TOPICAL STEROIDS

TOPICAL STEROIDS

In the general practice a typical general practitioner is always guaranteed to see a patient with skin problem who will need a topical steroid. Most of times these patients would have already used over the counter topical formulations with no relief.

As health care professionals we have to be conversant with topical steroids as they are miracle drugs when used correctly and can have dire consequences when used incorrectly. Thus, the need to write this as a step toward increasing awareness to Topical Steroids.

INTRODUCTION

Corticosteroids i.e. steroids have specific and no specific effects that are related to anti-inflammatory, immunosuppressive, antiproliferative and vasoconstrictive effects. These effects are initiated by the binding of the corticosteroid to its receptor in cytoplasm. Then this complex is translocated into the nucleus where it combines with corticosteroid responsive element in the DNA. This leads to stimulation or inhibition of adjacent genes transcription and hence regulation of the inflammatory process.

The amount of the active ingredient that is absorbed through the skin varies.

·????????Thin skin absorbs more than thick skin – skin thickness varies with body site, age and skin disorder.

·????????Occlusion increases absorption in skin folds, under dressings and greasy ointments.

·????????Small molecules are more easily absorbed through the skin than large molecules.

·????????Lipophilic compounds are better absorbed than hydrophilic compounds.

·????????Higher concentrations may penetrate more than lower concentrations.

·????????Other ingredients in the formulation may interact to increase or reduce potency or absorption rates.

When prescribing topical steroids, it is important to:

·????????Consider the diagnosis

·????????Steroid potency

·????????Vehicle

·????????Thickness of application.

·????????Total area to be treated.

·????????Frequency of application.

·????????Duration of treatment.

·????????Side effects

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• ?Indication

An accurate diagnosis is essential when selecting a steroid.

Topical corticosteroids are effective for conditions that are characterized by hyperproliferation, inflammation, and immunologic involvement. Also provide symptomatic relief for burning and pruritic lesions.

Steroids may differ in potency based on the vehicle in which they are formulated. Some vehicles should be used only on certain parts of the body:

Ointments provide more lubrication and occlusion than other preparations, and are the most useful for treating dry or thick, hyperkeratotic lesions. Their occlusive nature also improves steroid absorption. Ointments should not be used on hairy areas, and may cause maceration and folliculitis if used on intertriginous areas (e.g., groin, gluteal cleft, axilla). Their greasy nature may result in poor patient satisfaction and compliance.

Creams are mixes of water suspended in oil. They have good lubricating qualities, and their ability to vanish into the skin makes them cosmetically appealing. Creams are generally less potent than ointments of the same medication, and they often contain preservatives, which can cause irritation, stinging, and allergic reaction. Acute exudative inflammation responds well to creams because of their drying effects. Creams are also useful in intertriginous areas where ointments may not be used. However, creams do not provide the occlusive effects that ointments provide.

Lotions and gels are the least greasy and occlusive of all topical steroid vehicles. Lotions contain alcohol, which has a drying effect on an oozing lesion. Lotions are useful for hairy areas because they penetrate easily and leave little residue. A shake lotion separates into parts with time so needs to be shaken into suspension before use. Gels have a jelly-like consistency and are beneficial for exudative inflammation, such as poison ivy. Gels dry quickly and can be applied on the scalp or other hairy areas and do not cause matting.

Foams, mousses, and shampoos are also effective vehicles for delivering steroids to the scalp. They are easily applied and spread readily, particularly in hairy areas. Foams are usually more expensive.

Because hydration generally promotes steroid penetration, applying a topical steroid after a shower or bath improves effectiveness. Occlusion increases steroid penetration and can be used in combination with all vehicles. Simple plastic dressings (e.g., plastic wrap) result in a several-fold increase in steroid penetration compared with dry skin. Occlusive dressings are often used overnight and should not be applied to the face or intertriginous areas. Irritation, folliculitis, and infection can develop rapidly from occlusive dressings, and patients should be counseled to monitor the treatment site closely.

Potency

There are seven groups of topical steroid potency, ranging from ultra high potency (group I)to low potency (group VII.

Brand name agents may be more expensive, which may reduce patient compliance. This should be considered when choosing steroid agents. Physicians should also be aware that some generic formulations have been shown to be less or more potent than their brand-name equivalent.

Low-potency steroids are the safest agents for long term use, on large surface areas, on the face or areas of the body with thinner skin, and on children. More potent agents are beneficial for severe diseases and for areas of the body where the skin is thicker, such as the palms and bottoms of the feet. High- and ultra-high potency steroids should not be used on the face, groin, axilla, or under occlusion, except in rare situations and for short durations.

Hints:

·????????Choose strength of corticosteroid based on pathogenesis of disease; hyperproliferative disorders require class III or IV agents.

·????????Watch for tachyphylaxis; application more than b.i.d. is almost never correct.

·????????Use with care on face and in intertriginous areas; exceed class II only with definite indications (localized bullous pemphigoid, nonresponsive chronic cutaneous lupus erythematosus).

·????????Never go above class II in children.

·????????Avoid using corticosteroids in infectious processes (pyoderma, tinea) unless the underlying disease is being simultaneously treated.

·????????Always think about steroid-sparing approaches (phototherapy, tar, retinoids, vitamin D analogues, calcineurin inhibitors, dithranol, urea).

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Frequency of Administration and Duration of Treatment

Once- or twice-daily application is recommended for most preparations. More frequent administration does not provide better results.

Chronic application of topical steroids can induce tolerance and tachyphylaxis. Ultra-high-potency steroids should not be used for more than three weeks continuously. If a longer duration is needed, the steroid should be gradually tapered to avoid rebound symptoms, and treatment should be resumed after a steroid-free period of at least one week. This intermittent schedule can be repeated chronically or until the condition resolves.

Side effects are rare when low- to high-potency steroids are used for three months or less, except in intertriginous areas, on the face and neck, and under occlusion.

Most patients are not instructed on how to apply topical steroids and this leads to overdose or underdose application leading to unsatisfactory results.

The amount of steroid the patient should apply to a particular area can be determined by using the fingertip unit method. A fingertip unit is defined as the amount that can be squeezed from the fingertip to the first crease of the finger.

One hand-size area (i.e., the area of one side of the hand) of skin requires 0.5 fingertip units or 0.25 g of steroid. The amount dispensed and applied should be considered carefully because too little steroid can lead to a poor response, and too much can increase side effects.

To know how much steroids the patient has to use the following table is informative:

Side Effects

Prolonged use of topical corticosteroids may cause side effects. To reduce the risk, the least potent steroid should be used for the shortest time, while still maintaining effectiveness.

The most common side effect of topical corticosteroid use is skin atrophy. All topical steroids can induce atrophy, but higher potency steroids, occlusion, thinner skin, and older patient age increase the risk. The face, the backs of the hands, and intertriginous areas are particularly susceptible. Resolution often occurs after discontinuing use of these agents, but it may take months.

Other side effects from topical steroids include permanent dermal atrophy, telangiectasia, and striae.

Topical steroids can also induce rosacea, which may include the eruption of erythema, papules, and pustules or steroid dermatitis. ?It is to be treated with a 10-day course of tetracycline (250 mg four times daily) or erythromycin (250 mg four times daily).

Topical applications of corticosteroids can also result in hypopigmentation. This is more apparent with darker skin tones, but can happen in all skin types. Repigmentation often occurs after discontinuing steroid use.

Steroids can induce a contact dermatitis in a minority of patients, but many cases result from the presence of preservatives, lanolin, or other components of the vehicle. Nonfluorinated steroids e.g., hydrocortisone are more likely to cause a contact dermatitis.

Topically applied high- and ultra-high potency corticosteroids can be absorbed well enough to cause systemic side effects. Hypothalamic-pituitary-adrenal suppression, glaucoma, septic necrosis of the femoral head, hyperglycemia, hypertension, and other systemic side effects have been reported.

Side effects occur more often with higher potencies.

Special Considerations

Children often require a shorter duration of treatment and a lower potency steroid. Application of topical steroids in children should be limited to the least amount required for effective results.

Chronic corticosteroid therapy may interfere with growth and development in children.

Children with atopic dermatitis who require steroid application on large surface area for prolonged period are at increased risk of HPA (hypothalamus-pituitary axis) suppression.

When the diagnosis is unclear, when standard treatments fail referral to a dermatologist is recommended.

Topical steroids can induce birth defects in animals when used in large amounts, under occlusion, or for long duration. They have not been shown to do so in humans, and are classified by the U.S. Food and Drug Administration as pregnancy category C.

It is unclear whether topical steroids are excreted in breast milk; as a precaution, application of topical steroids to the breasts should be done immediately following nursing to allow as much time as possible before the next feeding.

The normal presentation of superficial infections can be altered when topical corticosteroids are inappropriately used to treat bacterial or fungal infections. Steroids interfere with the natural course of inflammation, potentially allowing infections to spread more rapidly.

Elderly population also has thin skin with increased absorption of topical steroids and thus the need for consideration in these patients as that for infants.

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Inflammation gets suppressed, while fungal or bacterial growth gets flourished due to steroid therapy. Consequently, tinea infections get transformed into unrecognizable cutaneous eruptions which are termed as tinea incognito. The application of high-potency steroids can induce a deep tissue tinea infection known as a Majocchi granuloma. There may be aggravation of cutaneous candidiasis and herpes infection.

Combinations of antifungal agents and corticosteroids should be avoided to reduce the risk of severe, persistent, or recurrent tinea infections. Any rash treated with topical steroids that worsens or does not significantly improve should be reevaluated for the possibility of an un diagnosed infectious etiology.

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CONCLUSION

Use of steroids must qualify the principle of 4D which is as under:

? Diagnosis: One should ensure a correct diagnosis before using steroids. Treating a dermatophyte infection with steroid is a common mistake.

? Drug priority: If we have better alternative drug than steroid, then we should avoid the use of steroid, e.g., for the management of psoriasis (except in certain circumstances) we have many nonsteroid effective drugs which deserve priority over steroids. Steroids show rebound phenomenon and may flare-up psoriasis.

? Dose: Dose should be optimum. One should start steroids in a proper effective dose for that condition. Initial under dose may have to be increased later on. It would increase the amount of total steroids given and their side effects.

? Duration: Duration should be optimum. Once the desired effects are achieved, steroids should be tapered off according to the clinical response. They should not be used for longer periods unnecessarily.

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?REFERENCES:

1.??????Thieme Clinical Companions Dermatology 5th German edition, W Sterry et al 2005. Pg 40-44.

2.??????Essentials in Dermatology, Venereology & Leprology 1st edition, Ramesh Bansal 2015. Pg 406-413.

3.??????Choosing Topical Corticosteroids, Volume 79, Number 2. Jonathan F and Allen R, 2009. American Family Physician Web site.

4.??????Dermatology Made Easy 1st Edition, Amanda Oakley 2017. Pg 378-380

5.??????Fitzpatrick’s Dermatology in General Medicine, 7th Edition. Klaus W et al. 2008. Pg 2091.