Topical Steroid Potency Charts: Understanding Potency Levels to Treat Skin Conditions Safely

Understanding Topical Steroid Potency

Topical steroids are commonly prescribed medications used to treat various skin conditions like eczema, psoriasis, and dermatitis. They work by reducing inflammation and suppressing the immune system in the applied area. Topical steroids come in a range of potencies or strengths, from mild over-the-counter hydrocortisone creams to prescription-only super-high potency ointments.

Knowing the potency level of topical steroids is important to get the right strength needed for your condition without increasing the risk of side effects. This article provides an overview of topical steroid potency charts and how they are used to guide topical steroid treatment.

What is Topical Steroid Potency?

Topical steroid potency refers to the strength or concentration of the steroid ingredient in a topical preparation. In the United States, topical steroids are categorized into 7 classes based on potency from lowest to highest:

Class 1: Super Potent
Class 2: Potent
Class 3: Upper Mid-Strength
Class 4: Mid-Strength
Class 5: Lower Mid-Strength
Class 6: Mild
Class 7: Least Potent

As a general rule, higher potency topical steroids contain a higher concentration of active steroid and are more likely to cause side effects. However, they may be required to control severe inflammation and flare-ups.

Lower potency steroids are safer for long-term use on larger surface areas. However, they may not provide enough anti-inflammatory effects for acute flare-ups.

Factors Determining Topical Steroid Potency

Several factors determine the potency level of a topical steroid medication, including:

Concentration of active ingredient - Higher concentrations increase potency and visa versa.
Delivery vehicle - Ointments allow deeper penetration than creams and gels.
Addition of penetration enhancers - Ingredients that help the steroid penetrate the skin increase potency.
Use of occlusion - Covering the area with an air/water-tight dressing increases absorption.

The potency level can also vary based on the specific steroid molecule, even when the concentrations are the same. For example, betamethasone dipropionate is more potent than hydrocortisone even at similar concentrations.

Topical Steroid Potency Charts

Topical steroid potency charts rank various steroid products based on their potency. They provide a quick reference to choose an appropriate steroid strength for different affected areas and types of skin conditions.

Some of the most commonly used topical steroid potency charts include:

The Traditional Seven-Class System

This classifies topical steroids into 7 potency classes as follows:

Class 1 - Clobetasol propionate 0.05%
Class 2 - Betamethasone dipropionate 0.05%, Fluocinonide 0.05%
Class 3 - Betamethasone valerate 0.1%, Triamcinolone acetonide 0.5%
Class 4 - Fluocinolone acetonide 0.025%, Hydrocortisone valerate 0.2%
Class 5 - Hydrocortisone 2.5%
Class 6 - Hydrocortisone 1%
Class 7 - Hydrocortisone 0.5%

This system is straightforward but does not account for lower concentrations of potent steroids. The National Psoriasis Foundation and American Academy of Dermatology use this classic 1-7 scale.

The Modified Potency Classification System

This expanded system further divides Class 1 into subclasses 1a (super potent) and 1b (potent) to account for lower concentrations of highly potent steroids. The rest of the classes remain the same.

Class 1a - Clobetasol propionate 0.05%
Class 1b - Betamethasone dipropionate 0.05%, Fluocinonide 0.1%
Class 2 - Betamethasone dipropionate 0.05%, Fluocinonide 0.05%
Class 3 - Betamethasone valerate 0.1%, Triamcinolone acetonide 0.5%
Class 4 - Fluocinolone acetonide 0.025%, Hydrocortisone valerate 0.2%
Class 5 - Hydrocortisone 2.5%
Class 6 - Hydrocortisone 1%
Class 7 - Hydrocortisone 0.5%

This helps select an appropriately strong steroid especially when using lower concentrations of potent drugs.

The Vasoconstriction Assay

This categorizes topical steroids based on their ability to induce vasoconstriction or narrowing of blood vessels as follows:

Group 1 - Most potent vasoconstrictors like clobetasol propionate and betamethasone dipropionate
Group 2 - Intermediate vasoconstrictors like triamcinolone acetonide and fluocinonide
Group 3 - Least potent vasoconstrictors like hydrocortisone

While not used clinically, this assay correlates reasonably with the clinical potency of topical steroids.

Using Topical Steroid Potency Charts

Doctors use topical steroid potency charts for several purposes:

Selecting an appropriate starting topical steroid based on condition severity, affected area, and patient factors.
Determining if a patient needs a higher or lower potency steroid for better control or to reduce side effects.
Comparing two topical steroid products when switching medications.
Limiting the strength/quantity of refills to prevent overuse of potent topicals.

Patients can also use topical steroid potency charts to:

Look up the strength class of a newly prescribed topical steroid
Check if an OTC topical hydrocortisone cream is low, medium or high potency
Compare the relative potencies of two topical steroids they have used before

Factors in Selecting Topical Steroid Potency

When selecting an appropriate topical steroid potency level, doctors consider multiple factors including:

Condition severity - More severe inflammation warrants higher potency.
Affected area - Thinner skin areas like face need lower potency.
Patient age - Lower potency for children.
Area size - Larger areas need lower potency for safety.
Prior steroid use - Chronic use requires periodic downward potency shifts.

Doctors also prefer lower potency steroids for maintenance therapy to minimize adverse effects associated with long-term use.

Using Topical Steroids Safely

When using topical steroids, some safety precautions include:

Avoid using potent steroids on the face, underarms, groin for longer than directed.
Use moderate or low potency steroid on infants and children.
Avoid abrupt high to low steroid switches without medical guidance.
Minimize use on large skin areas unless under medical supervision.
Avoid use under occlusive dressings without medical advice.

It is also important not to exceed the recommended duration of treatment based on potency class to prevent increased side effects.

Conclusion

Topical steroid potency charts are a useful guide for selecting appropriate steroid strength based on condition severity, treatment area, patient factors and safety considerations. When used correctly under medical guidance, topical steroids provide effective and safe treatment for many inflammatory skin conditions.

FAQs

What are the different classes of topical steroid potency?

Topical steroids are ranked from Class 1 (most potent) to Class 7 (least potent). Some charts further divide Class 1 into subclasses 1a and 1b. The classes indicate relative anti-inflammatory strength.

How do doctors decide the right topical steroid strength to prescribe?

Doctors consider the condition severity, affected area, patient age, area size, and prior steroid use to select an appropriate potency level that is effective yet safe.

Is hydrocortisone a mild, moderate or potent topical steroid?

Hydrocortisone is considered a low potency topical steroid, usually belonging to potency Class 6 or 7. Some hydrocortisone creams are available over-the-counter.

Can I use a topical steroid prescribed for one area on another area of my body?

No, topical steroids are prescribed based on the specific area being treated. Using it on another area, especially more sensitive thin-skinned areas, can increase side effects.

Is there a difference between topical steroid ointments, creams and gels?

Ointments allow deeper skin penetration and are more potent. Gels and creams are less potent for use on sensitive areas. Potency also depends on the steroid concentration.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.