446 DISEASES OF THE SKIN. 



as by these means the extensive accumulation of detached epiderm 

 may be prevented. 



CHAPTER II. 



DIFFUSE HYPERTROPHY OF THE SKIN AND SUBCUTANEOUS CONNEC 

 TTVE TISSUE PACHYDERMIA ELEPHANTIASIS ARABUM. 



ETIOLOGY. Repeated inflammation of the skin, and especially re 

 peated and permanent obstruction of the veins or lymphatics of a part, 

 sometimes lead to enormous growth of the connective tissue of the 

 skin, subcutaneous and intermuscular substance, and even of the perios- 

 teum of the bones of the affected part. This condition is called/>acAy- 

 dermia,) or, from the clumsy, deformed appearance of the limb attacked, 

 it is also called elephantiasis arabum. This disease has nothing in 

 common with the elephantiasis grcecorum, or leprosy (lepra, Spedalr 

 skhed). We do not know the reason why it is that a case of repeated 

 dermatitis, or phlebitis and primary thrombosis, or of obliteration of a 

 vein or lymphatic, only now and then terminates in pachydermia, and 

 why it does not always occur. It is also quite strange that this dis- 

 ease should be much more common in certain countries, especially in 

 the torrid zone (Barbadoes leg), than it is with us. 



ANATOMICAL APPEARANCES. The most usual seat of the disease 

 is upon the leg, which undergoes more or less irregular enlargement, 

 and attains more than two or three times its normal size. The skin 

 is immovable, and, when the papillary layer also takes part in the hy- 

 pertrophy, it is covered with scaly crusts. The tissue of the skin, and 

 of the adipose layer below it, is converted into a dense firm mass, re- 

 sembling bacon, whose microscopic elements consist of connective-tis- 

 sue cells of different stages of development. The muscles are atro- 

 phied and in a state of fatty degeneration, owing to a want of exercise, 

 and to the pressure to which they are subjected by their surrounding 

 connective tissue, which is likewise involved in the thickening. The 

 veins and lymphatics are often obliterated, and there is frequently a 

 varicose enlargement of them below the point of obstruction. The 

 anatomical appearances are quite similar when the disease attacks the 

 upper extremity, the scrotum, the penis, or the labia majora. 



SYMPTOMS AND COURSE. The first symptom of the disease is 

 either an erysipelatous inflammation of the skin, or else a lymphangitis 

 or a phlebitis. Some authorities state that the local disease is often 

 preceded by violent fever. This cannot be regarded as at all singular, 

 as in other inflammations the febrile disturbance is generally most 

 severe at the commencement of the attack, and attracts attention be 



