Eye affections due to Lucilia macellaria are very uncommon; the literature relating to the lesions of the eye produced by the larvæ of flies has been collected in Kayser’s[1162] work. In the cases under the observation of Schultz-Zeyden[1163] both the eyes of a female tramp were destroyed, and quantities of larvæ were also found in the nasal fossæ and in the ears.
The Lucilia is found relatively seldom on the cutaneous surface. Henneberg’s[1164] case was that of a neglected girl, aged 20, in whom countless larvæ (L. cæsar) were found in a plica polonica; after the plica polonica had been removed the scalp was found to be covered with a large quantity of ulcers which swarmed with larvæ, large and small. The skin of the trunk was also much macerated and covered with larvæ. Death resulted from sepsis; Westenhöffer[1165] remarks on this case that a lesion of the head from which the patient had suffered previously and the perpetual state of intoxication in which she was had probably given rise to the lodgment of the fly larvæ. Whether the communications made by Munk[1166] of maggots in the mouth relate to Lucilia I do not know. Vesescu,[1167] in one case with extensive ulceration and deep fistulæ in the skin, removed 176 larvæ with the pincette. In Roorda-Smit’s[1168] case there were two ulcers in the neck of a girl, aged 17, and larvæ appeared at their base. After dusting with calomel and the application of a bandage the next day fifty-two dead or half-dead larvæ came to light. Recovery took place. Lesbini,[1169] in the case of an old lady, saw numerous larvæ in an ulcer of the leg she was suffering from. Hector’s[1170] case appears to have been one of myiasis cutanea provoked by Lucilia.
The first exact observations of myiasis cutanea from Sarcophaga magnifica are due to Wohlfahrt,[1171] in whose honour Portschinsky[1172] named this species of fly S. wohlfahrti. Portschinsky ascertained that S. wohlfahrti was not confined to man as its sole host, but that several of our domestic animals, such as cattle, horses, pigs, dogs and geese, were visited. In these animals small wounds serve to entice the flies and to supply them with a suitable site for the deposition of their eggs. The oral armature of the young larvæ renders it easy for them to penetrate not only the mucosa and cutaneous surface but also intact places in the submucous connective tissue. In many localities more than half the herds have proved to be infected by the flies. The fly only frequents open spaces and never enters human dwellings, and is so timid that it approaches man only during sleep; infection, therefore, takes place only out of doors, in summer, in clear, warm weather, and only in such individuals as sleep in the open air. Individuals are most exposed to risk who suffer from catarrhs or inflammations, combined with purulent secretions of the nasal cavity (ozæna), or otorrhœa, or ulcers in any parts of the body accessible to the female fly.
The frequency and intensity of the infection will be in inverse proportion to the advance in civilization of the inhabitants, their idea of cleanliness, their having timely medical aid and the chances of their being rapidly attended to. On that account the majority of cases of myiasis (Sarcophaga) are reported from Russia. The literature of this kind of myiasis nasalis is not very extensive; in addition to Wohlfahrt, Portschinsky and Joseph,[1173] there is a communication by Gerstäcker,[1174] who found fifteen adult larvæ of S. wohlfahrti in the nasal cavity of one man. The larvæ transmitted from Ordruf by Dr. Thomas to Löw,[1175] in Vienna, which were discharged from the nose of a woman, aged 71, suffering from ozæna, were recognized by the well-known dipterologist Braun as belonging to S. wohlfahrti. Among the cases reported by Joseph, one only affected the nose; it was that of a peasant girl, aged 11, who had suffered from ozæna; she had travelled on the open road and had there gone to sleep. Severe symptoms set in and death followed under delirium. In making the post-mortem it was found that the interior of the nose was extensively destroyed by larvæ of S. wohlfahrti. Powell found Sarcophaga larvæ in two persons who had slept in the open air; the larvæ were killed by injections of chloroform and sublimate. Destruction of the eyes by S. wohlfahrti has only been observed in a few cases; it is reported by Cloquet[1176] that, in the case of a ragman who had lain some time in the fields, both eyes were pierced by larvæ. On the outer skin the larvæ of S. wohlfahrti have been found more than once in inflammatory or festering areas. Freund[1177] demonstrated that from a five year old child, which had suffered for some time from an impetiginous eczema of the skin of the head, from two suppurating abscess cavities which extended to the periosteum, which was already affected, twenty-one living larvæ were taken; rapid healing took place under antiseptic bandaging.
The small treatise by Balzer and Schimpff[1178] contains two new observations on myiasis externa; in the one case an ulcer on a man’s foot was full of larvæ, in the other case the head of a woman showed numerous larvæ without the skin of the head being destroyed. Brandt’s[1179] observation is interesting, for he found such larvæ in the gums of a sick person.
The impression which one obtains of the active movement of larvæ on wounds is a strange and at the same time uncanny one. One finds that the larvæ to obtain protection against the drying of the surface of the abscess almost incessantly burrow with their heads, first contracting and then expanding the body, which rises and falls, and keeping the tail upwards. Owing to these movements producing irritation, increase of inflammation may ultimately arise, causing erysipelas and cellulitis.
The treatment of myiasis nasalis caused by Sarcophaga is the same as in myiasis caused by Lucilia, and in the other places where found it is merely a question of the removal of the larvæ and the subsequent proper treatment of the surface of the abscess. In Northern Nigeria Lelean[1180] found Auchmeromyia depressa to be the cause of myiasis externa.[1181]
The occurrence of Oestrid larvæ in a human being is very rare, at least up till now myiasis oestrosa has been very seldom observed in man in Europe. Whilst the hosts of the Muscidæ comprise a considerable number of warm-blooded animals, on which the larvæ develop, each species of the Oestridæ appears, on the other hand, to have a definite host or some definite hosts of the class Mammalia. No species of Oestrid is peculiar to man. Although in America, as well as in Europe, Oestrus hominis was spoken of up to the middle of the last century, no such species exists.
But in both hemispheres, in America much more often than in Europe, Oestrid larvæ have been found in man. In Florida, Mexico, New Granada, Argentina, Brazil, Costa Rica and other districts, and especially where large herds of cattle are kept, myiasis oestrosa has been observed in shepherds, huntsmen and amongst the rural population. The larvæ of Hypoderma bovis, according to the observations of Goudot,[1182] occur as a parasite in man. Poilroux[1183] found larvæ of cavicolous Oestridæ in the nose of a man, aged 55. Amongst the species of warble flies, whose larvæ are parasites in domestic animals and game in Europe, reliable observers have found larvæ of two kinds, Hypoderma bovis and Hypoderma diana, also in man.[1184]
The larvæ of H. bovis have very seldom been observed in the nose. The case quoted by Kirschmann,[1185] which was that of a peasant woman, aged 50, who was suffering from ozæna, and in which violent attacks of sneezing, epistaxis, pain in the forehead, and swelling of the face were observed, is, according to Löw[1186] and Joseph,[1187] not an Oestrid; Muscid larvæ were evidently the cause. By the injection of diluted iron chloride solution seventy-nine larvæ were removed from the nose. In the case reported by Razoux[1188] the species of larva is not definitely known—at least, v. Frantzius[1189] did not consider them Oestrid larvæ. Joseph does not definitely say that Oestrid larvæ were the cause of a case which he quotes. He was sent a number of uninjured larvæ of Oestrus ovis ready to pupate, which were said to have been expelled, during violent sneezing, from the nose of a peasant woman who had suffered for six months from continuous frontal headache and chronic nasal catarrh.