Final answer:
A fissure is a crack in the skin caused by factors such as mechanical damage, heat, pressure, friction, or skin conditions like dermatitis. These fissures may allow microbes to enter and potentially lead to infections.
Step-by-step explanation:
A fissure in dermatological terms can be described as a crack in the skin that can be due to various causes. These causes of a fissure might include mechanical damage due to sharp objects, heat, excessive pressure or friction, and also certain skin conditions like contact dermatitis which can be triggered by exposure to specific irritants like latex. Conditions like cheliosis, which is characterized by cracks or sores on the outer surface of the lips, also display such fissuring, as well as skin inflammations like seborrheic dermatitis. Damage to the skin by fissures can lead to further complications by providing an entry point for microbes, which can potentially lead to infections, both localized and systemic.