18 TILBURY FOX;
pears to be recognized, or ])artly so, by certain dermatologists as, for example, by Gibert, and Diday and Doyon. Bazin's first variety is made to include H. iris, and the third is regarded as a pem- phigus by some {P. a petites bulles).
In Germany, Bazin's views are ignored, and such a disease as hydroa is practically imknown as such.
In America, where German work and views are so closely followed, it is only of late that attention has been called to the subject, and especially by Dr. George Fox, of New York, who in a recent dis- cussion* says, "Thus the term pemphigus is applied to eruptions, to which it is inappropriate simply because of the bullous character of the lesion ; . . . whereas there are other eruptions presenting bullae which are similar anatomically, but the disease is of a very different nature," and to these he would apply the term hydroa provisionally.
The whole subject is new ground for many fertile and excellent collaborateurs in America.
In England, almost all recent writers on skin diseases seem to have tacitly adopted the view that there was ample justification for found- ing a special group hydroa_, but no one appears to have clear and definite opinions what should be included within it. It is certain that vesicating erythema, herpes iris, the hydroa of Bazin, pemphigus, and other diseases have not been properly differentiated.
In the last edition (third) of my work on " Skin Diseases," I gave a sketch of what I thought hydroa included, viz., Bazin's varieties of hydroa and something more in the direction of herpetiform and pemphigoid cases. Since that time, in hospital and private practice, I have enjoyed considerable experience of hydroa in all its phases, and the result of my observations will now be given.
The subject is confessedly a difficult one. I propose to take Bazin's description of hydroa as a starting-point, and to substitute for his three varieties those of simplex, herpetiforme, and prurigi- nosum.
SECTION II.— HYDROA SIMPLEX; HYDROA HERPETIFORME.
I now proceed to describe hydroa vesiculeux of Bazin, which I shall amplify into two clinical aspects, viz., those oi H. simplex and ar. herpetiforme.
Bazinf describes H. vesiculeux as one generally confounded with erythema papulatum, and he gives the following sketch of it : The eruption is usually, but not always, preceded by some malaise, anor- exia, and slight febrile disturbance, and it appears, accompanied by some local itching and burning, as red, rounded, defined, pro- jecting spots, varying in size from a lentil to a twenty-centime piece, on the backs of the hands and wrists and about the front of the knees. On the second day of their existence the red spots become
- Archives of Dermatology, January, 1878, p. 64; see also July, 1878, for
an additional paper. •}- Loc. cit.
