SUMMARY
Eighty‐three participants with psoriasis were followed over a 2‐year period assessing the severity, morbidity and cost of their disease over time. At recruitment, they were examined by a dermatologist who classified them on a global basis as mild (47%), moderate (35%) or severe (18%). A Psoriasis Area and Severity Index (PASI) score was also recorded at the initial interview. Participants completed questionnaires on the morbidity related to having psoriasis using the Psoriasis Disability Index (PDI) and a self‐administered PASI (SAPASI) score at the initial interview and at 3‐monthly intervals over the 2‐year period. During the 3‐monthly follow ups, patients also collected information on the cost of treatment. Using the PDI data, two‐thirds of the respondents said that, as a result of their psoriasis, they altered the way they carried out their normal daily activities; more than 50% wore different types or colours of clothing; more than 50% said their home was made more messy or untidy; and over a third had problems at the hairdresser or difficulties playing sport. The annual out‐of‐pocket expense for medical products was around AUD$250 per person, with costs ranging from zero to more than AUD$2000 per individual over the 2‐year period. Costs were highest for over‐the‐counter products purchased without a medical prescription. There were similar variations in the out‐of‐pocket expenses of medical consultations depending on the level of medical care required. The study revealed that the standard methods used for classification of severity of psoriasis, such as the PASI or SAPASI scores, do not take into account the treatment being used at the time the score is recorded and therefore may not accurately reflect the true severity.