Cause Of Melanonychia Research Articles

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".

Melanonychia and subungual papule in a middle-aged man

Melanonychia and subungual papule in a middle-aged man

Melanonychia – Clues for a Correct Diagnosis

Melanonychia represents a brown to black discoloration of the nail plate that may be induced by benign or malignant causes. Two main mechanisms are involved in the appearance of melanonychias, i.e., melanocytic activation and melanocytic hyperplasia. The distinction between the two can be made based on the medical history of the patient, the clinical picture, dermoscopy, and histopathological examination and is essential for the adequate management of the patient. We review the main causes of melanonychia, with emphasis on the clues to the diagnosis of subungual melanoma.

Cyclophosphamide-induced melanonychia

A case of drug-induced melanonychia due to cyclophosphamide is described in a patient with lupus nephritis. This resolved completely at 20 weeks after stopping the drug. Clinicians should be aware of the causes of melanonychia, and, if drug-induced melanonychia is suspected, the offending drug should be stopped whenever possible.

Distinct Patterns and Aetiology of Chromonychia.

Abnormal colouring of the nails may be a sign of underlying systemic or local disorders. This study investigated the prevalence and causes of chromonychia as a whole, as well as of each subtype. Among 163 patients with chromonychia, trauma was the pathogenesis in up to 20.9% (34/163) of cases. The most common subtype was melanonychia (54.0%; 88/163), followed by leukonychia (23.9%), red (8.6%), green (6.7%), yellow (4.9%) and blue (1.8%) nails. Nail matrix naevus (33.3%; 29/88) was the most common cause of melanonychia, while skin diseases (41.0%; 16/39), such as psoriasis (75%, 12/16) and alopecia areata (18.8%; 3/16), in addition to systemic diseases (33.3%; 13/39) including anaemia (38.5%, 5/13) and chronic renal failure (15.4%; 2/13) were the dominant causes of leukonychia. As chromonychia may be the first or only sign of an underlying disorder, it should alert physicians and patients to the need for a prompt and thorough evaluation.

Dermoscopic patterns of fungal melanonychia: A comparative study with other causes of melanonychia

Diagnosing fungal melanonychia (FM) is often difficult because it mimics melanonychia caused by other factors. Dermoscopy is helpful in the setting of nail pigmentation. However, the diagnostic characteristics of FM on dermoscopy are not fully elucidated. We sought to determine the dermoscopic characteristics of FM. We evaluated the dermoscopic patterns of FM diagnosed at 2 university hospitals from January 2010 to February 2016. We included nail matrix melanocytic activation, nail matrix nevi, and nail unit malignant melanomas as control groups for comparison. In all, 18 FM, 24 melanocytic activation of the nail matrix, 27 nail matrix nevi, and 11 malignant melanoma cases were analyzed. Statistical analysis revealed that yellow color, multicolor pattern, nonlongitudinal homogenous pattern, reverse triangular pattern, subungual keratosis, white or yellow streaks, and scales on the nail were more frequent in FM. However, gray color, longitudinal pattern, and pseudo-Hutchinson sign were less frequent in FM than in controls. This was a retrospective study from 2 university hospitals, with a small sample size. The results revealed distinctive dermoscopic patterns for FM. Therefore, dermoscopy can beauseful ancillary tool for diagnosing FM.

Diagnostic criteria for and clinical review of melanonychia in Korean patients

Melanonychia may be the presenting sign of ungual melanoma. However, there are insufficient basic clinical data for melanonychia in Korean patients. We sought to identify basic clinical data and devise a classification algorithm for melanonychia. In all, 275 patients with melanonychia who visited our clinic from January 2002 to August2014were included in this study. We reviewed medical records, clinical and dermoscopic photographs, and histopathologic findings and we assessed demographics (eg, age); medical (eg, systemicdiseases), family, and trauma (eg, nail biting) history; and physical findings (eg, affected number and site). The 5 most common causes of melanonychia in Korean patients were subungual hemorrhage (29.1%), nail matrix nevus (21.8%), trauma-induced pigmentation (14.5%), nail apparatus lentigo (11.6%), and ethnic-type nail pigmentation (8.0%). Melanoma was diagnosed in 6.2% of patients. Ethnic-type nail pigmentation was commonly identified. This is a retrospective study from a single center. We propose a revised diagnostic algorithm for melanonychia to assist in the evaluation of this condition.

Dunkler Nagel

A dark colored pigmentation of nails can be due to a subungual malignant melanoma. There are, however, many other benign causes and this differentiation is an important challenge in dermatological practice. When should nail pigmentation be clarified by histological investigations? This article gives a survey of the literature on this topic and a review of own experiences with clinical case examples. The various causes of melanonychia are presented and criteria for the early recognition of melanoma of the nail matrix are formulated. The width and depth of color of longitudinal melanonychia do not allow any conclusions on the dignity. If the nail striation is proximally broader than distally, this is evidence of a proliferative event. Confirmation of a subungual hemorrhage does not exclude a malignancy per se. Also detection of pigmentation due to fungi does not exclude the additional presence of a subungual melanoma. A systematic clinical analysis using clear criteria leads to a working diagnosis and suitable treatment. An early and correct designation of nail pigmentation can avoid unnecessary nail interventions but can also be life saving.

Melanonychia

Melanonychia, or melanin-derived brown-to-black nail pigmentation, is a diagnostic challenge for clinicians. 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. Regrettably, patients with nail apparatus melanoma are often initially misdiagnosed, and due to diagnostic delays of an average of 2 years, melanoma of the nail unit carries a poor prognosis. Having a thorough knowledge of the various causes of melanonychia and using a systematic approach when evaluating brown-to-black nail pigmentation may help prevent misdiagnosis and thereby improve prognosis.

Onycotrychia?: subungual hair follicle as another cause of longitudinal melanonychia or pigmentation – Hair follicle as cause of melanonychia

Onycotrychia?: subungual hair follicle as another cause of longitudinal melanonychia or pigmentation – Hair follicle as cause of melanonychia

Dealing with Melanonychia

Melanonychia describes a brown or black pigmentation of the nail plate caused by the presence of melanin. In this article, we review possible causes of melanonychia and discuss the main problems of management of patients with this condition. The goal in the management of melanonychia is early diagnosis of melanoma of the nail matrix and bed. Melanoma of the nail bed is also known as subungual melanoma. We discuss clinical, dermoscopic features that may help the clinician in selecting lesions that should have excisional biopsy and evaluate different options for the excision. Addressing melanonychia is still a difficult task, and the correct management of pigmented bands in children is far from established. Dermoscopy is possibly a useful tool but the real benefit of this technique, screening lesions to determine which ones need to be removed, remains to be proven.

Fungal Melanonychia

Melanonychia is characterized by tan, brown, or black pigmentation within the nail plate. Fungal melanonychia is rare and may simulate longitudinal melanonychia caused by melanocytic lesions. We report six cases of fungal melanonychia which were confirmed histopathologically or mycologically. On culture, Candida and/or Aspergillus species were isolated in four patients. The nail pigmentation improved after treatment with antifungal agents in all cases, but one patient experienced a new lesion on another nail after cessation of treatment. Fungal infection should be considered as a cause of melanonychia, and fungal melanonychia should be differentiated from the melanonychia caused by melanocytic lesions, particularly by subungual melanoma.