Author: Dr Mirain Phillips, Resident Medical Officer, Waikato Hospital, Hamilton, New Zealand. DermNet Editor in Chief: Adjunct A/Prof. Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell. March 2020.
Subungualhaemorrhage is bleeding under a nail where blood is located between the nail matrix and nail plate. Subungual haemorrhage (escape of blood) is also called subungual haematoma (collection of blood).
Subungual haemorrhage is caused by an injury to the nail [1–3].
The types of precipitating injury may include:
A recalled painful event, most commonly involving a finger (eg, crush injury or blunt trauma) which may be associated with an underlying bone fracture.
A non-recalled repetitive micro-trauma, usually involving toes (eg, tight or ill-fitting shoes).
Rarely, subungual haemorrhage is associated with a malignanttumour of the nail unit, such as squamous cell carcinoma or melanoma [4].
What are the clinical features of subungual haemorrhage?
Subungual haemorrhage usually presents as a single discoloured or pigmented nail, which may be painless, tender, or painful.
The patient may remember an injury leading to intense pain due to the pressure from the pooling of blood in an enclosed space and damage to surrounding tissues. Reactive inflammatory changes, such as swelling and erythema, may be observed around the nail fold shortly after the injury.
Trauma may destroy or fracture the nail plate, resulting in the nail being opaque and yellowish due to detachment from the nail bed (onycholysis). The hyponychium (the skin under the free distal edge of the nail) may appear thickened due to blood between the nail plate and the nail bed.
Subungual haemorrhage may appear reddish, purple, brown, black, or a combination of these colours. The variation in colour is related to the duration and stage of healing [2].
A clear proximal margin in the nail plate appears within a few weeks due to normal nail growth after the injury and the discoloured nail plate grows outwards.
Subungual haemorrhage
Subungual haemorrhage
Subungual haemorrhage
How is subungual haemorrhage diagnosed?
Subungual haemorrhage is a clinical diagnosis supported by dermoscopy.
The dermoscopic features of subungual haemorrhage can include [2–4]:
Homogeneous or variable colours (reddish, purple, brown, or black)
Peripheralglobular structures (also called clods) and streaks
Roundish shape with peripheral fading
Periungual haemorrhage
Linear white marks on the nail plate due to loss of transparency
Distal yellowing of the nail plate
Lack of malignant features.
The assessment of a pigmented nail should always evaluate the features that might be suggestive of subungual melanoma [4].
A plain X-ray should be considered for an acute injury to assess for an underlying fracture.
Subungual haemorrhage
Dermoscopy of subungual haemorrhage
Dermoscopy of subungual haemorrhage
What is the differential diagnosis for subungual haemorrhage?
The differential diagnoses to consider for nail pigmentation include:
Nail unit melanoma appears as a pigmented linear or triangular band along the entire length of the nail plate. It develops the following features over time:
Irregularity in pigmentation (light brown, dark brown, grey, or black)
Irregularity in the width and spacing of the pigmented bands
Ulceration or bleeding
Hutchinson sign (pigmentation in the skin proximal to the nail plate) and micro-Hutchinson sign (skin pigmentation visible on dermoscopy but not on clinical examination)
A normal-appearing proximal nail excludes a melanocyticlesion [5].
What is the treatment for subungual haemorrhage?
No treatment is required for subungual haemorrhage in the majority of cases. In the case of repetitive subungual haemorrhage, precipitating factors should be avoided, such as tight or ill-fitting shoes.
In the case of diagnostic uncertainty, the nail should be monitored using photography.
If subungual haemorrhage is acutely painful (< 48 hours after the injury), trephination can be considered [6,7]. Small holes are made in the nail plate to decompress and drain the haematoma. This can be done simply with a hot pointed metal implement [6].
Occasionally the nail plate is best removed, and the nailbed surgically repaired. A surgical opinion should be sought if there is an underlying fracture [7] or for biopsy if melanoma cannot be excluded.
What is the outcome for subungual haemorrhage?
Subungual haemorrhage resolves slowly over months to years, with toenails taking longer than fingernails to recover.
References
Nevares-Pomales OW, Sarriera-Lazaro CJ, Barrera-Llaurador J, et al. Pigmented lesions of the nail nnit. Am J Dermatopathol. 2018;40(11):793–804. doi:10.1097/DAD.0000000000001106.PubMed
Alessandrini A, Starace M, Piraccini B. Dermoscopy in the evaluation of nail disorders. Skin Appendage Disord. 2017;3(2):70–82. doi:10.1159/000458728.PubMed Central
Mun JH, Kim GW, Jwa SW, et al. Dermoscopy of subungual haemorrhage: its usefulness in differential diagnosis from nail-unit melanoma [published correction appears in Br J Dermatol. 2013 Sep;169(3):727]. Br J Dermatol. 2013;168(6):1224–9. doi:10.1111/bjd.12209.PubMed
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. Br J Dermatol. 2010;162(4):765–71. doi:10.1111/j.1365-2133.2009.09594.x. PubMed
Fountain JA. Recognition of subungual hematoma as an imitator of subungual melanoma. J Am Acad Dermatol. 1990;23(4 Pt 1):773–4. doi:10.1016/s0190-9622(08)81099-7.PubMed
Farrington GH. Subungual haematoma--an evaluation of treatment. Br Med J. 1964;1(5385):742–4. doi:10.1136/bmj.1.5385.742.PubMed Central