Systemic corticosteroids (glucocorticoids) are synthetic derivatives of the natural steroid, cortisol, which is produced by the adrenal glands. They are called "systemic" steroids if taken by mouth or given by injection as opposed to topical corticosteroids, which are applied directly to the skin. Systemic steroids include prednisone, prednisolone, methylprednisolone, betamethasone, dexamethasone, triamcinolone and hydrocortisone.
Systemic steroids work in the same way as natural cortisol, and are prescribed for a large number of serious diseases. Skin conditions treated with steroids include blistering diseases such as pemphigus and pemphigoid, and severe forms of dermatitis.
Natural cortisol has important effects in the body, including regulation of:
* Protein, carbohydrate, lipid and nucleic acid metabolism
* Inflammation and immune response
* Distribution and excretion of water and solutes
* Secretion of adrenocorticotrophic hormone (ACTH) from the pituitary gland.
What doses of systemic steroids are used?
Systemic steroids vary in strength. The beneficial effects as well as the side effects are proportional to the dose taken. Steroid dose is commonly characterised into:
* Low dose (e.g. <10mg/day>20mg/day of prednisone, sometimes more than 100mg/day).
Treatment for less than one month is considered short term treatment. Treatment continuing for more than 3 months is regarded as long term, and results in the majority of undesirable side effects.
Corticosteroids for a few days or weeks are relatively safe, e.g. for acute dermatitis.
One must always carefully assess the severity of the underlying disorder, the gains that can be expected from corticosteroid therapy, and the risks. Excessive corticosteroid use is one of the causes of Cushing's syndrome.
Skin problems from systemic steroids
The skin is prone to the following adverse effects from prolonged courses or high doses of systemic steroids. These may include:
* Increased risk of skin infections such as bacterial infections (e.g. cellulitis) and fungal infections (e.g. tinea, candida)
* Skin thinning resulting in easy bruising (purpura), skin tearing after minor injury, slow healing, and stretch marks (striae).
* Acne: clusters of small spots on face, chest and upper back.
* Subcutaneous lipoatrophy (loss of fat under the skin surface) from injected steroid that does not go deep enough into the muscle.
Moon face Purpura
Easy bruising Moon face
Fragile skin Purpura
Acne Moon face
Side effects from a short course of systemic steroids
If systemic steroids have been prescribed for one month or less, side effects are rarely serious. However the following problems may arise:
* Sleep disturbance
* Increased appetite
* Weight gain
* Psychological effects, including increased or decreased energy
Rare but more worrisome side effects of a short course of corticosteroids include: mania, psychosis, heart failure, peptic ulceration, diabetes and aseptic necrosis of the hip.
Side effects from a longer course of systemic steroids
Nearly everyone on systemic steroids for more than a month suffers from some adverse effects. These may include any of the following problems, which are not listed in any particular order of importance.
* Reduction of your own cortisol production. During and after steroid treatment, the adrenal gland produces less of its own cortisol, resulting from hypopituitary-pituitary-adrenal (HPA) axis suppression. For up to twelve months after the steroids are stopped, the lack of steroid response to stress such as infection or trauma could result in severe illness.
* Osteoporosis (thinning of the bones) particularly in smokers, postmenopausal women, the elderly, those who are underweight or immobile, and patients with diabetes or lung problems. Osteoporosis may result in fractures of the spine, ribs or hip joint with minimal trauma. These occur after the first year in 10-20% of patients treated with more than 7.5mg prednisone daily. It is estimated that up to 50% of patients using oral corticosteroids will develop bone fractures.
* Reduction in growth in children, which may not catch up when the steroids are discontinued (but it usually does).
* Muscle weakness, especially of the shoulder muscles and thighs.
* Rarely, avascular necrosis of the femoral head (destruction of the hip joint).
* Precipitation or aggravation of diabetes mellitus (high blood sugar).
* Increase in circulating blood fat (triglycerides).
* Redistribution of body fat: moon face, buffalo hump and truncal obesity.
* Salt retention: leg swelling, raised blood pressure, weight increase and heart failure.
* Shakiness and tremor.
* Eye disease, particularly glaucoma (increased intraocular pressure) and posterior subcapsular cataracts.
* Psychological effects including insomnia, mood changes, increased energy, excitement, delirium or depression.
* Headaches and raised intracranial pressure.
* Increased susceptibility to internal infections, especially when high doses are prescribed (e.g. tuberculosis). Avoid oral live polio vaccination. It is safe to have other routine immunisations.
* Peptic ulceration, especially common in those also taking anti-inflammatory medications.
* There are also side effects from reducing the dose; these include tiredness, headaches, muscle and joint aches and depression.
If you have been prescribed systemic steroids, make sure you understand how to take the medicine safely. Regular monitoring during treatment may include:
* Blood pressure
* Body weight
* Blood sugar
Discuss any side effects you may experience with your doctor.
Prevention of osteoporosis
Specific measures to reduce the chance of steroid-induced osteoporosis should be considered for patients that have taken or are expected to take 10 mg or more of prednisone or prednisolone each day for a period of three months or longer.
A DEXA bone scan measures bone density. Bone density gives an indication of the risk of fracture due to bone loss. Arrange to have a scan as you start systemic steroids, and it should be repeated every year or as recommended by your physician.
Preventative treatment includes the following medications:
* Calcium tablets 500- 1000 mg per day
* Vitamin D in various forms including monthly cholecalciferol 50,000 units (1.25 mg)
* Oestrogen i.e. hormone replacement tablets in females that have had early menopause
* Bisphosphonates (alendronate, etidronate); these are prescribed for high risk patients.
Treatment is most effective when started at the same time as the steroids, as most bone loss occurs within the first few months. This is most important for people taking more than 7.5mg of prednisone (or the equivalent dose of another oral corticosteroid) for three months or more.
If you smoke, stop. Consume minimal alcohol. Take regular weight bearing exercise e.g. walking for 30 to 60 minutes each day.
Reducing the dose of systemic steroids
Do not suddenly stop systemic steroids; your doctor will explain how to gradually come off them (particularly important if you have been on them for more than six weeks). For example:
* No tapering is necessary if the course of steroids has been for less than one week.
* After taking a dose of 30 mg or more per day for 3-4 weeks, reduce the dose by 10 mg or less per day, taking days to weeks to stop altogether.
* A much slower reduction in dose may be required if the medication has been taken for several months.