Single application of a fluorescent test cream by healthy volunteers: assessment of treated and neglected body sites

Abstract

Management of dermatological self-treatment is demanding. Imperfect application of creams and ointments and poor adherence to topical treatment are common, resulting in unsatisfactory treatment outcome. To assess the technique and precision of test subjects' self-application of a test cream. Treated and neglected skin sites were measured after intended widespread single application of a fluorescent test cream. Twenty healthy volunteers (10 women, 10 men) were included. They were asked to treat their whole skin surface with the fluorescent test cream, except the head and neck and skin covered by underwear. Treated and untreated sites were subsequently measured under Wood's ultraviolet radiation. Thirty-one per cent of the skin surface that was a target for application did not show any fluorescence and thus was assumed to have been untreated. Typical neglected sites included the central back, the upper breast, the axilla with surrounding skin, the legs and the feet, particularly the sole. The posterior aspect of both trunk and extremities, not easily inspected, was more often neglected. In the treated sites the fluorescence was typically uneven. Qualified and motivated persons with no obvious physical limitations practised imperfect self-application of a test cream mimicking a therapeutic cream product. As much as 31% of the skin surface was neglected. Sites especially prone to nonapplication were identified. This might imply that dermatological patients on long-term self-treatment may practise local application very poorly, a problem of major therapeutic and economic importance. A fluorescent test cream can be used for research, and as an educational tool in the training of dermatological patients on how to apply local treatment.