<qa>  What is the name of the calcineurin inhibitors tacrolimus and piPatients with Netherton syndrome, a rare genodermatosis, manifest a chronic, eczematous dermatitis with erythema and scaling that is often recalcitrant to conventional therapy with emollients and topical corticosteroids. These patients display an altered epidermal barrier with increased permeability to topical agents and are therefore susceptible to evaporative transepidermal water loss and infection. Topical therapy with the calcineurin inhibitors tacrolimus and pimecrolimus has been demonstrated to improve the skin integrity and the quality of life of patients with several chronic dermatoses, including atopic dermatitis. As a result of the underlying skin barrier dysfunction, however, the possibility of significant systemic absorption and resultant side effects is a concern when these agents are used in patients with Netherton syndrome. Experience with topical tacrolimus 0.1 ointment for patients with Netherton syndrome has demonstrated both marked efficacy as well as significant systemic absorption of the drug in this patient population. Use of topical pimecrolimus in patients with Netherton syndrome has not been reported to date. Investigation of the extent of systemic absorption and side effects will help to define the safety and efficacy profile of topical pimecrolimus in patients with Netherton syndrome. 