1972 



DISEASES OF CONNECTIVE TISSUES 



LOIASIS. 



Definition. — Loiasis is a subcutaneous and subconjunctival 



filariasis caused hy Loa loa (Guiyot, 1778). 



Remarks. — Loa loa, which is carried by a species of Chrysops, a.- 

 discovered by Leiper, has frequently been noticed in the ocular and 

 palpebral conjunctivae crossing the bridge of the nose, in the skin 

 over the ster no-mast oid muscle, or that of the scalp, the fingers, the 

 penis, etc., and much more rarely in the anterior chamber of the 

 eye, though accounts of its presence in the vitreous humour require 

 confirmation. For description of the worm see p. 645. 



Climatology. — -The geographical distribution of the worm is con- 

 fined to the West Coast of Africa from Sierra Leone to Benguela, 

 but is most particularly Old Calabar, the Cameroons, and the 

 Ogome River. It penetrates some six hundred miles or more into 

 the interior of Africa. 



Symptomatology. — In our experience it usually causes but little 

 disturbance, but at times, when in the conjunctiva, it is associated 

 with piercing and lancinating pains, uncertain vision, and swelling 

 of the eyelids. It is probably the cause of the Calabar swellings 

 mentioned below. 



Treatment.— It can be removed by an incision and careful traction. 

 Hot fomentations, as noted by Elliott, cause the worm to come to 

 the surface. 



CALABAR SWELLINGS. 



Synonyms. — Kamerungeschwiilste, Tropical swellings, Ndi-tot = 

 swelling (Calabar). 



D3finition. — Calabar swellings are smooth, temporary, slightly 

 raised tumours on the head, arms, hands, ankles, and feet, probably 

 caused by the presence of Loa loa (Guiyot, 1778), and possibly 

 other species of filaria or allied genera in the subcutaneous tissue. 



History. — ^For many years it has been known that peculiar swellings 

 occurred in the people living in Old Calabar, and in due course ac- 

 counts appeared in works of travels in West Africa, but it was not till 

 1895 that Argyll Robertson described them as a distinct disease, using 

 their popular nomenclature. In subsequent years he published several 

 accounts of his cases. In 1898 Plehn drew attention to the complaint, 

 and in 1899 Thompstone published an account of a case, while 

 Habershon and Kerr in 1904, Wurtz and Clerc and Stephens in 1905, 

 and Ward in 1906, have all added to the literature of the subject. 



The paper by Ward is, however, of especial interest, as it deals 

 fully with the history of the disease. 



Climatology. — The disease is only known on the West Coast of 

 Africa, particularly in the regions of Southern Nigeria and the 

 Cameroons. We have seen, though rarely, a similar condition in 

 Ceylon, where the existence of Loa loa has not been reported. 



Etiology and Pathology. — There is a consensus of opinion that in 

 some way these swellings are caused by Loa loa Cobbold, 1864, 

 but this has never been definitely proved. 



