SUPPLEMENT 711 



has rest from it for a time. A wheal develops around the haemor- 

 rhagic area of the bitten spot and itches severely. The itching goes 

 on until the eruption is scratched all over. This is followed by crust 

 formation. When many parasites are present the itching reflexes 

 become more severe, and the patients scratch themselves considerably 

 and make long marks at those places where the Pediculi have been. 

 The localization of the scratching effects is characteristic, correspond- 

 ing with folds between portions of clothing (regions between the 

 shoulder-blades, wrist and neck). If the condition lasts for a month, 

 the scratching effects extend over the whole body, and secondary 

 efflorescences become associated with it, such as pustules, ulcers and 

 eczemas. Intermediate between this we find cicatrices and pigmenta- 

 tion, the latter under certain circumstances extending over the whole 

 body. Sulla, Herod, Cardinal Dupet, Philip II, and others are said 

 to have died from louse disease. That even at present many human 

 beings are exposed to the danger of being devoured by lice is a fact 

 that we have had the opportunity of observing on several occasions. 

 Only to record one instance, a man, aged 65, was received into our 

 clinic some time ago in an absolutely neglected condition (he had 

 been staying for some weeks in a stable, lying on a wretched bed). 

 The whole of the surface of his body was covered with countless 

 furuncles, of greater and less size, which had partly become changed 

 into undermined ulcers. Over the ulcers and beneath their undermined 

 edges Pediculi were swarming. 



Phthirius inguinalis (Pedicultts pitbis) (Crab Louse). 



The transmission of these parasites generally takes place during 

 coitus, and therefore they especially occur in the pubes. It is possible 

 also that transmission is effected through dirty clothes and bed-linen 

 and privy seats. 1 Starting from the pubes the animals crawl out over 

 the other parts of the body provided with hairs to the abdominal 

 wall and the thorax (so far as these parts are furnished with thick 

 hair) to the arm-pits, the beard, the eyebrows ; not, however, to the 

 hair of the head, or rarely so ; among our numerous cases we have 

 never met with an example of the crab louse attacking the hair of 

 the head. 



The irritation produced by the crab louse is extraordinarily severe, 

 especially during the night, as the warmth of the bed incites the lice 

 to active sucking. In consequence of the violent scratching indulged 



1 [A case of infection through a dirty station privy in Switzerland came to my knowledge 

 in 1899, and numbers of pediculi were found there. F. V. T.] 



