Acromelanosis.. Pigmentation is widespread in the dorsal distances of the fingers and forebears common in people with dark skin

Acromelanosis:
Hyperpigmentation is widespread in the dorsal distances of the fingers and forebones commonly found in dark-skinned people.
Pigmentation begins in infancy or childhood and grows deeper and deeper.
There may be excessive pigmentation on the emotional surfaces of the joints in some joints of the greater emotion.
The condition should be differentiated from hyperpigmentation induced by repeated illness.