LOUSE BORNE DISEASES 287 



URTICARIA, — The attack of the body louse, popularly called 

 "cootie," produces minute haemorrhagic spots which are accompanied by 

 more or less urticaria, the itching leading to scratching. The bites are 

 principally distributed over the neck, back and abdomen. Peacock found 

 louse rash distressingly common among the British troops. 



MELANODERMIA. — In tramps, chronic drunkards, and vagabonds 

 who have harbored lice for many years, the skin over the areas most fre- 

 quently bitten becomes rough, hardened, and deeply pigmented, a condi- 

 tion known as morbus errorum or vagabond's disease. This skin pigmen- 

 tation, also called melanodermia, may extend to the mucous membranes, 

 being visible in the mouth and is sometimes confused with Addison's 

 disease (Nuttall 1917). 



ECZEMA. — Frequently the attack of the lice causes an eczematous 

 inflammation of the skin, with exudation of lymph. 



PYODERMIA.— Nuttall records PUSTULAR DERMATITIS and 

 PRURIGO SENILIS due to louse bite. Smith (1918) considers the 

 pyodermia (ecthyma, etc.) caused by the body louse a more serious dis- 

 abling skin disease than scabies. Various authors have claimed that 

 the lice sometimes burrow under the epidermis forming so-called "covered 

 louse-ulcers," which on opening liberate many lice. 



TOXEMIA. — Moore cites instances of intoxication of the system 

 from louse injected toxins. 



^. Types of Pediculosis Capitis 



Head lice may produce urticaria, eczema and pyodermia, of which the 

 most important type is mentioned in the next paragraph. Pinkus states 

 that the inflammation of the scalp may lead to falling out of the hair. 



PLICA POLONICA. — As results of eczema or pustular dermatitis of 

 the scalp the exudations of the skin lead to formation of scabs and 

 crusts in the hair especially at the nape of the neck, and this condition 

 has been called plica polonica because it is so frequently observed among 

 the poor Jewish population of Poland. (Nuttall 1917.) 



3. Types of Phthiriasis 



The pubic iice occur in the pubic regions principally, but are also 

 found in the axillae, eyebrows, and other parts of the body. They 

 cause great discomfort unless the host is hardened to them. (Nuttall 

 1918.) 



PRURITUS. — The attack of this louse causes a pruritus which can 

 be violent and leads to much scratching day and night. It is thought that 

 the itching is primarily caused by the toxic saliva of the louse. 



