Steroids and the Skin

Topical corticosteroids have been used for about 50 years and their introduction was a milestone in dermatology. They are used to treat inflammatory skin conditions by suppressing the inflammatory reaction and relieving symptoms. However, they are not curative and attempts to increase potency have often been associated with more adverse effects. The emphasis should be on limited, selective, and careful use with clear explanation and instruction to patients.

• Eczema - the most important because it is very common both in adults and children (affecting 15-20% of school children and 2-10% of adults). Children are most at risk from misuse and adverse effects. See Atopic Eczema article.
• Contact dermatitis
• Seborrhoeic dermatitis (antifungals probably more appropriate¹)
• Insect stings
• Eczema associated with infection - with caution
• Psoriasis - with caution
• Other inflammatory skin conditions including: discoid lupus erythematosus; lichen planus under specialist supervision.

• Randomised controlled trials (RCTs) show treatment effect over placebo for atopic eczema.²
• There is consensus that topical steroids are effective for seborrhoeic dermatitis of the scalp in adults.¹ There were however no RCTs comparing steroids.
• Short courses of steroids used episodically are effective by consensus, for treating seborrhoeic dermatitis of the face and body in adults.³
• In psoriasis evidence of potent steroid efficacy similar to vitamin D derivatives is available but evidence of side effects and flares of the disease on withdrawal were also found.^4,5,6,7

• Establish correct diagnosis. Does the lesion fit diagnostic criteria of, for example atopic eczema?⁸
• Consider diagnoses which require different treatment approach. For example: scabies, bacterial infection (suggested by crusting and weeping) herpes infection (suggested by vesicles or punched out erosions).
• Consider wider management issues:
  • Aggravating factors
  • Previous treatments
  • Impact on quality of life
  • Other medications
  • Growth chart in children

Referral might be considered, occasionally before treatment if:

• Diagnosis unclear
• Certain diagnoses where distribution and severity require referral
• Severe infection suspected e.g. eczema herpeticum
• Lack of response to treatment of primary condition (see guidance below)
• Failure of treatment for secondary infection
• Contact dermatitis requiring patch testing
• Additional advice or treatments required
• To consider use of immunomodulatory agents (such as tacrolimus and pimecrolimus)
• Dietary factors suspected

Anecdotally and within articles written about use of topical steroids there are a number of common criticisms, implied or overt, of general practitioner's prescribing of topical steroids.^9,10 This may reflect what is seen by specialists receiving referrals rather than what is going on more widely. Criticism includes:

• Prescribing inappropriate quantities. Usually quantities prescribed are too small.
• Prescribing an inappropriate strength of steroid and length of treatment. (The BNF classifies topical steroids as mild, moderate and potent).
• Prescribing emollients inadequately. These are not prescribed often enough, in sufficient quantity or with correct instructions.
• Prescribing generally with inadequate instructions in the use of both emollients and topical steroids.

Guidance has been issued with this in mind.^8,11 There may be a place for use of printed information (Including detail of how to use emollients and topical steroids) and education involving practice nurses to help improve efficacy of treatments and information for patients. Examples can be obtained from the British Association of Dermatologists⁸ and the National Eczema Society.

Guidance can be summarised as follows:

• Choice of formulation is important:
  • Creams are best for weeping or moist areas.
  • Ointments are best for dry scaly or lichenified areas.
  • Lotions are useful for larger or hair bearing areas.
  • Occlusive dressings increase absorption. Caution and close supervision is required.
• Potency of steroid should be matched to age, disease severity and site. For example:
  • Face, genitals and flexures:
    • Skin is thin and self occludes within the skin fold, thus increasing absorption.
    • Milder steroids should therefore be prescribed.
  • Eyelids:
    • Skin is thin. Restrict to intermittent mild steroid for no more than 14 days and avoid eye contact.
    • Over age 35 beware risk of glaucoma if used for more than 14 days and monitor IOPs.
  • Palms, soles of feet and scalp:
    • Skin is thicker. Stronger steroids required.
    • Consider occlusive techniques.
  • Trunk and limbs in adults:
    • Use weakest strength required to achieve control within 14 days as judged by severity of the inflammation and prior response to treatment.
  • Children:
    • Use weaker steroids especially when large area to be treated.
    • Consider specialist referral if moderate strength steroids are needed to maintain control.
• Duration of treatment:
  • Treatment gives only symptomatic relief and duration of treatment should be limited to a week for acute conditions.
  • In more chronic conditions use for 4-6 weeks to achieve remission (for example in chronic eczema).
  • Short bursts of stronger steroids can be used to gain control over a few days.¹²
• Quantity of steroid:
  • Give specific information on the quantity to be applied (as too much risks side effects and too little may be ineffective). This can be specified according to the calculation that one FTU (finger tip unit, or length squeezed from tube between tip of finger and first skin crease) is enough to cover an area about twice the area of the palmar aspect of the hand (and weighs approximately 500 mg).
  • No more than twice daily should be applied and the NICE guidelines¹³ suggest that once daily may be as effective as more frequent applications. This may also reduce side effects.
  • Specific guidance on how much cream or ointment should be prescribed is helpful. For example, a guide to quantities from the BNF for an acute eczema flare up in adults is:

    Face and neck	30g
    Both hands	30g
    Scalp	30g
    Both arms	60g
    Both legs	100g
    Trunk	100g
    Groin and genitalia	30g

• Use of emollients¹⁴:
  • Topical steroids should not be used for emollient effect.
  • Emollients should be applied at least 30 minutes before the topical steroid.
  • Frequent and intensive emollient use in eczema will reduce the amount of steroid needed.
• Monitoring of treatment:
  • Regular review of treatment should be undertaken to ensure that minimum strength required is being used and to check for side effects.
  • Care should be taken to follow up more closely use of stronger steroids, children, and in areas of the body where skin is thin.
  • Immunomodulatory agents such as tacrolimus and pimecrolimus are now available as an alternative to topical steroids. These are as effective but more expensive. Initiation usually requires referral.

Topical corticosteroids are contraindicated in:

• Untreated infection (bacterial, fungal and viral)
• Acne rosacea
• Perioral dermatitis
• Extensive plaque psoriasis

These may be systemic or local.^15,16,17

• Systemic side effects:
  • These are more likely with more potent steroids, larger quantities, more frequent application and where absorption is greatest (certain sites of the body and occlusion enhance absorption).
  • Children by virtue of skin type, surface area to weight ratio and disease severity are more at risk of systemic side effects and should be monitored closely. The risk of growth retardation exists and growth should be monitored under specialist supervision where moderate strength steroids are required regularly.
  • Safe weekly limits to avoid systemic side effects have been suggested:¹⁸

    Treatment period in months	Mild to moderate	Potent	Very potent
    Less than 2 months	100g	50g	30g
    2-6 months	50g	30g	15g
    6-12 months	25g	15g	7.5g

• Localised adverse effects:
  • Effects such as skin thinning are unlikely to occur in less than 4 weeks in mild to moderate strength steroids but can occur with potent steroid within 1-3 weeks. This will often, but not always, reverse within 4 weeks if stopped.
  • If potent steroids are required for control of inflammation for more than 7 days in a 5 week period referral is recommended because of the risk of local side effects.¹¹