Psoriasis

Psoriasis is "a common genetically determined, chronic, inflammatory skin disease characterized by rounded erythematous, dry, scaling patches. The lesions have a predilection for nails, scalp, genitalia, extensor surfaces, and the lumbosacral region. Accelerated epidermopoiesis is considered to be the fundamental pathologic feature in psoriasis."

It is a chronic inflammatory disease, and it is most realistic to think of management rather than cure. In a given patient, it might be a minor annoyance, such as hardened patches of skin over the elbow or another moving surface, which rarely crack and bleed. In another patient, it can be completely disabling, with painful, disfiguring lesions that interfere with common activities of daily life. People with severe disease have shortened lifespans.

Genetic factors seem to predispose to the disease manifesting itself, but there are poorly understood environmental triggers.

Older treatments still can be useful and relatively benign for mild cases. Since the mechanisms of disease involve inflammatory response, management of complex cases often requires immunosuppression, with the attendant risks. Careful risk-benefit analysis must be made in every case.