Doctors who dress scruffily can be perceived as having a lack of personal hygiene, according to an article in a leading medical journal.
Informal dress among doctors "erodes the image of doctors as responsible and competent", according to an editorial published on bmj.com.
Writing in the journal, consultant microbiologist Stephanie Dancer said that the 2007 decision to rule out ties in the interest of hospital hygiene had led to many junior doctors abandoning formal wear.
Dr Dancer, who works at Hairmyres Hospital in Lanarkshire, wrote: "Doctors are members of a distinguished profession and should dress accordingly.
"Untidiness erodes the image of doctors as responsible and competent.
"Scruffiness is synonymous with being untidy, dishevelled, and unkempt, with having straggly hair, ill fitting clothes, and scuffed shoes - or trainers - as well as not wearing a tie and so on.
"Together these might be taken as a flashing neon sign that says 'I don't care'."
"Scruffiness, however defined, also intimates a lack of personal hygiene and correspondingly lower standards of hygienic behaviour."