Aëtius, copying from Archigenes, thus marks the difference between lepra and its cognate diseases. Lepra differs from leuce and alphos, inasmuch as lepra is distinguished by roughness and a sense of itching, and yet the skin only is affected, and when it is removed, the flesh below is discovered to be sound; but in leuce, the flesh below assumes an unnatural degree of whiteness, while the surface of the part is very smooth, and when rubbed it soon becomes red, especially in those who are readily cured; and alphos is altogether superficial, having the appearance of a scale fastened to the skin. Lepra differs from psora, inasmuch as in psora the substances which appear on the skin are of a furfuraceous nature, while in lepra they resemble the scales of a large fish. He omits the constitutional treatment so judiciously stated by our author, but his local applications are little different. They contain hellebore, sulphur, misy, verdigris, liquid pitch, cantharides, natron, copperas, myrrh, galls, vinegar, &c., mixed in various proportions.
Actuarius states that lepra is next to elephantia in malignity, and that it is distinguished from psora by spreading deeper and having scales of a circular shape like those of fishes; whereas, psora is more superficial, and its scales are furfuraceous and of no determinate shape. Both are attended with asperity of the skin, and itching. Leuce holds the same place to alphos that lepra does to psora, that is to say, leuce is more deep-seated, and affects the colour of the hair, while alphos is more superficial, and the hair is in general unchanged. For all these affections he recommends an application containing copperas, black hellebore, arsenic, and cantharides, mixed with oil, cedar resin, or rose oil.
Psellus states correctly that the scales in leprosy assume a circular shape.
Nonnus marks the distinction between these diseases very accurately. Lepra arises from a corroding humour, and hence scales fall from the surface of the skin, and it is attended with pruritus. But lepra is more deep-seated, and affects the skin circularly; whereas psora is more superficial and variously figured. Leuce and alphos albus and niger, he says, are allied; but leuce is deeper seated, so as to change the colour of the hairs, whereas the alphi are more superficial affections.
Pollux, like most of the others, states that in leuce, when the skin is pricked, it does not bleed, and that the disease is difficult to cure. Alphos and melas, he says, are easily cured.
Although Myrepsus has not described these diseases, he gives prescriptions for various compositions to remove them. The most active ingredients in them are hellebore, natron, sulphur, quicksilver, sal ammoniac, quicklime, bay-berries, &c.
Alexander Aphrodisiensis mentions psora among the contagious diseases, but says that lepra and leuce are not contagious.
Chrysostom alludes to the common opinion that psora is a contagious disease. The poet Æschylus gives a short description of leprosy in his ‘Chöepheræ’ by the name of lichenes. (l. 277.)
Celsus nowhere uses the terms lepra and psora, and therefore there is considerable difficulty in comparing his account of these cutaneous affections with the descriptions of the Greeks. Alphos, melas, and leuce, he describes very intelligibly, connecting them together by the generic term of vitiligo. We shall give his own characteristic description of these diseases:—“Ἄλφος vocatur ubi color albus est, fere subasper, et non continuus, et quædam quasi guttæ dispersæ esse videantur: interdum etiam latius, et cum quibusdum intermissionibus serpit. Μέλας colore ab hoc differt quia niger est et umbræ similis: cætera eadem sunt. Leuce habet quiddam simile alpho, sed magis albida est et altius descendit; in eâque albi pili sunt, et lanugini similes. Priora curationem non deficillimam recipiunt: ultimum vix unquam sanescit.” Another class of cutaneous affections he connects by the generic term of impetigo, and it is to be remarked that they are all squamous diseases, and not pustular, like the complaints to which Drs. Willan and Bateman have applied the term. His second species of impetigo (as Bateman remarks) appears to be the psora of the Greeks:—“Alterum genus pejus est, simile papulæ feræ, sed asperius rubicandiusque, figuras varias habens: squamulæ ex summâ cute discedunt, rosio major est, celerius et latius procedit, certioribusque etiam quam prior temporibus et fit et desinit. Rubra cognominatur.” His third species bears some resemblance to the lepra nigricans of Willan and Bateman:—“Tertia etiamnum deterior est: nam et crassior est et durior, et magis tumet, in summâ cute finditur, et vehementius rodit, ipsa quoque squamosa sed nigra, &c. Nigræ cognomen est.” His account of the fourth species seems to refer to the lepra vulgaris:—“Quartum genus est quod curationem omnino non recipit distans colore: nam sub-albidum est et recenti cicatrici simile: squamulas habet pallidas, quasdam subalbidas, quasdam lenticulæ similes: quibus demptis nonunquam profluit sanguis.” For all these diseases he recommends a composition containing sulphur, natron, and rosin.
Scribonius Largus describes several compositions, “ad lepram, quæ quasi impetigo est cum prurigine cutis,” and for scabies. They contain sulphur, Æthiopian cumin, vinegar, frankincense.