Durometry as an alternative tool to the modified Rodnans skin score in the assessment of diffuse systemic sclerosis patients: a cross-sectional study

Abstract Background The reproducibility and reliability of the modified Rodnan's Skin Score (mRSS) are debated due to investigator-related subjectivity. Here, we evaluate if durometry correlates with mRSS in patients with diffuse systemic sclerosis (SSc). Methods This cross-sectional study was conducted from December 2018 to June 2019, including 58 diffuse SSc patients. Two certified researchers, blind to each other's scores, performed the mRSS, followed by durometry at 17 predefined skin sites. For durometry and mRSS, individual scores per skin site were registered. Durometry and mRSS results measured by each researcher, as well as scores from different researchers, were compared. Skin thickness measurements from forearm skin biopsies were available in a subset of the patients, for comparisons. Statistical analyses included Cohen's Kappa Coefficient, Intraclass Correlation Coefficient, Kendall's Coefficient and Spearman's test. Results Mean (standard deviation, SD) patient age was 44.8 (12.9) years, and 88% were female. Inter-rater agreement varied from 0.88 to 0.99 (Intraclass correlation coefficient) for durometry, and 0.54 to 0.79 (Cohen's Kappa coefficient) for mRSS, according to the specific evaluated sites. When data were compared with skin thickness assessed in forearm biopsies, durometry correlated better with skin thickness than mRSS. Conclusion Durometry may be considered as an alternative method to quantify skin involvement in patients with diffuse SSc. The strong inter-rater agreement suggests that the method may be useful for the assessment of patients by multiple researchers, as in clinical trials.(AU)

Tester to Measure the Hardness of the Nasal Tip: A New Device

The nasal tip occupies important position in Asian rhinoplasty because Asian has a nasal tip featuring of round or bulbous shape, lower height and wider base compared with that of Caucasian. The hardness of the nasal tip may be increased during the course of a routine rhinoplasty by maneuvers such as incision or excision of the lower lateral cartilage, suturing, and grafting of the cartilages. Changes of the hardness may be a component of postoperative dissatisfaction. However there is no device to measure the hardness of the nasal tip. We developed a "nasal tip durometer" using Teclock Durometer GS series 701 G. The spring rate of Teclock Durometer was converted from 0.223 kgf/mm to 0.036 kgf/mm to apply to the human body. After the remote air switch was fixed to apply with the same speed in a patient's nose, we manufactured the frame attachable to the surgical operation table. The reliability, validity, and responsiveness to clinical change of our durometer were evaluated in a clinical study of 20 patients. Our durometer was highly reliable (Spearman correlation coefficient, r=0.95), valid (Spearman correlation coefficient, r= 0.85), and responsible (effect size=11.37). We concluded that nasal tip durometer was useful to measure the hardness of the nasal tip objectively.

Measurement of Skin Hardness with Durometer in Normal Korean Individuals / 대한피부과학회지

BACKGROUND: The measurement of the hardness of a skin lesion is an important component of cutaneous examination in evaluating the progression of diseases such as scleroderma. Current methods to assess hardness have not gained wide acceptance because they tend to be cumbersome, time consuming, and costly. OBJECTIVE: The purpose of this study was to obtain the normal range of skin hardness according to anatomical sites, age groups and sex, and to show the differences among them. METHODS: Ten different anatomical locations of 123 normal Korean individuals (61 males and 62 females) were measured with a durometer. RESULTS: 1. Skin hardness between the two sexes showed significant difference in extensor upper arm, extensor forearm, back, posterior thigh and calf. Excluding the extensor upper arm, male skin was generally harder than female. Shin and calf were significantly harder and flexor upper arm and abdomen were significantly softer than other areas. 2. The tendency of the hardness was similar in each age group. Shin was significantly harder than all other areas in 11-20, 21-30, and 51-60 age groups. Although flexor upper arm and abdomen showed statistically significant softness in 51-60 and >60 age groups, they tended to be softer than other areas in all age groups. 3. Although statistical significance was not seen among all the age groups, age group <11 tended to be harder than other age groups in flexor upper arm, extensor upper arm, flexor forearm and abdomen. CONCLUSION: Skin hardness measured with a durometer showed variation according to sex, age and location. The durometer is an effective, reliable and easy tool especially for the follow-up of the changes in skin hardness in an individual.