If you are engaged in certain sports or athletic activities and experience painless black spots on the heels of your feet, this explanation should help. The appearance of painless bluish-black dots on the heels of the feet that are called black heel, talon noir or calcaneal petechiae. This also may occur on the palms, and when this happens it is called black palm or tâche noir. These spots are caused by mechanical trauma.
The word tâche is a French word, that used in this instance, has a connotation of “hard work” or “a hard task” so that the term tâche noir refers to black marks coming about from a hard task (done with the hands). Not to be confused with tache noir, which is a black raised mark from a tick bite, with tache referring to a spot, stain, mark, etc.
Black heel condition is associated with sports that involve sudden starts and stops that cause shearing stress, such as basketball, tennis, lacrosse, or volleyball. The black dots are caused by intra-epidermal bleeding and they appear as rows on the posterior or posterolateral heel. They most often occur right at the back edge of the underside of the heel.
Any repetitive jumping, turning, or cutting can lead to this shear stress which can cause the small blood vessels in the skin of the heel to bleed. The trauma to the vessels is caused by the epidermis sliding over the papillary dermis, damaging the delicate papillary capillaries. These asymptomatic spots will not prevent participation in any activity, and they tend to be more prevalent in younger athletes. They are usually asymptomatic although occasional pain or tenderness may occur.
Black Palm occurs in golfers, weightlifters, gymnasts, tennis players, and mountain climbers, usually on the thenar eminence, which is the fleshy area of the palm at the base of the thumb. It is possible for anyone engaged in resistance training, bodybuilding, or strength training to experience this but it is more likely in younger lifters.
The black dots suddenly appearing on the heel or palm, although they are painless, can cause an athlete to worry as they may mistake these benign spots for cancer or some other skin condition. The lesions can be pared down and removed by a dermatologist but treatment is not really necessary and paring the spots down is more important as a diagnostic tool than a treatment. If the spots are not easily removed by paring, then other conditions such as a malignant melanoma may be suspected. Due to the appearance of these macules resembling a melanoma, you should have them checked by your doctor if you are unsure. You may not automatically know the appearance of the lesions is associated with your sports activity, since there may be no pain involved as the damage occurs which leads to the spots. The lesions should usually go away by themselves.
To prevent black heel or black palm, minimize shear stress by wearing well-fitted shoes or appropriately padded socks, or gloves. If the condition is present, you can keep playing or exercising, but some padding on the heel or palm may be necessary to stop or minimize recurring damage so that the spots can disappear.