Resident Editor: Juliana Macri, M.D..

Faculty Editor: Ryan Arakaki, M.D.

Background

• Class refers to the strength of topical steroids and is determined by both potency and vehicle.
• The steroid class selected depends on the affected body part and the condition being treated (lower classes on the face or intertriginous areas; higher classes on the extremities, hands, or feet)
• Indications for topical steroids include conditions with hyperproliferation, inflammation, and immunologic involvement. Topical steroids also relieve burning and pruritic symptoms
• Use on a fungal infection will exacerbate the condition, so perform a skin scraping with KOH before prescribing. Avoid anti-fungal – steroid combination

Steroid vehicles and application:

• Ointments:
• Petroleum-based, greasy (patients often dislike)
• Better for hydration, occlusion, and absorption
• Useful for dry, thick, hyperkeratotic lesions
• Avoid hairy and intertriginous areas (can cause skin maceration and folliculitis)
• Creams:
• Water suspended in oil
• More cosmetically acceptable but less potent than ointments
• Drying effect
• Often contain preservatives (which can irritate and cause an allergic reaction)
• Lotions:
• Minimally greasy and occlusive
• Contain alcohol (drying effect good for oozing lesions, may cause stinging/burning)
• Useful for hairy and intertriginous areas given good penetration with minimal residue
• Gels:
• Alcohol-based with a jelly-like consistency
• Dries quickly
• Useful for hairy or oily areas (like scalp) or wet lesions (bullae)
• Application tips
• Hydration and occlusion promote steroid penetration
• Applying after bathing improves the effectiveness
• Occlusion with plastic wrap can increase penetration several-fold (good for extremities). Recommend using overnight, but not on the face or intertriginous areas, and shortening duration of use

Side Effects From Topical Steroids

• Atrophic changes (increased risk with higher potency, occlusion, thin skin, and age)
• Easy bruising, increased fragility, striae, ulceration
• Can be mitigated by concurrent topical tretinoin (Retin-A) 0.1% if chronic use required (though difficult to adhere to, not commonly used)
• Infections (especially if inappropriate treatment of fungal or bacterial infection)
• Aggravation of cutaneous infection, masked infection (tinea incognito), secondary infections
• Re-evaluate diagnosis if the rash worsens or does not improve with steroids
• Miscellaneous
• Contact dermatitis (often due to additives, rarely can have an allergy to the steroid agent itself)
• Steroid-induced acne, rosacea
• Delayed wound healing
• Hypertrichosis (hirsutism)
• Hypopigmentation
• Systemic effects
• High-dose steroids may have enough absorption to cause systemic effects (e.g. hypertension, hyperglycemia, glaucoma) and HPA axis suppression, especially when used on a broken skin barrier.

Prescribing Considerations

• Consider generic availability and patient’s formulary to increase adherence. Counsel patient to reach out for alternative if cost-prohibitive.
• Must consider potency, frequency, and duration of therapy
• Potency
• Low potency steroids preferred for long-term use, large surface areas, on the face, intertriginous areas, and other areas with thinner skin
• High potency steroid can be used in severe disease, areas with thicker skin (e.g. palms, soles). Never use on face, intertriginous areas. Caution with occlusion.
• Frequency
  • Once or twice daily for most preparations. Titrate to a minimum frequency that still provides relief
• Duration
  • Be aware of side effects, tolerance, and tachyphylaxis with prolonged use
  • Do not use ultra-high potency for >3 weeks at a time. Use intermittent schedule with tapering and one-week steroid-free interval, as needed
  • Low-high potency steroids should be limited to <3 months. Shorter if with occlusion or on thin skin.
  • Anticipate the amount required for appropriate treatment and prescribe accordingly (see Table 8).

Table 7: Classes of Topical Steroids

Note: common preparations in bold

Fingertip Unit

1 FTU = 0.5g = Amount that can be squeezed from the fingertip to the first crease of the finger

Enough to cover 2 hands (one side) worth of skin

Face and neck = 2.5 FTU

Trunk (front or back) = 7 FTU

Arm = 3 FTU

Leg = 6 FTU

Foot = 2 FTU

Table 8: Required Steroid Amount/Week

References

Miller, JA, Munro DD.  Topical corticosteroids: clinical pharmacology and therapeutic use. Drugs 1980;19:119.

Ference JD, Last AR. Choosing Topical Corticosteroids. Am Fam Physician. 2009;79(2):135-140.