History of skin thickness assessment and the Rodnan skin thickness scoring method in systemic sclerosis

The pathology of skin involvement in systemic sclerosis (or scleroderma) was first described in detail in 1892. In this article, we trace the history of cutaneous scleroderma and the evolution of thinking of scholars who have addressed this topic. We focus on skin histopathologic abnormalities and both clinical and laboratory techniques proposed for quantifying skin thickening and mobility. We examine the development of the simple bedside physical examination method of Dr Gerald Rodnan, first published in the 1970s and subsequently modified by others in the early 1990s (modified Rodnan skin score). This method has been found to be the only completely validated technique for assessing skin thickness in systemic sclerosis. Now nearly 50 years later, the modified Rodnan skin thickness scoring system remains the gold standard for use in both systemic sclerosis clinical trials and observational studies.