Crack lines on the skin of the lower legs may be caused by ichthyosis, dry eczema and other diseases. 1. Ichthyosis: ichthyosis is mainly divided into congenital and acquired two kinds, and the vast majority of ichthyosis is genetic, for hereditary ichthyosis. Symptoms of different types of ichthyosis have their own characteristics, mainly manifested as dry skin, flaking, ichthyosiform lesions, winter symptoms are obvious, summer symptoms reduce. 2. Dry eczema: Due to various internal and external factors, the barrier function of the skin is damaged. Dry environmental conditions in fall and winter may lead to dry, flaky, fissure-like erythema of the calf skin, accompanied by intense itching. Cracks in the skin of the calves, but also to understand whether it is related to growth lines. It is recommended not to blindly use medication to avoid masking the condition. You can go to the hospital dermatology department for examination to clarify the cause.