Corticosteroids

Created 2008.

Learning objectives

• Prescribe corticosteroids appropriately and safely for inflammatory skin diseases

Clinical use

Topical steroids are very important drugs used to control inflammatory skin diseases, particularly dermatitis.

In general, use a potent preparation short term (a few days or weeks) and weaker preparation for maintenance between flare-ups. Pulse therapy refers to the application of a corticosteroid for 2 or 3 consecutive days each week or two. This is useful for maintaining control of chronic diseases such as psoriasis. Generally a milder topical steroid or non-steroid treatment is used on the in-between days.

Prescribe in an appropriate base:

• Ointment for dry skin
• Cream for flexures, face and blisters
• Lotion for hairy areas

And in adequate quantities:

• A single whole body application requires 10g for a baby and 30g for an adult; a 10-day course will consume 300g (if that hasn't worked, refer for dermatological assessment)
• One hand uses 0.5g per application; 30g is adequate for hand dermatitis for one month

Pharmacology of topical steroids

• Topical steroids are classified according to their strength (see Table 1)
• The rate of absorption of topical steroids depends on the thickness of the stratum corneum
• Absorption is greater if in an ointment base, in the presence of a keratolytic agent, and under occlusion e.g. with cling-film wrapped around the affected area
• Percutaneous absorption of topical steroids may rarely result in Cushing syndrome
• Prolonged application of potent topical steroids may cause cutaneous atrophy, purpura and if applied to the face, perioral dermatitis
• Tachyphylaxis is a particular problem in the treatment of psoriasis; potent topical steroids lose their efficacy and the underlying skin disease increases in extent and severity
• Intralesional injection of corticosteroids may cause subcutaneous atrophy or abscess

Corticosteroids are absorbed at different rates depending on the thickness of the stratum corneum. A mild topical steroid that works on the face may achieve little on the palm. But a potent steroid may quickly cause side effects on the face.

For example:

• Forearm absorbs 1%
• Armpit absorbs 4%
• Face absorbs 7%
• Eyelids and genitals absorb 30%
• Palm absorbs 0.1%
• Sole absorbs 0.05%

Absorption is greater in an ointment base, in the presence of a keratolytic agent such as salicylic acid and under occlusion.

Adverse effects of topical steroids

Percutaneous absorption of topical steroids may rarely result in systemic side effects. More than 50g of clobetasol propionate or 500g of hydrocortisone each week can result in adrenal gland suppression in an adult and/or eventually Cushing syndrome. Proportionally smaller quantities may affect children.

Local side effects of topical steroids are more common and include:

• Skin thinning (atrophy) and stretch marks (striae).
• Easy bruising (senile purpura) and tearing of the skin (fragility).
• Telangiectasia.
• Perioral dermatitis (erythematous papules around the mouth).
• Contact allergy to the steroid molecule itself or another ingredient.

The risk of these side effects depends on the strength of the steroid, the length of application, the site treated, and the nature of the skin problem. A potent steroid cream applied to the face results in side effects within a few weeks. 1% hydrocortisone cream on hands and feet would be most unlikely to cause problems.

In children, cutaneous thinning secondary to potent topical steroids appears to be at least partly reversible and is rarely a problem.

Striae 

Steroid atrophy and purpura 

Perioral dermatitis 

Intralesional steroid

The only available injectable steroid is triamcinolone acetonide as 1ml ampoules of 10mg/ml or 40mg/ml. Blebs of 0.05 to 0.1ml can be cautiously injected into the dermis at 1cm intervals to a maximum of 1 to 2ml, for the following inflammatory skin diseases:

• Hypertrophic or keloid scarring
• Localised granulomas particularly granuloma annulare
• Alopecia areata affecting eyebrows or scalp
• Lichen simplex or lichenified psoriasis.

Injections should not be repeated for 4 to 6 weeks. The main complication, atrophy, arises if the injection is delivered into subcutaneous tissue instead of the dermis. Infection, sterile abscesses and hypopigmentation occur rarely.

Adverse effects of intralesional steroids

Subcutaneous atrophy

Atrophy and hypopigmentation

Systemic steroids

Patients prescribed systemic steroids for skin diseases should be carefully advised of potential risks and adverse effects.

Acute dermatoses
Systemic steroids may be used to treat acute severe skin diseases such as plant contact allergy, autosensitisation dermatitis, flares of atopic dermatitis, Sweet disease and drug hypersensitivity syndrome. They may also be used initially to gain control in extensive or symptomatic lichen planus. Acute urticaria is better managed with oral antihistamines but if they are not effective many practitioners prescribe systemic steroids to provide the patient with short-term relief.

In general, an adult patient should be treated with 40 mg of prednisone for as long as it takes to control the skin disease properly and then it should be tapered. For acute contact dermatitis, it can be discontinued as soon as the rash is controlled (about 7 to 10 days) providing the patient is no longer in contact with the source of the eruption. Courses of three or four weeks may be adequate for other forms of dermatitis and Sweet disease.

The use of intermittent intramuscular triamcinolone 40 to 80 mg stat has fallen out of favour. It is more difficult to adjust doses, corticosteroid side effects may be as troublesome as with oral prednisone, and subcutaneous atrophy is a relatively common complication. The once-monthly dose of triamcinolone acetonide is the same as would be used for prednisone per day.

Chronic dermatoses
Chronic autoimmune skin conditions should only be treated with systemic steroids (usually oral prednisone) if they are resistant to other medications and after careful consideration of the risk / benefit ratio. Examples may include:

• Immunobullous diseases
• Cutaneous vasculitis
• Cutaneous lupus erythematosus resistant to antimalarial therapy
• They are occasionally appropriate for chronic dermatitis including pompholyx, discoid eczema and atopic dermatitis

Systemic steroids are best avoided in psoriasis as they can make control of the disease very difficult, particularly after steroid withdrawal. In rare cases of severe psoriasis, they may be the only appropriate drug but should only be prescribed under the supervision of an experienced dermatologist.

Starting dose is usually 40 mg of prednisone with breakfast for two to four weeks. If the disease is poorly controlled, the dose may be increased to 60 to 80 mg daily but blood pressure, serum glucose and side effects will require careful monitoring. Once controlled, the dose of steroids should be reduced by half for at least two weeks. Further reduction will depend on the break-through dose, the severity of the underlying skin disease and the availability or efficacy of steroid-sparing agents. The dose of long term prednisone should be as low as possible, as for other chronic diseases, and if possible taken on alternate days.

If steroids are likely to be used for more than a few weeks, consider bone protection. Arrange a DEXA bone density scan. Prescribe calcium, vitamin D or in high risk individuals, a bisphosphonate from the first day of treatment.

Patient information
Patients on long term steroids should be told:

• Smoking markedly increases the risks of steroid-induced osteoporosis. 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.
• Not to stop the prednisone abruptly and to advise all their health professionals that they are taking it.
• Avoid oral live polio vaccination. It is safe to have other routine immunisations. Annual influenza vaccination is worthwhile.
• 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. This has rarely been reported after short courses of prednisone (4 weeks).
• The medication increases the chance of serious diseases including infections, avascular necrosis of the femoral head, diabetes mellitus, hypertension, heart failure, glaucoma, cataracts and peptic ulceration.
• They can expect body fat redistribution: moon face, buffalo hump and truncal obesity.
• Salt retention may result in headache, leg swelling, raised blood pressure, weight increase and heart failure.
• They may develop shakiness, tremor and psychological effects including insomnia, mood changes, increased energy, excitement, delirium or depression.
• Potential side effects from reducing the dose include tiredness, headaches, muscle and joint aches and depression.

Cutaneous side effects of systemic steroids may include:

• Dermal atrophy resulting in purpura, fragility and striae
• Steroid acne (Malassezia folliculitis): monomorphic papulopustules on face, chest and upper back
• Rosacea
• Wound infections and delayed healing.

Activity

Discuss the diagnosis and management of contact allergy to topical steroids.