Injections using hypodermic needles cause pain, discomfort, localised trauma and apprehension. Additionally, careful use and disposal of needles is required to avoid transmission of blood-borne ...pathogens. As an alternative, microneedles can facilitate drug delivery without significantly impacting on pain receptors or blood vessels that reside beneath the skin outer layers. In this study we aim to determine the pain and sensory response to the application of wet-etch silicon microneedles, when used in such a way as to reliably penetrate skin, and provide a preliminary indication of how skin responds to microneedle injury with time. Twelve subjects received single-blinded insertions of a 25-G hypodermic needle and two microneedle arrays (36 needles of 180 and 280 μm height). The optimal method for microneedle application was determined in a pilot study. Pain intensity was scored using a visual analogue scale (VAS) and sensory perception determined using an adapted McGill Pain Questionnaire Short Form. Skin penetration was determined by external staining and measurement of trans-epidermal water loss (TEWL). Mean VAS scores, verbal descriptions and questionnaire responses showed that the 180 and 280 μm microneedles caused significantly less pain and discomforting sensation in participants than the hypodermic needle. Methylene blue staining and TEWL analysis confirmed that microchannels were formed in the skin following microneedle application. Evidence of microchannel repair and resealing was apparent at 8–24 h post-application. In summary, this study shows that pyramidal wet-etch microneedles can penetrate human skin with minimal pain and sensory discomfort, creating transient pathways for potential drug, vaccine and DNA delivery.
Panniculitis with an unusual diagnosis Owen, E. D.; Logan, R.; May, K. ...
Clinical and experimental dermatology,
March 2020, 2020-Mar, 2020-03-00, 20200301, Letnik:
45, Številka:
2
Journal Article
Recenzirano
Click here for the corresponding questions to this CME article.
Summary
Periorbital and eyelid dermatitis is a recalcitrant and often distressing condition. Allergic contact dermatitis to ophthalmic solutions is an important cause of periorbital and eyelid ...dermatitis. In this review article, we discuss the allergens involved, the difficulties in patch testing, and the recommended concentrations and vehicles for patch testing.
Click here for the corresponding questions to this CME article.
PDF
