skin fissure is a cutaneous condition in which there is a linear-like cleavage of skin, sometimes defined as extending into the dermis.  It is smaller than a skin laceration.

A skin area on which there are many skin fissures is called cracked skin, and is most commonly a result of skin dryness. Ichthyosis is a genetic disorder where there is often severe skin cracking.

Xerosis.

The accentuation of skin markings and fine scale illustrated here are typical of xerosis. The tendency toward dry skin tends to be inherited and is more common in families with a history of atopy. Low humidity, usually related to dry heat during the winter months, is an aggravating factor. Treatment of xerosis is aimed at rehydrating the stratum corneum. Emollients containing urea or alpha-hydroxy acids are particularly effective. Excessive bathing and the use of alkaline soaps must be avoided.