ARTERIAL HYPER/EMIA The arterial hypenernia of congestion is caused by an increased blood supply to the arteries, whether by augmented pressure or ished resistance of the circulation. The best known form of this irmia is erythema pudoris, produced under the influence of shame, joy, etc. It occurs chiefly in children and disappears with advancing age. Soon after birth infants exhibit erythema neonatorum. It increases up to the middle of the first week of life and generally disappears with out leaving a trace. Whether there is any connection between this affection of the vessels and the icterus which sometime,7, appears in its wake, is an open question.
In digestive disorders and in the period of dentition the so-called inlantile erythema makes its appearance, sometimes in spots, some times spreading diffusely over the body; it is frequently accompanied by light fever.
In 1S99, Sticker and Schmidt described an erythema infeetiositm occurring epidemically in children, commencing symmetrically on the eheeks and spreading first to the extremities and then to the trunk. There are flat pimples, sometimes red and sligthly raised, burning, spots, forming figures like geographical charts, and healing froni the centre. They are often accompanied by dysphagia, coryza and light fever. The affection heals spontaneously in four to five (lays and is to be regarded as absolutely benign. It has also been clescribed in 1904 by Placht under the sante name (or megalerythema) as being a small family epidemic. Escherich classifies the affection among roseola.
To this category also belongs erythema raceinieum (roseola vac einica) and erythema rariolasum (described in detail at another place). The former appears either on the second day or only after 7 or S days (and later still) after vaccination, either as a by-effect of the vaccine or poison or later in consequence of resorption of the ulcerous vaccine masses. I have personally seen such a case develop fourteen days after vaccination.
Erythema variolosum generally appears on the second or third day of illness.
The other forms designated as erythema, especially erythema from the effects of heat or counterirritants, erythema from the effects of light, are no actual erythemata, brit only the prodromal stages of a dermatitis, the actual inflammation of the skin. When in the treatment of erythema the irritation is absent, the affection will not advance beyond erythema and the dermatitis will not appear. The best known is erythema colorant (sun burn or glacier burn), which is caused principally by the influence of the ultra-violet rays of the spectrum; among the forms of erythema from counterirritants there is chiefly erythema following the use of arnica, mustard plasters, etc. Under treatment by the X-rays, erythema and superficial dermatitis develop which under certain conditions may continue for a long time.