Bullous Diseases and Anomalous forms of Bullous Eruption

Under this head we include the diseases which are especially characterized by the occurrence of the bullae as primary and essential phenomena. A bulla is a large por­tion of the cuticle detached from the skin by the interposition of a transparent watery fluid. In fact, a bulla is a large vesicle. In the wide sense of the term several diseases are really bullous, such as erysipelas, herpes, pemphigus, rupia, eczema of the fingers, and impetigo contagiosa. But of these there are only two that really rank under the term bullous - i.e., herpes and pemphigus. Erysipelas belongs to the class of zymotic diseases; rupia is always syphilitic, and of course it is grouped under that head; the bulla produced by the coalescence of vesicles in eczema is an accidental and secondary phenomenon; and in impetigo contagiosa, the primary stage is a vesicle and not a bulla, the secretion subsequently becoming seropurulent, whilst the general behaviour and outward aspect of the disease are those of an impetigo. Besides, herpes and pemphigus are peculiar and alike in regard to the influence of the nervous system in their production. Therefore, true bullous diseases, or those which are probably of neurotic origin, and in which the bullae are primary, with transparent contents, are herpes and pemphigus.


Herpes and pemphigus might have been placed under the head of neurotic diseases, but then many others must have been included, such as urticaria, pityriasis rubra, etc., with them, if we carried out the idea of collecting together under one head all those diseases which primarily originate in disturbance of the nervous .system and arranged them upon a pathological basis. As we have classified diseases, however, clinically, we place herpes and pemphi­gus under the convenient but most unscientific term, "bul-lous inflammation," because it is to changes implied by that term that the practitioner first directs his attention in the matter of diagnosis and treatment.

Some anomalous forms of eruption will be noticed at the latter part of this chapter.