The dermal barrier in systemic sclerosis and other rheumatic diseases.

Hyaluronidase has been shown to increase the rate of spread of intradermally injected solutions in animals (Chain and Duthie, 1939, 1940) and the whole subject of spreading factors was reviewed by Duran-Reynals (1942). Holborow and Keech (1951) studied the effects of hyaluronidase in accelerating the rate of spread of a solution of haemoglobin injected intradermally in normal human subjects and in patients with rheumatic fever and found no significant differences. In three cases of dermatomyositis, the hyaluronidase appeared to have no significant spreading effect until hypersensitivity to the enzyme developed, and the authors suggested that, in dermatomyositis, the hyaluronic component of the skin is either deficient or is unresponsive to testicular hyaluronidase. Kellgren, Ball, and Tutton (1952) compared the rates of disappearance of the palpable blebs produced by the intradermal injection of isotonic saline with and without hyaluronidase in normal and acromegalic subjects, and found that, whereas the rates of disappearance of the saline blebs were comparable in the two groups, the hyaluronidase caused more rapid disappearance of the blebs in the normal than in the acromegalic subjects. In normal subjects, the blebs containing hyaluronidase tended to persist longer in the younger subjects who might still be growing. The purpose of this communication is to report the results obtained on applying this test in normal subjects and in patients suffering from systemic sclerosis or other connective tissue diseases. Some of the factors concerned in the disappearance of the blebs were investigated and the possible significance of the results is discussed.