The definition of rosacea is not as easy as one would suppose. The essential characteristics are, first, the location in the midportion of the face, the so-called flush area; second, the chronicity of the disease, and, third, erythemas of different types. In addition to these one may find thickening of the skin, telangiectases, papules, pustules, crusts, scars, seborrhea, and, in cases complicated with acne, comedones. For the patient rosacea is a serious problem chiefly on account of the psychic disturbance caused by the disfigurement. Any physician who has treated many cases knows how unsatisfactory are the therapeutic results and how frequently one sees recurrences in apparently cured cases. The reason for this is probably that most treatment is directed at symptoms rather than at the cause of the disease.
A clinical experience gave impetus to our present study. A woman with a pustular eruption of the face, of several years'
FEIT H, LASZLO EA, VERO F. ROSACEA INTERPRETED AS A BACTERID FROM FOCAL INFECTION. JAMA. 1935;105(22):1738–1741. doi:10.1001/jama.1935.02760480008003