Topical calcineurin inhibitors (TCIs) are a group of drugs commonly used to suppress your skin immune system.  These work by inhibiting a chemical in our body known as calcineurin which is responsible for causing inflammation in the skin.  Inflammation means redness or darkening of the skin, itching, swelling and sometimes oozing clear fluid. It is used topically (applied directly to the skin) for a wide range of skin conditions including atopic dermatitis, psoriasis, lichen planus and many others. The products tend to be used in cases when individuals have not been able to sufficiently control their condition with topical steroids and emollients or as steroid-sparing topical treatment so the amount of topical steroids used is reduced.

There are two main types of TCIs used in dermatology: tacrolimus ointment (Protopic 0.03% and 0.1%) and pimecrolimus cream (Elidel).  Dose, duration and other treatment parameters should be discussed and agreed with your doctor however generally they are typically applied twice daily for treatment and twice weekly for prevention of flares (maintenance).

Pros

TCIs don’t cause the known side effects of repeated topical steroid use (skin thinning and changes in skin pigmentation). This makes them useful in patients with disease affecting delicate areas of skin eg eyelids, or individuals with recurrent flares. This also means they are safer for prolonged use for disease maintenance and prevention of relapse. 

Cons

Unlike topical steroids, TCIs take longer to work. They also should be avoided on areas where there is concern about the presence of infection as they can inhibit your skin's ability to defend itself, worsening the infection. 

Calcineurin inhibitors can also increase your sensitivity to sunlight so take the following precautions when commencing treatment:

• Avoid long periods of sun exposure
• Use SPF (at least 30)
• Try and use physical sun blocks such as loose covered clothing and hats

‍

Common side effects of calcineurin inhibitors 

• Itching and burning in areas of application, this tends to improve over time
• Warmth or ‘pins and needles’ in locations where it is applied
• Increased skin redness

‍