Chronic Nail Biting in Youth

Nail Melatonin Content: A Suitable Non-Invasive Marker of Melatonin Production

Melatonin plays multiple physiological roles in the human body. Evaluation of melatonin production by the determination of urinary 6-sulfatoxymelatonin in 24-h samples has important drawbacks which hinder the successful evaluation of melatonin production in large cohorts. Here, we evaluated the potential of nail analysis for estimating melatonin production. Firstly, mass spectrometry methodology for the determination of melatonin in nails was optimized and successfully validated. The method was found to be linear in the range 6.5-830 fg/mg with intraday and interday accuracy in the range 100-104 %, precision below 15 % and a LOD of 3.5 fg/mg. Secondly, nail melatonin concentrations from 84 volunteers (age 5-96) were determined. The expected correlation between melatonin and age was obtained (correlation coefficient -0.615; p < 0.001). Additionally, we showed that fingernails are preferable to toenails to determine nail melatonin content. Finally, fingernails collected for 180 days after melatonin administration (two volunteers, 1.9 mg/night during 5 days) were analyzed. Nail melatonin concentrations immediately rose after administration and went back to pre-administration values after ≈100 days in both volunteers. Our results suggest that melatonin determination in nails is a suitable non-invasive tool for the estimation of global melatonin production. Due to the easy collection and storage of nails, the long-term information obtained and the multiple functions of melatonin, nail melatonin content might complement dim light melatonin onset, which is commonly measured from plasma/saliva samples, paving the way for melatonin research.

The effectiveness of a nail-biting prevention program among primary school students

PURPOSE

This study aimed to demonstrate the effect of a program called "Do Not Bite Your Nails, Cut Your Nails," which is based on a health promotion model to change the nail-biting habit among primary school students.

DESIGN AND METHODS

This quasi-experimental study was conducted using the pre- and post-test and interrupted time series design. The study sample included 299 students. Nurse observation form and nail follow-up chart were used to evaluate behavioral outcomes. This program was conducted under the guidance of school nurses and lasted 6 weeks. The data were analyzed using McNemar and Cochran Q tests.

RESULTS

The number of those who selected "yes" for "I cut my nails this weekend" and "I didn't bite my nails today" increased. However, the number of the students that selected "yes" for "I pulled out my nails," "I pulled out and ate," "I pulled out my nail skin," "My cuticle bled today," and "My nails hurt today" decreased significantly and statistically compared with pretest, first and second observation, and post-test (P < 0.001). The rate of the students with minimum one abnormal finger was 83.9% according to observations, and 6% following the intervention (P < 0.001). New insights were provided into the program to diminish nail-biting habit.

PRACTICE IMPLICATIONS

The program significantly reduced the nail-biting rate among primary school students. The nurse that implement this program will be able to do a comprehensive evaluation of students' nail-biting habits, perform solution-focused interventions, and prevent advanced complications that might develop in connection to nail-biting. Thus, the effectiveness of nursing implementations will improve in the prevention of nail-biting habit, early diagnosis, and changing students' habits. "Do Not Bite Your Nails, Cut Your Nails" program can be applied again in different schools.