Adherence to Topical Treatment Can Improve Treatment-Resistant Moderate Psoriasis
Most patients with psoriasis have limited disease that should be manageable with topical treatment. However, psoriasis often is resistant to topical treatment. The aim of our study was to determine if patients using psoriasis-resistant topical treatments can be effectively treated with topicals under conditions promoting adherence. During this open-label, randomized, single-center clinical study, 12 patients with moderate psoriasis that previously failed topical treatment were selected and treated with desoximetasone spray 0.25% for 2 weeks. Six patients were randomized to receive twice-daily telephone call reminders to further encourage good adherence. Disease severity was assessed by the visual analog scale for pruritus, psoriasis area and severity index (PASI), total lesion severity score (TLSS), and investigator global assessment (IGA). At the end of the study, most patients improved in most scores. Therefore, apparent resistance to topical treatment often is due to poor adherence and can be overcome, at least over the short term.
Practice Points
- Most patients with psoriasis are good candidates for topical treatment.
- Topical treatment of psoriasis often is ineffective.
- Topical treatment of psoriasis can be rapidly effective, even in patients who reported disease that was resistant to topical treatment.
The percentage reduction in pruritus ranged from 66.7% to 100% and 50.0% to 85.7% with and without telephone call reminders, respectively. Improvement in PASI ranged from 18.0% to 62.8% and 0% to 54.5% with and without telephone call reminders, respectively. Improvement in TLSS and IGA was of lower magnitude but showed a similar pattern, with numerically greater improvement in the telephone call reminders group compared to the group that was not called (eTable 2). No patients showed a worse score for pruritus on the visual analog scale, PASI, TLSS, or IGA.
Discussion
Topical corticosteroids are highly effective for psoriasis in clinical trials, with clearance in 2 to 4 weeks in 60% to 80% of patients, a rapidity of response not matched by even the most potent biologic treatments.8,9 However, topical corticosteroids are not always effective in clinical practice. There may be primary inefficacy (they do not work at first) or secondary inefficacy (a previously effective treatment loses efficacy over time).10 Poor adherence can explain both phenomena. Primary adherence occurs when patients fill their prescription; secondary adherence occurs when patients follow the medication recommendations.11 Primary nonadherence is common in patients with psoriasis; in one study, 50% of psoriasis prescriptions were not filled.12 Secondary adherence also is poor and declines over time; electronic monitoring revealed adherence to topical treatments in psoriasis patients decreased from 85% initially to 51% at the end of 8 weeks.7 Given the high efficacy of topical corticosteroids in clinical trials and the poor adherence to topical treatment in patients with psoriasis, we anticipated that psoriasis that is resistant to topical corticosteroids would improve rapidly under conditions designed to promote adherence.
As expected, disease improved in almost every patient in this small cohort when they were given a potent topical corticosteroid, even though they previously reported that their psoriasis was resistant to potent topical corticosteroids. Although this study enrolled only a small cohort, it appears that the majority of patients with limited psoriasis that was reported to be resistant to topical treatment can see a response to topical treatment under conditions designed to encourage good adherence.
,We believe that the good outcomes seen in our study were a result of good adherence. Although the desoximetasone spray 0.25% used in this study is a superpotent topical corticosteroid,8 the response to treatment was unlikely due to changing corticosteroid potency because 10 of 12 patients had tried another superpotent topical corticosteroid (clobetasol) and it failed. We chose a spray product for this study rather than an ointment to promote adherence; however, this choice limited the ability to assess adherence directly, as adherence-monitoring devices for spray delivery systems are not readily available.
Our study was limited by the small sample size and brief duration of treatment. However, the effect size is so large (ie, the topical treatment was so effective) that only a small sample size and brief treatment duration were needed to show that a high percentage of patients with psoriasis that had previously failed treatment with topical corticosteroids can in fact respond to this treatment.
We used telephone calls as reminders in 50% of patients to further encourage adherence. The study was not designed or powered to assess the effect of the telephone call reminders, but patients receiving those calls appeared to have slightly greater reduction in disease severity. Nonetheless, twice-daily telephone call reminders are unlikely to be a wanted or practical intervention; other approaches to encourage adherence are needed.
Frequent follow-up visits were incorporated in our study design to maximize adherence. Although it might not be feasible for clinical practices to schedule follow-up visits as often as in our study, other approaches such as virtual visits and electronic interaction might provide a practical alternative. Multifaceted approaches to increasing adherence include encouraging patients to participate in the treatment plan, prescribing therapy consistent with a patient’s preferred vehicle, and extensive patient education.13 If patients do not respond as expected, poor adherence can be considered. Other potential causes of poor outcomes include error in diagnosis; resistance to the prescribed treatment; concomitant infection; irritant exposure; and, in the case of biologics, antidrug antibody formation.14,15
