The study presented at the British Association of Dermatologists' conference in Manchester last week found that health centres which used the guidelines made twice as many appropriate referrals as those not using them.
The trial compared the appropriateness of psoriasis referrals from 82 health centres using referral guidelines developed by consultant dermatologists, with 83 centres not given the guidelines.
The GP practices in the intervention group were also offered a practice-based nurse-led training session.
However, just 25 GP practices took up this offer.
An independent committee that contained a dermatology specialist nurse, a consultant dermatologist and a GP looked at the quality of referrals to secondary care.
They concluded that 2.47 times as many people were referred appropriately by practices using the guidelines as by practices not using them.
Dr Stephen Hayes, a GPSI in dermatology and member of the Primary Care Dermatology Society committee, said: 'This trial is welcome. Much is being done on exciting therapies for psoriasis, but this looks at a low-level and inexpensive educational intervention.
'Patients may suffer from being referred with the wrong level of priority or without basic treatments being tried first.'
He added that similar guidelines with practice-based training sessions would probably improve recognition of and treatment for a range of dermatological problems, including skin cancer.
British Journal of Dermatology 2006: 155 (Suppl.1) 1-9