Update on morphea: part I. Epidemiology, clinical presentation, and pathogenesis.

Morphea, also known as localized scleroderma, is a rare fibrosing disorder of the skin and underlying tissues. Morphea is differentiated from systemic sclerosis based on the absence of sclerodactyly, Raynaud phenomenon, and nailfold capillary changes. Patients with morphea commonly have systemic symptoms, such as malaise, fatigue, arthralgias, and myalgias, as well as positive autoantibody serologies. However, involvement of morphea is almost uniformly limited to those tissues derived from the mesoderm. The underlying pathogenesis of morphea is incompletely understood at this time, but ultimately results in an imbalance of collagen production and destruction.