Psoriatic syphilides

Nozo asserts that psoriatic syphi-lides always indicate the presence of a grave variety of syphilis and that they occur most commonly in cachectic subjects. In some cases they may appear as late manifestations of the disease; and their development is favored by old age, alcoholism, congenital or acquired dryness of the skin, and perhaps, also, by gout. Cases occur concerning which even the most expert diagnostician may be in doubt as to whether the eruption is the ordinary psoriasis or a specific eruption.

When psoriasis is in progress of cure, the scales lessen and the reddened elevated surface beneath comes more prominently into view; but this diminishes gradually till the eruption disappears, leaving oftentimes no trace of its former presence behind. It may leave, however, pigmentary stains, the result of the congestion. It is in the disappearance of patches of psoriasis that the centre rapidly clear, and the ringed form or psoriasis circinata, or the lepra of old authors is produced.