immune system malfunctions and attacks healthy tissue. These are known as autoimmune conditions. Corticosteroids can be used to help treat a range of autoimmune conditions including:

• rheumatoid arthritis – the immune system attacks the joints
• lupus – the immune system attacks the skin and the joints
• Crohn’s disease – the immune system attacks the digestive system
• ulcerative colitis – the immune system attacks the colon
• giant cell arteritis – the immune system attacks the arteries
• polymyalgia rheumatica – the immune system attacks the muscles, particularly in the neck and shoulders
• multiple sclerosis – the immune system attacks the nerves

Replacement therapy

Corticosteroids are similar to the natural hormones that are produced by the adrenal glands. These are two small, triangular-shaped glands located above the kidneys. These hormones play an important role in regulating the body’s metabolism (the process of converting food into energy).

Corticosteroids are also often used to treat Addison's disease. This is where the adrenal glands do not produce the correct amount of hormones. Symptoms of Addison’s disease include:

• severe fatigue
• hypotension (low blood pressure)
• the need to urinate often