A Clinical Study of Morphologic Alterations of Lunula of Fingernail in Dermatologic Patients / 대한피부과학회지

ABSTRACT

BACKGROUND: The lunula is the visible portion of the distal nail matrix that extends beyond the proximal nail fold. It has a primary structural role in defining the free edge of the distal nail plate. The size of the lunula is variable not only among persons, but also for each digit in the same person. Alterations in the morphologic features or color of the lunula can be an indication of either a cutaneous or a systemic disorder. OBJECTIVE: The purpose of this study was to examine the size, visible pattern and morphologic alterations of lunula of fingernails according to age and sex in dermatologic patients. METHODS: During a 6-month-period from Jan to Jun, 2001, we examined the size, pattern and morphologic alterations of lunula of fingernails according to age and sex in 420 dermatologic patients visiting Hanyang University Hospital. Anolunula and lunular dyschromia were also evaluated in association with cutaneous and systemic disorders. RESULTS AND CONCLUSIONS: 1. Fingernail lunula was observed in highest frequency on thumbnail in both sexes. Lunulae of all fingers showed increased tendency of frequency with age until 50-59-year-old group in male and until 40-49-year-old group in female. 2. In both sexes, thumbnail had the longest length of lunula, followed by index, middle, ring and little fingernail. The length of lunulae of all fingers showed a tendency to increase with age until 50-59-year-old group. With the exception of both thumb and littlel fingers, male had the longer lunulae than female(p<0.05). 3. In both sexes, thumbnail had the widest width of lunulae, followed by middle, index, ring and little fingernail. And the width of lunulae of all fingers showed a tendency to increase with age. With the exception of left little finger, male had the wider lunulae than female(p<0.05). 4. In male, R(L)1 type was the most common observed pattern of lunula for 0-9-year-old group. Thereafter R(L)12345 and R(L)1234 types comprised more than half cases. In female, R(L)1 type was the most common pattern until 10-19-year-old group. Thereafter R(L)12345 and R(L)1234 types comprised more than half cases as male. 5. Anolunula was observed in 14(3.3%) of 420 study patients and associated with several cutaneous and/or systemic disorders including brachyonychia, alopecia areata, renal failure and chronic alcoholism. 6. Lunular dyschromia in confluent/spotted form or in longitudinal band were observed in 13(13.1%) of 420 study patients and associated with several cutaneous and/or systemic disorders including diabetes mellitus, renal failure, and iron deficiency anemia.