REVIEW — TKOPICAL MEDICINE, ETC. 183 



The initial rashes are then considered, morbilliform, scarlatiniform and haemorrhagic types receiving mention Small-pox 



and their diagnosis from those of measles (especially the papular forms), scarlet fever, and from septic rashes conliniiM 



considered. The occurrence of small-po.K without a rash is also mentioned. After the appearance of the rash 

 which is described at all its stages, the diagnosis has to be made from : — 



In all stages ; chicken-pox, acne, syphilis, drug eruptions, glanders, scabies, lupus, especially of the face. 



In the papular stage : prodormal rash of measles, erythema nodosum, lichen planus. 



In the vesicular and pustular stages : herpes, erythema iris, and erythema bullosum. 



In the pustular stage : impetigo, and pustular scarlet fever. 



As regards chicken-pox, he notes that there is a type, chiefly found in adults, in which 

 the face distribution may be nearly, if not equally, as intense as that on the trunk. The 

 points distinguishing varicella from variola have been tabulated under the heading chicken- 

 pox, and Thomas, after dealing with this question, points out that the greater depth of the 

 initial skin lesion in small-pox explains : — 



(1) the shotty character of the rash ; (2) the pearly-yellow contents of the vesicle, the colour being due to the 

 thicker epithelial covering ; (3) the hardness and hemispherical surface of the vesicle ; (4) the absence of the 

 crenated edge in the vesicle. This is possibly damped out by the thicker layer of epithelium, iust as the 

 several layers of an ouiou hide the irregularities at the core ; (5) the absence of early cupped scabs owing to 

 the difficulty of rupture ; (6) the pitting ; (7) the thickness of the crusts ; (8) the presence of " seeds " in the 

 palms and soles ; (9) possibly the umbilication and the formation of septa. 



The superficial position of the lesion in chicken-po.x explains : (1) the moderately soft character of the 

 rash ; (2) the clear transparent, almost colourless, contents of the vesicle, due to the very thin epithelial 

 covering ; (3) the soft and sometimes spherical or ellipsoidal surface of the vesicle ; (4) presence of crenation 

 or puckering in the vesicle ; (5) early cupped scabs ; (6) the absence of pitting, save in severe eases ; (7) the 

 thinness of the crusts ; (8) the absence of " seeds " in palms- and soles. 



He notes that there is no one characteristic sign on which absolute reliance can be 

 placed, and that it is often very difficult to distinguish moderately severe chicken-pox from 

 mild small-pox. The rule is to consider whether the affection is trivial or grave. In the 

 latter, vaccinate and treat as small-pox. In the former, vaccinate also if doubt persist and 

 treat as chicken-pox. 



In the Sudan the diagnosis from syphilis may give rise to trouble, and the following 

 points will serve to distinguish the two diseases : — 



History of exposure may be obtained in one or the other, and in syphilis the original chancre, its scar, 

 or the usual secondaries may be recognised. In the male, where there is no chancre or its scar, the urethra 

 should be examined for its presence. 



Mode, of Onset. — In syphilis, slow, insidious, the fever is not high, nor are the constitutional signs urgent 

 or severe. There is no initial chill, no backache ; the headache, if present, is not severe. The patient is able 

 to go about his daily work ; he does not lie up. The temperature does not remit with the appearance of 

 the rash — there is no feeling of hein aise. In small-pox there is a sudden onset by chill, early high 

 temperature, severe backache and headache, often vomiting. The patient lies up at home and stops work. 



Rash. — In syphilis this takes many days to appear; in small-pox twenty-four to forty-eight hours. In 

 syphilis there is no remission of temperature, no establishment of bieii aise. The distribution of the syphilitic 

 rash may be like, or unlike, that of small-pox. It is generally more copious on the trunk than on the face, 

 and is rarely found in the soles and feet. The rash of syphilis is polymorphic, and may exist as papule 

 pustules small and large, or vesicle concurrently. The pustules and vesicles of syphilis are usually conical, 

 with deep subjacent ulceration ; they are not flattened hemispheres as in small-pox. 



Progress. — The regular sequence from papule to vesicle to pustule, with the proper time intervals, is 

 present in small-pox, absent in syphilis. In the latter the development of the lesions is most irregular and 

 slow. 



Thomas asks, " Is Vaccination of any value as an aid to diagnosis " ? and replies in the 

 negative, going on to remark ; — 



There are rare cases on record in which patients efficiently vaccinated have subsequently 

 passed through undoubted attacks of modified small-pox within a few months. 



The possible consequences of even one unrecognised case of small-pox set free are so 

 appalling that any uncertain criterion must be ruthlessly discarded. On the other hand, 

 I have never seen a case of small-pox which could be successfully vaccinated within two 

 years of the attack. We want to know the interval between a case of small-pox and the 

 possible subsequent successful vaccination. Second attacks of small-pox are known, so 

 that it is quite legitimate to assume that small-pox patients may be at some later period 

 successfully vaccinated. 



It has been stated that if vaccination be performed within three or even four days of 

 exposure to small-pox, the threatened attack will in all probability be aborted. Mora definite 

 information is required too on this head, so that the possibility of successful vaccination may 



