This is a prospective validation study aiming to develop and validate a standardised IGA
score for KP. Firstly, a preliminary score will be developed using deidentified photos of
patients with KP. These photos will only be used to create the training slide for the
assessors. The proposed score, Keratosis Pilaris Area Index (KPAI), is a 5-point IGA score
(0-4) of five main body areas: face, upper limbs, lower limbs, trunk, and buttocks, for a
maximum of 20 in two main categories, activity (erythema, skin roughness and papulation) and
damage (pigmentation and scarring). The final score will be a maximum of 100. This will be
compared to a standard 0-4 IGA score, defined specifically for KP, known as a KP-IGA.
The one-day scoring exercise has been modified from the Epidermolysis Bullosa Disease
Activity and Scarring Index (EBDASI) validation (Loh et al., 2014). It will take place at
Premier Specialists, Kogarah, Sydney with all co-investigators conducting the study in person
at this single study site. Each dermatologist and medical professional involved will receive
training on using the scores through a slideshow of training photos prior to the live scoring
session. Five dermatologists and four medical professionals will be randomly assigned to
assess 20 KP patients in 5-minute intervals, using the proposed scoring system, KPAI, and the
KP-IGA score. This data will be used to assess inter-rater reliability.
Each dermatologist or medical professional will be randomly assigned to rescore two patients
after seeing other patients to minimise recall bias. The randomisation will be done by an
investigator who is uninvolved in the scoring session and has had no interaction with both
patients and assessors. Data gathered from this section is used to determine intra-rater
reliability.
Every participant will also complete two QOL questionnaires: the DLQI/CDLQI and HADS. This
data will be used to provide insight of patient's subjective perceptions of KP and the
psychological impact it may have on them.
Participants who attended the scoring day will be invited to attend a follow-up scoring
session in September - October 2022. The purpose of this scoring session is to see how stable
their condition is and take baseline photographs of their skin to monitor their condition.
Four assessors will score the participants in 5-minute intervals with the proposed scoring
system KPAI and the KP-IGA. Participants will be offered free samples of Cerave Salicylic
Acid Smoothing Cleanser and Cream to try. They will be invited to return for another
rescoring in November - December 2022 to see if there is any improvement in their KP and if
the score is responsive to change.
In the November - December 2022 scoring session, participants will be given free samples of
Propaira 30% Urea exfoliating emollient and Propaira 20% Lactic acid exfoliating lotion to
try. They will be invited to return for a fourth scoring session in December to monitor their
progress and see if the scores improve.