Abstracts Category : Other

"I don't want to manage it, I want to get rid of it" : a narrative analysis of living with chronic plaque psoriasis, and an investigation into vitamin D as a treatment

by Michelle Anne Ingram

As a chronic skin disease, plaque psoriasis can cause significant psychosocial, emotional andphysical burden. Psoriasis sufferers perceive others as lacking understanding around what it islike to live with this condition, and there has been little research exploring the experience ofpsoriasis in depth. The burden of psoriasis can be compounded by the difficulty of treating it,and the inconveniences, side effects and risks of available treatments, suggesting the importanceof finding a safe, effective and convenient treatment for psoriasis. Vitamin D and psoriasishave a long-standing relationship, with topical vitamin D analogues used to treat mild-tomoderatedisease, and observational studies suggesting an association between higher systemicvitamin D (serum calcidiol) concentrations and less severe psoriasis. These findings suggestvitamin D3 supplements, which raise serum calcidiol concentrations, might improve psoriasis.In this thesis, two studies were conducted to address the limited in-depth understanding of theexperience of psoriasis, and the need for a safe, effective treatment, respectively. The aimswere 1) to gain a deeper understanding of the experience of living with psoriasis; and 2) toinvestigate whether oral vitamin D3 supplements can effectively treat psoriasis.For 1), data from semi-structured interviews with 10 men and women with psoriasis wasanalysed using narrative analysis. Narrative trajectories involving three predominant narrativeforms shaped participants stories: restitution, where the focus was on overcoming psoriasisthrough trying to find an effective treatment or cure; chaos, where psoriasis was experienced asoverwhelming and brought about a sense of hopelessness, and resignation, which was centredon begrudgingly accepting psoriasis in order to be able to get on with life. Participants haddifferent narrative trajectories and shifted between forms over time, with the nature ofexperience linked with the relative stability and severity of a persons psoriasis and their beliefsabout their ability to manage it.For 2), a randomised, double-blinded, placebo-controlled trial was conducted with 101participants 18 years allocated to 100,000 International Units (IU) vitamin D3/month (n = 67)for 12 months (200,000 IU at baseline), or an identical placebo (n = 34). Psoriasis severity(Psoriasis Area and Severity Index [PASI]) and serum calcidiol concentrations were assessed at3-monthly intervals. The primary outcome was the difference in PASI between treatment andplacebo over time, assessed using a linear mixed model. Psoriasis severity did not differbetween groups at any time (group F(1, 106) = 0.59, p = 0.44, group*time F(4, 370) = 0.52, p =0.72). Yet these findings are inconclusive, as serum calcidiol significantly increased frombaseline in both the treatment and the placebo group, and a mild improvement in PASI scorefrom baseline also occurred in each group. A non-predetermined secondary analysis wasperformed by assessing the strength