Participant’s average self-reported improvement in erythema was 52% and in skin texture was 53% (Figures 1 and 2). The mean satisfaction score was 6.3 on a scale of 1 to 10 (median 7.5) and 8 out of 10 participants reported they would choose to receive PPx for their KP again in the future. Two patients reported adverse effects. One reported transient hypopigmentation that was resolving and was barely visible at the one month follow-up appointment (Figure 3) and one reported mild purpura in a portion of the treated area that she stated lasted for 2 days after the treatment and was resolved at the one month follow-up. Of the five participants who had previously tried topical emollients or keratolytics for their KP, four stated they thought the PPx had greater efficacy than the topical treatments.
DISCUSSION
PPx is currently approved by the Food and Drug Administration for the treatment of
acne. It is unique among light-based treatments because it combines a pneumatic handpiece that elevates and stretches the skin while concurrently delivering
light from 400-1,200 nm, with a peak absorption at 440-550 nm.11 Its efficacy for acne is believed to be due to the destruction of P. acnes by blue light,
reducing sebum secretion and extruding keratin and sebum out of plugged follicles.11-14 We hypothesized that PPx might also be beneficial in the treatment
of keratosis pilaris when considering the histopathological features. In KP, there is hyperkeratosis, hypogranulosis and follicular plugging in the epidermis
with a mild perivascular lymphohistiocytic infiltrate in the upper dermis and perifollicular regions.3 The combination of the pneumatic component with the
light therapy in PPx would help to alleviate follicular plugging and inflammation seen in KP.
Our results support that skin texture roughness was improved to a greater extent by PPx than the erythema associated with KP by clinical evaluation, but patient self-reports showed an average improvement of slightly greater than 50% in both erythema and skin roughness with just one treatment of PPx.
The mean satisfaction score was 6.3 on a scale of 1 to 10 and a high percentage (80%) of participants stated they would choose this treatment option again in the future. There were no major adverse events in this study such as blistering, scarring or permanent dyspigmentation. One patient had transient hypopigmentation and one had mild purpura. PPx was well
