The skin is the largest organ of the body and the most substantial part of the integumentary system, along with the hair, nails and exocrine glands. Skin has several layers that serve a number of important functions. The epidermis, basement membrane zone, dermis and the subcutaneous tissue help protect against infection, chemicals, and ultraviolet radiation. In addition to maintaining homeostasis, the skin also regulates a lot of biochemical processes (such as ultraviolet-induced synthesis of vitamin D).
But things can go wrong. Skin conditions can be the result of infections (bacterial, fungal, viral), trauma, papulosquamous disorders, rashes (eczema, psoriasis, etc), tumors, cutaneous signs of systemic diseases, and others , . Treatment depends on the type of skin disorder. Some require nothing more than simple skin hydration, while others need specialized treatments to fight infection, regulate inflammatory response or reduce tumor mass.