What is transverse melanonychia?
Melanonychia is a result of increased melanin deposition in the growing nail beds. Transverse, longitudinal and diffuse form of melanonychia have been described. 1 The mechanism of melanonychia can be due to melanocytic activation or melanocytic hyperplasia.
Can melanonychia be horizontal?
Transverse melanonychia. This type of melanonychia appears as a band that runs across your nail from one side to the other.
What are transverse lines on nails?
Transverse lines of the nails can be caused by a growth arrest in the nail matrix or changes in the color of the nail itself, and may suggest underlying systemic conditions or the effects of a toxin or drug.
Can melanonychia be longitudinal?
Longitudinal melanonychia, also called “melanonychia striata,” describes a pigmented, brown to black, longitudinal streak of the nail plate due to increased activity of melanocytes or melanocytic hyperplasia in the nail matrix, with increased melanin deposition in the nail plate [1,2].
What is the difference between melanoma and melanonychia?
The most serious disease of the nail unit, melanoma, primarily presents with melanonychia. However, melanonychia most often occurs as a result of benign etiologies such as nail matrix melanocytic activation, nail matrix melanocytic hyperplasia, and nail invasion by melanin-producing pathogens.
How do you know if melanonychia is cancerous?
Your doctor will look primarily for signs that your melanonychia may be malignant. The signs of possible nail melanoma include: discoloration which is more than 3 millimeters wide or has increased in size. irregular brown pigmentation.
How do you know if melanonychia is benign?
How to Tell If the Cause Is Benign. Non-cancerous longitudinal melanonychia typically has the appearance of light to dark brown stripes that are parallel and regular in color, thickness, and spacing. The border will be clearly defined and less than 3 millimeters (mm) in width, or roughly 1/10th of an inch.
Can benign melanonychia become malignant?
In some cases, it can be harmless, or benign, but in others, it can be malignant. There are many possible causes of melanonychia via melanocytic activation, as well as factors that can make it more likely.
What causes Beau lines?
Causes of Beau’s lines include high fevers caused by infection, severe cutaneous inflammatory diseases such as Stevens–Johnson syndrome or Kawasaki disease, a reaction to medications, and acrodermatitis enteropathica. Beau’s lines may occur in infants, 4–10 weeks of age, as a result of the stress of delivery.
Can longitudinal melanonychia be benign?
There are three types of longitudinal melanonychia in this category: lentigo, nail matrix nevus, and subungual melanoma. The former two conditions are benign lesions, while the latter is malignant.
How do you know if melanonychia is malignant?
Therefore, it is important to distinguish malignant melanoma from benign melanonychia. History, physical examination, dermoscopy, and biopsy are obtained or performed to help determine the diagnosis.