Diagnostic features

Diagnostic features are - its apparently epidemic charac­ter in many cases; the antecedent febrile condition; its attacking children; the origin from isolated vesicles, which tend to enlarge into blebs and to become pustular, the bleb having a depressed centre, and, it may be, a well-defined, slightly raised, rounded edge; the isolation of the spots; the uniform character of the eruption, and its general and scattered condition; its frequent seat and commencement about the face or head; the circular, flat granular, yellow crusts looking as if stuck on; its contagious nature and inoculability; its frequent following in the wake of vaccination; the absence of pain, and especially troublesome itching at night.

Contagious impetigo may be confounded with eczema; but the history is altogether different, and the isolation, the small scabbed patch, the characters of the crusts, and the facility of cure at once distinguish it. Impetigo sparsa does not arise from a vesiculatiou, but is primarily pustular, made up of aggregated pustules; it does not phlyctenoid; it is not contagious nor inoculable; it does not run a definite course; it is not confined to the young; it is not so amenable to treatment.