Zest Health Guide to Topical Calcineurin Inhibitors (TCIs)

What are Calcineurin Inhibitors (TCIs) and How do They Work?

Topical Calcineurin Inhibitors (TCIs) are prescription creams and ointments used to treat eczema, psoriasis, and other rashes — especially in delicate areas. They work by calming the immune response in your skin.

TCIs can help with itching, redness, dry irritated patches, swelling, and flares in sensitive areas like the face, neck, groin, and skin folds.

TCIs are not steroids. They are safe for delicate areas where steroids can thin the skin. They are often used as a “steroid-sparing” option.

Topical TCIs:

• Protopic (tacrolimus) ointment 
• Elidel (pimecrolimus) cream

Getting Started: Using a TCI Safely

Because TCIs do not contain steroids, they are often prescribed for areas where steroids may not be ideal. Your Zest provider will determine if this treatment is right for you based on:

• Your specific skin condition
• Where your rash is located
• The severity of your symptoms

Your Zest team will customize your care based on your goals and how your skin responds over time.

Applying a TCI

Application Tips:

• Wash your hands before applying the medication
• Apply a thin layer to the affected area only
• Gently rub in until absorbed
• Wash your hands after applying — unless you are treating your hands 
• Use once or twice daily as directed by your provider

How Long Will I Use It?

The length of treatment depends on your symptoms and where the rash is located. Common patterns include:

• During a flare: Use as directed until the skin improves
• Maintenance: Some people use TCIs a few times per week to help prevent future flares

Even if your skin looks better, keep following your provider’s plan. Stopping too early can cause your rash to return. TCIs are designed for safe, long-term use.

How Much Should I Use?

We recommend using the Fingertip Unit (FTU) when you are getting started:

• This is the amount of cream squeezed from the tip of your finger to the first crease.
• 1 FTU covers about the size of the front and back of one adult hand.
• Precision: If you are treating a very small spot, adjust the amount accordingly.

Different body parts need different amounts. If you’re treating a smaller area, adjust the amount accordingly. Your provider can help you get this just right.

Getting Started

• Submit baseline photos of your skin condition for a severity assessment.
• No routine blood work is needed, but please share all current and past medications with your provider.
• Provide previous treatment records, if requested.

Expected Results

• Itching may improve within a few days
• Redness and irritation often improve within 1–2 weeks
• Sensitive areas like face or skin folds, may improve even faster

Is it Safe/Are There Any Side Effects?

TCIs are prescribed regularly by dermatology providers and are considered safe when used as prescribed. They’re especially well-suited for sensitive skin areas including: face, neck, groin and skinfolds where they tend to be gentler than other options.

Most side effects are mild and can include:

• Burning or stinging (especially when first starting)
• Itching
• Increased sensitivity to heat or cold in the treated area
• Photosensitivity (more sensitivity to sunlight)

Less common effects include flu-like symptoms or folliculitis (small red bumps near hair follicles).

A Note on the Black Box Warning:

You might see a warning on your packaging mentioning possible risk of lymphoma or skin cancer. We understand that can feel alarming, and we want to give you the full picture.

• The warning is based on theoretical risk, not proven harm from topical use
• It comes from animal studies using very high doses, and from patients taking oral or injectable immune-suppressing medicines — which are very different from these topical (skin-only) treatments
• Large studies in people using these creams have not shown a clear increase in cancer risk when used as directed.

Storing Your Medication

• Store at room temperature
• Keep tube or bottle tightly closed
• Keep out of reach of children
• Do not ingest medication
• Check expiration date before each use

When to Contact Your Zest Team 

• No improvement after 6 weeks of treatment
• Signs of a severe allergic reaction or infection
• Unusual worsening redness, pain, or swelling, or other signs of skin infection (pus, warmth, fever)
• Any vision changes if using medication near your eyes

Have more questions?

Contact your Zest care team by texting (865)-426-1746 or sending a chat message from your portal. You’ve got this, and we’ve got you. Together, let’s work toward relief and clear skin!