A 47-year-old man consulted his Dermatologist for some “dark lines” which he noted over his fingernails. There was no history of trauma to the fingers. He was otherwise asymptomatic. The lesions had been static in size for the past month and no other skin lesion were noted.
On examination, there were longitudinal black streaks over the left index, left middle and right index fingers. The fingernail plates were normal. There was otherwise no petechiae, purpura or ulcers. No hyperkeratotic lesions were found on the extensor surfaces or on the scalp. Cardiovascular examination showed no murmur.
Diagnosis
Splinter haemorrhages usually presents as dark-red, thin, longitudinal lines on the distal portion of the fingernails. The linear configuration is related to the longitudinal orientation of the nail bed capillaries. The most common cause of splinter haemorrhages is trauma, psoriasis and onychomycosis.
Splinter haemorrhages may often be a useful clinical sign for underlying systemic conditions including infective or non-bacterial thrombotic endocarditis (marantic endocarditis), vasculitis, trichinosis and anti-phospholipid syndrome. Features including multiple haemorrhages, involvement of more than one nail and haemorrhage in the proximal part of the nail would be more suggestive of an underlying systemic etiology.