Efficacy of Aprepitant for Refractory Pruritus in Patients With Epidermolysis Bullosa and Atopic Dermatitis: A Retrospective Study

Pruritus is a significant component of dermatologic conditions including epidermolysis bullosa (EB) and atopic dermatitis (AD) that can be difficult to medically manage and is detrimental to quality of life (QOL). Aprepitant, a substance P/neurokinin-1 antagonist typically used as an antiemetic after chemotherapy or surgery, is presented as an emerging potential agent in the treatment of pruritus. This study aimed to assess the efficacy of aprepitant for the control of refractory pruritus in patients with EB and AD.This study included 37 patients with a diagnosis of either EB (24 patients) or AD (13 patients) aged 10 months to 37 years. Exclusion criteria included insufficient medical record documentation, inability to access the medication, or nonadherence to aprepitant.A single-center retrospective medical record review was conducted in all patients with a diagnosis of either EB or AD, treated for pruritus with aprepitant. Participants or parents/legal guardians were sent a questionnaire to assess the use and efficacy of aprepitant; metrics included length of effect, reduction in adjunctive medication use, percentage of itch reduction, and impact on QOL. Aprepitant was prescribed according to standard dosing for chemotherapy-induced nausea/vomiting, enterally 3 mg/kg up to 125 mg (day 1), and 2 mg/kg up to 80 mg (day 2, 3), with frequency ranging from monthly to biweekly.Data from a total of 37 patients with EB and AD were reviewed; there were 17 female patients. Twenty-six patients were excluded (10 with EB and 16 with AD) due to insufficient documentation or inability to receive the medication (either insurance denial or high cost). In patients with EB, 58% reported improvement in pruritus with the use of aprepitant, with increasing efficacy seen in older ages; it was ineffective in patients with EB younger than 2 years. In patients with AD, 85% of patients noted improvement in pruritus regardless of age (there were no patients younger than 2 years in the AD group). A total of 13 patients completed the survey; 9 patients continued taking the medication, whereas 4 patients with EB stopped after a range of 3 to 9 months. Adverse effects were noted in 8% of patients, including paradoxical increase in pruritus, appetite suppression, and insomnia. Common concerns cited for cessation of the treatment included ineffectiveness, insurance coverage, and medication nonavailability.In a small cohort of patients with EB and AD, aprepitant was effective in the reduction of refractory pruritus in approximately half of patients with EB and the majority of patients with AD with a favorable adverse effect profile.Limitations in this retrospective review include a single-center cohort with a small number of participants and low survey response. Additionally, the nature of the retrospective study and questionnaire-based design limit its generalizability. This drug may represent an option for patients with AD and EB who remain itchy despite the use of current commonly prescribed antihistamines with an overall favorable adverse effect profile. However, the study of this drug prospectively is warranted, as is the need for the medication to be more widely and easily accessible.