Subungual Melanocytic Lesions in Pediatric Patients

Seven Plus One Steps to Assess Pigmented Nail Bands (Melanonychia Striata Longitudinalis)

Melanonychia striata longitudinalis might involve one or more fingers and/or toes and might result from several different causes, including benign and malignant tumors, trauma, infections, and activation of melanocytes that might be reactive or related to the pigmentary trait, drugs and some rare syndromes. This broad differential diagnosis renders the clinical assessment of melanonychia striata particularly challenging. Nail matrix melanoma is relatively rare, occurs almost always in adults involves more frequently the first toe or thumb. The most common nail unit cancer, squamous cell carcinoma / Bowen disease (SCC) of the nail matrix is seldom pigmented. Histopathologic examination remains the gold standard for melanoma and SCC diagnosis, but excisional or partial biopsies from the nail matrix require training and is not routinely performed by the majority of clinicians. Furthermore, the histopathologic evaluation of melanocytic lesions of the nail matrix is particularly challenging, since early melanoma has only bland histopathologic alterations. Dermatoscopy of the nail plate and its free edge significantly improves the clinical diagnosis, since specific patterns have been associated to each one of the causes of melanonychia. Based on knowledge generated and published in the last decades, we propose herein a stepwise diagnostic approach for melanonychia striata longitudinalis: 1) Hemorrhage first 2) Age matters 3) Number of nails matters 4) Free edge matters 5) Brown or gray? 6) Size matters 7) Regular or irregular and, finally, "follow back".

Adult and Pediatric Nail Unit Melanoma: Epidemiology, Diagnosis, and Treatment

Nail unit melanoma (NUM) is an uncommon form of melanoma and is often diagnosed at later stages. Approximately two-thirds of NUMs are present clinically as longitudinal melanonychia, but longitudinal melanonychia has a broad differential diagnosis. Clinical examination and dermoscopy are valuable for identifying nail findings concerning malignancy, but a biopsy with histopathology is necessary to confirm a diagnosis of NUM. Surgical treatment options for NUM include en bloc excision, digit amputation, and Mohs micrographic surgery. Newer treatments for advanced NUM include targeted and immune systemic therapies. NUM in pediatric patients is extremely rare and diagnosis is challenging since both qualitative and quantitative parameters have only been studied in adults. There is currently no consensus on management in children; for less concerning melanonychia, some physicians recommend close follow-up. However, some dermatologists argue that the "wait and see" approach can cause delayed diagnosis. This article serves to enhance the familiarity of NUM by highlighting its etiology, clinical presentations, diagnosis, and treatment options in both adults and children.

[Common nail diseases in children and adolescents : Recognize, advise, treat]

There are a number of nail diseases that primarily occur in children and adolescents. Many of these nail changes are physiologic and are only transient. Thus, they do not need any therapy. Infectious nail diseases or nail involvement in chronic inflammatory dermatoses can be found in both children and adults, and may require specific treatment. Nail pigmentation such as longitudinal melanonychia occur significantly less frequently in children than in adult patients, and have different causes and a better prognosis. Knowledge about these child-specific peculiarities of nail diseases is necessary in order to provide the best possible advice to parents and to offer appropriate treatment. This article focuses on the most common and important nail diseases in children and adolescents and their treatment.