Dear Friend, There are various causes for cracks on penile skin. These include infections like fungal or viral, poor hygiene, malnutrition, dermatitis, balanitis. A clinical examination should be sought. This will help establish the cause and hence help arrive at an appropriate diagnosis and treatment. In the meantime, pay good attention to your diet and ensure there is sufficient intake of vitamins and minerals. A special attention to local hygiene is necessary. Application of moisturiser may help. - Varad Sexology Clinic (Pune)