Abstract It is well established that dermatology is poorly understood among medical students and doctors of all grades. The combination of time allocated to teaching of dermatology, as well as the high impact of the hidden curriculum reinforcing dermatology as difficult and mysterious, lends itself to perpetuation of the zeitgeist. Cutaneous infections have a particularly high cognitive load due to their relatively short presentation time and wide varieties of manifestations. Investigation of cutaneous infections is also problematic with incorrect sampling undertaken for different infections. Junior doctors frequently default to black charcoal swabs for all skin infections, often getting feedback as inappropriate investigation after the patient has been discharged or are being read by different doctors altogether due to shift working. For 8 years, we have been running a practical tutorial session on skin infections at Swansea University Medical School. Old venesection prosthetic arms are decorated with simulation bacterial, fungal and viral infections. The bacterial pus is cold custard (or ‘pustard’) on swollen reddened sections. Herpetic vesicles are simulated with bubble wrap injected with Hibiscrub®. Tinea is simulated by dry polyvinyl acetate glue surrounded by red marker. The students have access to black charcoal swabs, red viral swabs, scalpels and fungal scraping cards. They also have dry universal containers and investigation forms. The 10–12 year-2 students are tasked with diagnosing each infective presentation with a short history and medical photography to back up the prosthetic representation. They then have to select the most appropriate investigative method and information to give to the microbiology department. Some students only have access to black charcoal swabs and need to improvise working out how to use the universal containers for their investigations. The knowledge is then shared at the end of the 40-min tutorial. This is conducted a day before the skin infection lecture, to reduce the cognitive load of that lecture. There has been consistently good feedback for this session, which allows students to think in real time about common clinical scenarios, making best use of laboratory services and improvising investigative techniques, where appropriate resources may not be available. The prosthetics have worked well year on year. Many of our first students are now practising doctors locally, and their dermatology knowledge is manifest in referrals. By practising the techniques in simulation, they are comfortable doing so in working life.