The patient is a 42-year-old man referred by his primary care provider for evaluation of a pigmented area on his right big toe nail. He is an avid tennis player but denies antecedent trauma. Family and personal histories are negative for melanoma. Examination reveals a reddish black pigmentation of the medial nail. There is neither diffusion of pigment nor significant joint changes. Dermoscopic examination reveals well-circumscribed, annular dots dispersed in a homogeneous pattern.
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A subungual hemorrhage, or a subungual hematoma, is a common cause of hyperpigmented nails. It results from blood accumulation within the area between the nail matrix and the nail bed due to an injury or repetitive trauma.1 The condition characteristically presents as brown-black nail pigmentation that moves distally as the nail plate grows.2, 3 However, diagnosis can be difficult when the hemorrhage does not migrate, which occurs in 15% of cases.4 Dermoscopy, a noninvasive tool, may be used to improve accuracy in diagnosis based on color and pattern of pigmentation.
Dermoscopy of the affected nail shows homogeneous and globular patterns in addition to streaks and peripheral fading.1,5 Although affected sites may appear brown or black to the naked eye, they also may exhibit red and purple pigmentation under dermoscopy. The variation in colors is due to breakdown of hemoglobin from the blood into hemosiderin by phagocytes.1 If diagnosis is still questionable considering history, clinical appearance, and/or dermoscopy findings, biopsy would be prudent.
Dr Schleicher is director of the DermDox Center for Dermatology, as well as an associate professor of medicine at Commonwealth Medical College and a clinical instructor of dermatology at Arcadia University and Kings College.
- Mun JD, Kim GW, Jwa SW, et al. Dermoscopy of subungual haemorrhage: its usefulness in differential diagnosis from nail-unit melanoma. Br J Dermatol. 2013;168(6):1224-1229.
- Haenssle HA, Blum A, Hofmann-Wellenhof R, et al. When all you have is a dermatoscope- start looking at the nails. Dermatol Pract Concept. 2014;4(4):11-20.
- Braun RP, Baran R, Le Gal FA, et al. Diagnosis and management of nail pigmentations. J Am Acad Dermatol. 2007;56(5):835-547.
- Zaias N. The Nail in Health and Disease. 2nd edition. Norwalk, Connecticut: Appleton & Lange, 1990.
- Sato T, Tanaka M. The reason for red streaks on dermoscopy in the distal part of a subungual hemorrhage. Dermatol Prac Concept. 2014;4(2):83-85.