20 TILBURY FOX;
I'herpes iris s'applique a une variete d'hydroa aigu, plus rare en- core que I'hydroa successif et clironique, et non pas a I'herpes para- sitaire, a anneaux multiples et conrentriques."* He then adds an excellent history of another typical case of the herpes iVis of Bate- man .
What is lacking in this account of hydroa vesiculeux is the proof that herpes iris and the other and more usual phase of Bazin's hy- droa vesiculeux are identical. Bazin gives no cases of this other phase, nor any in which the evidences of transitional forms were present together in the same patient. On the contrary, Bazin's description of herpes iris shows that the eruption existed by itself in all its typical features. No one can doubt the herpetic alliances of the two things, but that is, clinically speaking, different from identity.
It must be noticed here that Bazin's example in this respect, in confusing, in his first account of hydroa, ordinary hydroa vesiculeux with herpes iris, and the ignoring of Willan's and Bateman's de- scription of the latter, has been followed by most French writers, and by others in our own country. In fact, the designation hydroa has with many actually supplanted that of herpes iris, and one is tempted to ask whether those who have dealt thus with the two terms really know what Willan and Bazin respectively meant by herpes iris and hydroa. For instance, a couple of years ago I noticed certain models in the museum of the Hopital St. Louis of typical herpes iris of Willan, labelled Hydroa by M. Gibert, who, in fact, thereby ignores Bazin's more usual form of eruption designated by him by that term. Mr. Hutchinson, too, in his report on Hydroa in the British Medical Journal for 1870, seems to have fallen into the same use of the term hydroa. f Duhring,;|; Hilton Fagge,§ and others, in referring to hydroa, generally agree in their application of the term to herpes iris. They, however, seem to be unaware of the fact that Bazin's hydroa vesiculeux included something more than her- pes iris of Willan. Bazin clearly speaks of one form of his hydroa as commencing as an erythematous papule, becoming vesicular in the centre, and then slightly umbilicating, collapsing, and rapidly crusting, the periphery being left as a ring of fluid to be more slowly absorbed, and as quite distinct from the herpes iris aspect, which has a secondary peripheral ring of vesicles.
- The ringed vesicular form of tinea circinata is of course well known, but very
rarely it may probably assume a form more closely simulating the eruption of her- pes iris, but then the spots will be few or isolated, and there can be no difficulty in the diagnosis. Of this nature, possibly, were the isolated spots described as herpes iris by Cazenave and Burgess (Cazenave's Manual of Disease of the Skin, 2d edit, by Burgess, p. 131), one occurring on the front of the thigh, and one on the forehead. It is probable that this ringed vesicular tinea circinata may occur extensively distributed over the body, but certainly it is now excessively rare in this country.
f Mr. Hutchinson includes, however, certain vesicating erythemas besides herpes iris under the term hydroa.
A Practical Treatise on Diseases of the Skin, 1877.
I Catalogue of Guy's Hospital Museum Skin Models, 1876.
