Epidemiology of skin event rates among users of pumps for the subcutaneous administration of drugs for chronic conditions

To provide the epidemiology of skin events occurring during long-term administration of medications delivered by continuous subcutaneous infusion pump (CSIP) systems as background rates for the development of novel CSIP treatments to use in community-based settings.Using a United Kingdom general practice database, we conducted a study to assess the rates of skin events among new users of apomorphine and insulin delivered by CSIP in patients with Parkinson's disease or diabetes, respectively. Skin events included skin infections, skin nodules/localized swelling, dermatitis/eczema, urticaria/erythema, and rash/other non-specific skin eruptions.Five hundred and fifty-seven adults (age 30+) were included in this descriptive cohort. The median duration of CSIP use was 17 months among 255 apomorphine users and 41 months among 302 insulin users. By 60 months, ∼40% of both cohorts experienced skin events. Repeated skin events occurred in 11% of the apomorphine cohort and 14% of the insulin cohort at any time during follow-up. The overall skin event rate in the apomorphine cohort was 17 per 1000 person-months (PM) and 13 per 1000 PM in the insulin cohort. The most common skin events in both cohorts were infection and rash/unspecified skin eruptions. The highest rates of skin events occurred soon after apomorphine CSIP initiation (36 per 1000 PM in weeks 1-2 and 50 per 1000 PM in weeks 3-4), with lower rates after 4 weeks. Insulin CSIP users' skin event rates were consistent over the treatment duration.Clinically important skin events are common during long-term administration of medications by CSIP.