Effectiveness and Safety of Phototherapy
Our secondary aim was to examine the effectiveness and safety of phototherapy in older adults. Phototherapy was effective in this population, with 50 of 52 patients (96%) achieving a high or medium level of clearance. The degree of clearance for each of the dermatologic conditions is shown in Figure 2. Psoriasis and dermatitis achieved high clearance rates in 81% (21/26) and 82% (9/11) of patients, respectively. Overall, conditions did not have significant differences in clearances rates (Fisher exact test, P=.10). On average, it took patients 33 treatments to achieve medium or high rates of clearance. Psoriasis cleared more quickly, with an average of 30.4 treatments vs 36.1 treatments for other conditions, but the difference was not significant (t test, P=.26). Patients received an average of 98 total phototherapy treatments; the median number of treatments was 81 due to many being on maintenance therapy over several months. There was no relationship between a history of treatment with phototherapy and the total number of treatments needed to achieve clearance (t test, P=.40), but interestingly, those who had a history of phototherapy took approximately 5 more treatments to achieve clearance. The present study found that a slightly larger number of men were being treated for psoriasis (15 men vs 11 women), but there was no significant difference in response rate based on gender.
Figure 2. Degree of clearance by dermatologic condition.
Side effects from phototherapy were minimal; 24 patients (46%) experienced grade 1 (mild) erythema at some point during their treatment course. Thirteen (25%) patients experienced grade 2 erythema, but this was a rare event for most patients. Only 1 (2%) patient experienced grade 3 erythema 1 time. Three patients experienced increased itching (6%). Thirteen (25%) patients had no side effects. None developed severe erythema or blisters, and none discontinued phototherapy because of side effects. Over the course of the study year, we found a high degree of acceptance of phototherapy treatments by older patients: 22 (42%) completed therapy after achieving clearance, 10 (19%) were continuing ongoing treatments (maintenance), and 15 (29%) stopped because of life circumstances (eg, other health issues, moving out of the area). Only 4 (8%) stopped because of a lack of effectiveness, and 1 (2%) patient because the treatments were burdensome.
Comparison of Outcomes
Our third aim was to compare the outcomes with similar studies in the United Kingdom16 and Turkey.17 This study confirmed that phototherapy is being used in older adults (22.7% of this study’s total patients) and is an effective treatment for older patients experiencing a range of challenging inflammatory and proliferative skin diseases similar to studies in the general population. Prior phototherapy studies in elderly patients also found psoriasis to be the most common skin condition treated, with 1 study finding that 51% (19/37) of older phototherapy patients had psoriasis,16 while another reported 58% (37/95) of older phototherapy patients had psoriasis.17 These numbers are similar to those in our study, which showed 50% (26/52) of elderly phototherapy patients had psoriasis. Psoriasis is the main indication for treatment with NB-UVB phototherapy in the general population,19 and because the risk for psoriasis increases with age,20 it is not surprising that all 3 studies found psoriasis to be the most common indication in elderly phototherapy patients. Table 3 provides further details on conditions treated in all 3 studies.
Comment
Our study found that 94% of patients with psoriasis achieved clearance with an average of 30.4 treatments, which is comparable to the reported 91% response rate with an average of 30 treatments in the United Kingdom.16 The other similar study in Turkey17 reported 73.7% of psoriasis patients achieved a 75% or more improvement from baseline with an average of 42 treatments, which may reflect underlying differences in regional skin type. Of note, the scatter chart (Figure 3) shows that several patients in the present study’s analysis are listed as not clear, but many of those patients had low treatment numbers below the mean time to clearance. Thus, the present study’s response rate may have been underestimated.
Figure 3. Comparison of total treatments and side effects across all conditions. MF indicates mycosis fungoides; DNC, did not clear. Bold rule indicates patients who experienced side effects greater than grade 1.
In the general population, studies show that psoriasis treated with standardized phototherapy protocols typically clears with an average of 20.6 treatments.21 The levels of clearance were similar in our study’s older population, but more treatments were required to achieve those results, with an average of 10 more treatments needed (an additional 3.3 weeks). Similar results were found in this sample for dermatitis and mycosis fungoides, indicating comparable clearance rates and levels but a need for more treatments to achieve similar results compared to the general population.
Additionally, in the current study more patients experienced grade 1 (mild) erythema (46%) and grade 2 erythema (25%) at some point in their treatment compared with the United Kingdom16 (1.89%) and Turkey17 (35%) studies, though these side effects did not impact the clearance rate. Interestingly, the current study’s scatter chart (Figure 3) illustrates that this side effect did not seem to increase with aging in this population. If anything, the erythema response was more prevalent in the median or younger patients in the sample. Erythema may have been due to the frequent use of photosensitizing medications in older adults in the United States, some of which typically get discontinued in patients 75 years and older (eg, statins). Other potential causes might include the use of phototype vs minimal erythema dose–driven protocols, the standard utilization of protocols originally designed for psoriasis vs other condition-specific protocols, missed treatments leading to increased sensitivity, or possibly shielding mishaps (eg, not wearing a prescribed face shield). Given the number of potential causes and the possibility of overlapping factors, careful analysis is important. With NB-UVB phototherapy, near-erythemogenic doses are optimal to achieve effective treatments, but this delicate balance may be more problematic for older adults. Future studies are needed to fully determine the factors at play for this population. In the interim, it is important for phototherapy-trained nurses to consider this risk carefully in the older population. They must follow the prescribed protocols that guide them to query patients about their responses to the prior treatment (eg, erythema, tenderness, itching), photosensitizing medications, missed treatments, and placement of shielding, and then adjust the treatment dosing accordingly.
Limitations
This study had several limitations. Although clinical outcomes were recorded prospectively, the analysis was retrospective, unblinded, and not placebo controlled. It was conducted in a single organization (Group Health [now Kaiser Permanente Washington]) but did analyze data from 4 medical centers in different cities with diverse demographics and a variety of nursing staff providing the treatments. Although the vitiligo treatment protocol likely slowed the response rate for those patients with vitiligo, the numbers were small (ie, only 3 of 52 patients), so the researchers chose to include them in the current study. The sample population was relatively small, but when these data are evaluated alongside the studies in the United Kingdom16 and Turkey,17 they show a consistent picture illustrating the effectiveness and safety of phototherapy in the older population. Further epidemiologic studies could be helpful to further describe the usefulness of this modality compared with other treatments for a variety of dermatoses in this age group. Supplementary analysis specifically examining the relationship between the number and type of photosensitizing medications, frequency of erythema, and time to clearance also could be useful.
Conclusion
Older adults with a variety of dermatoses respond well to phototherapy and should have the opportunity to use it, particularly considering the potential for increased complications and costs from other treatment modalities, such as commonly used immunosuppressive pharmaceuticals. However, the current study and the comparison studies indicate that it is important to carefully consider the slower clearance rates and the potential risk for increased erythema in this population and adjust patient education and treatment dosing accordingly.
Unfortunately, many dermatology centers do not offer phototherapy because of infrastructure limitations such as space and specially trained nursing staff. Increasing accessibility of phototherapy for older adults through home treatments may be an alternative, given its effectiveness in the general population.22,23 In addition, home phototherapy may be worth pursuing for the older population considering the challenges they may face with transportation to the clinic setting and their increased risk for serious illness if exposed to infections such as COVID-19. The COVID-19 pandemic has brought to light the need for reliable, safe, and effective treatments that can be utilized in the safety of patients’ homes and should therefore be considered as an option for older adults. Issues such as mobility and cognitive decline could pose some complicating factors, but with the help of a well-trained family member or caregiver, home phototherapy could be a viable option that improves accessibility for older patients. Future research opportunities include further examination of the slower but ultimately equivalent response to phototherapy in the older population, the influence of photosensitizing medications on phototherapy effects, and the impact of phototherapy on utilization of immunosuppressive pharmaceuticals in older adults.