<unk> s usually result from trauma, with causes of toe involvement including physical pressure on the toes, such as that seen in surfboarding or windsurfing in which one must maintain balance with the toes, or when exogenous pressure is exerted from poorly fitting shoes.<unk>  beneath the<unk> s may present similar to a melanoma, a confusion that may result if the patient does not communicate the acuteness of onset.
Purpura of the nail bed
Neoplasms of the nailbed
Keratosis punctata of the palmar creases
Longitudinal erythronychia
Reticular pigmented anomaly of the flexures
Spray-on skin
Hypertrichosis simplex of the scalp
Erosive pustular dermatitis of the scalp