Managing chronic skin conditions like eczema, also known as atopic dermatitis, often involves the use of topical medications to control inflammation and discomfort. Patients frequently have questions about their prescribed treatments, particularly concerning whether a new medication falls into the category of “steroids” due to common awareness of potential side effects associated with steroid use.
What is Tacrolimus Ointment?
Tacrolimus ointment, often recognized by the brand name Protopic, is not a steroid. It is classified as a topical calcineurin inhibitor (TCI), representing a distinct class of non-steroidal medications. This ointment is specifically prescribed for the treatment of moderate to severe atopic dermatitis in adults and children, typically those aged two years and older. Tacrolimus ointment works by modulating the immune response within the skin to reduce inflammation and symptoms of eczema.
How Tacrolimus Works
Tacrolimus ointment reduces inflammation through a specific mechanism that differs from corticosteroids. It acts by inhibiting calcineurin, a protein found inside immune cells, particularly T-cells, within the skin. This inhibition prevents the activation of these T-cells and, consequently, the release of inflammatory substances known as cytokines. Cytokines are signaling molecules that contribute to the redness, itching, and swelling characteristic of eczema, so by blocking their production, tacrolimus helps to alleviate these symptoms.
The binding of tacrolimus to an intracellular protein called FKBP-12 forms a complex that then inhibits the phosphatase activity of calcineurin. This inhibition prevents a process called dephosphorylation, which is normally required for a nuclear factor known as NFAT (nuclear factor of activated T-cells) to enter the nucleus. By keeping NFAT out of the nucleus, tacrolimus stops the initiation of gene transcription for pro-inflammatory cytokines like interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ), thereby calming the immune response in the skin.
Key Differences from Steroid Creams
Tacrolimus ointment offers several advantages over topical corticosteroids. Tacrolimus does not typically cause common steroid-related side effects such as skin thinning (atrophy), the development of stretch marks (striae), or changes in skin pigmentation. A 2023 study found that tacrolimus ointment did not cause skin atrophy compared to hydrocortisone cream.
This distinct side effect profile makes tacrolimus ointment suitable for long-term management of eczema without the cumulative risks associated with prolonged steroid use. It can be safely applied to sensitive areas of the body, including the face, eyelids, neck, and skin folds. These areas are often more susceptible to the adverse effects of topical steroids due to higher absorption rates and skin delicacy.
Tacrolimus has its own unique considerations. Patients may experience initial side effects like burning or itching at the application site, which usually subside within the first few days to a week of treatment. There is also a theoretical concern regarding an increased risk of skin infections and sun sensitivity. The FDA has placed a “black box warning” on tacrolimus ointment concerning a theoretical risk of skin cancer and lymphoma, though studies have not definitively confirmed a causal link, and the overall risk is considered very low.
Using Tacrolimus Ointment Safely
To use tacrolimus ointment effectively and safely, apply a thin layer only to the affected areas of the skin, typically twice a day. It is important to gently rub the ointment into the skin completely.
Patients should avoid excessive sun exposure, including tanning beds and UV light therapy, while using tacrolimus ointment, and wear protective clothing when outdoors. The ointment should not be applied to skin that is infected unless the infection has been addressed. Additionally, consuming alcohol while using tacrolimus can cause skin flushing or redness in the treated areas. Always follow the specific instructions provided by your healthcare professional and consult them if any concerns or severe side effects arise.