Related Experiment Video
Updated: May 31, 2026

Laser Microdissection-Based Protocol for the LC-MS/MS Analysis of the Proteomic Profile of Neuromelanin Granules
Published on: December 16, 2021
Onychophagia-induced longitudinal melanonychia
Rachel B Anolik1, Kara Shah, Adam I Rubin
1Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Nail biting can cause longitudinal melanonychia, a rare condition appearing as pigmented bands on nails. Dermatologists should inquire about nail biting habits in patients presenting with melanonychia.
Area of Science:
- Dermatology
- Nail Disorders
Background:
- Longitudinal melanonychia is a common nail condition, often benign.
- It typically presents as a brown or black band on the nail plate.
Observation:
- A 13-year-old girl presented with new longitudinal pigmented bands on multiple fingernails and one toenail.
- The patient had no prior history of nail abnormalities.
Findings:
- The pigmented bands were attributed to onychophagia-induced longitudinal melanonychia.
- This represents a rare presentation of nail biting's effect on nail pigmentation.
Implications:
- Highlights the importance of considering nail biting as a cause of melanonychia.
- Dermatologists should routinely ask patients about nail-biting habits, even if not volunteered.
More Related Videos
05:14Standardized Data Acquisition for Neuromelanin-Sensitive Magnetic Resonance Imaging of the Substantia Nigra
Published on: September 8, 2021
06:15Anterior High-Resolution Optical Coherence Tomography in the Diagnosis and Therapeutic Monitoring of Ocular Surface Squamous Neoplasia
Published on: August 9, 2024
Related Concept Videos
Accessory Structures of the Skin: Nails
The main components of a nail include the following.
Nail Plate: The nail plate is the visible portion of the nail that extends beyond the fingertips or toes. It is a hard, translucent...
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Diabetic Neuropathy
Chronic Pancreatitis II: Pathophysiology
Type I Diabetes III: Clinical Manifestations
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...