Infantile systemic hyalinosis: newly recognized disorder of collagen? Four infants with stiff skin and painful joint contractures in the first few months of life are described. Other features included small papules, particularly on the face and trunk, perianal nodules, hyperpigmentation over the metacarpophalangeal joints and over the malleoli, gingival hyperplasia, persistent diarrhea, and failure to thrive. Two of these infants died before the age of 18 months. In each case hyaline material was found in the papillary dermis. Ultrastructurally, there was a distinctive fibrillogranular appearance in which a banding pattern could be observed. This material was also found within membrane-bound vacuoles in macrophages and fibroblasts. It had an appearance and localization identical with that of collagen type VI. These features are similar to those reported in juvenile hyaline fibromatosis. It is believed that these infants have a closely related, but nonetheless distinctive, inherited disorder of collagen. 