Subungual hemorrhages, also called subungual haematomas, are collections of blood in the space between the nail bed ormatrix and the nail plate and may result from an acute injury or repetitive minor trauma to the nail apparatus. Their most frequent location are the thumb and the hallux.
Most subungual hemorrhages are clinically evident with well-circumscribed dots or blotches of red to black pigmentation but in some cases a subungual hemorrhage may mimic a subungual melanoma. In these cases dermoscopy may help to eliminate differential diagnosis.
The clinical features of subungual haemorrhages are characterized by well-circumscribed dots or blotches with a red to red–black pigmentation. Dermoscopic examination of subungual hemorrhages shows in most cases the presence of several colors, with purple-black being the most frequent color. In the case of an acute injury the main colors visualized change over time, in early lesions the colors are mostly pink, purple and red, whereas in older lesions colors tend to be darker purple-black, red black, and brown-black. Lesions migrate proximally as the nail plate grows except in 15% of the cases.
The most frequent dermoscopic structure is homogeneous blotches, but globular patterns and streaks (also called splinter hemorrhages) can be seen as well in combination or alone. Other dermoscopic features that can be present in subungual hemorrhages are peripheral fading and periungual hemorrages.
Subungual hemorrhage are frequently seen in subungual melanomas (23%), therefore when a subungual hemorrhage is suspected, subungual melanoma should always be eliminated in a two step algorithm. In the first step, the presence of subungual hemorrhage associated features should be assessed. In the second step, the presence of other nail pigmented lesions should be assessed, especially melanoma-related features (Hutchinson sign, longitudinal irregular line, triangular shape of the band, vascular pattern, and ulcer). Subungual hemorrhages don’t show signs of melanoma-related features, in the presence of such lesions, a biospy should be made exclude a melanoma.
Digital dermoscopy follow-up can be performed in unclear cases, it consists in a first short evaluation after 3 to 4 months followed by another evaluation a year later. It can show, a disappearance of the lesion, its migration with nail growth and the darkening of the previous colors with no appearance of melanoma-related dermoscopic features.
- Mun J-H, Kim G-W, Jwa S-W, Song M, Kim H-S, Ko H-C, et al. Dermoscopy of subungual haemorrhage: its usefulness in differential diagnosis from nail-unit melanoma. British Journal of Dermatology 2013;168:1224–9.
- Braun RP, Baran R, Le Gal FA, Dalle S, Ronger S, Pandolfi R, et al. Diagnosis and management of nail pigmentations. Journal of the American Academy of Dermatology 2007;56:835–47.
- Ronger S, Touzet S, Ligeron C, Balme B, Viallard AM, Barrut D, et al. Dermoscopic examination of nail pigmentation. Archives of Dermatology 2002;138:1327–33.
- Phan A, Dalle S, Touzet S, Ronger-Savlé S, Balme B, Thomas L. Dermoscopic features of acral lentiginous melanoma in a large series of 110 cases in a white population. British Journal of Dermatology 2009;162:765–71.