Chapter XLVIII: The Cutaneous System and the Organs of the Special Senses

THE SKIN

_Ringworm infections_ of the skin are so common in the tropics that one should always make an examination for the causative fungi when doubt as to the nature of the lesion exists. Another point is that many hyperaemias, incident to other diseases, seem to furnish a favorable soil for fungi; thus, not infrequently I have found abundant spores and mycelial structures in scrapings from the erythema of the early syphilitic secondaries. Again pruritic lesions may become infected with fungi as the result of scratching, which scratching may not only have this result but furthermore may obscure the dermatological characteristics of the primary disease.

The most expeditious way to examine for fungi is to treat the
scales or hairs with a 10% solution of caustic potash or soda.
Then crush between two slides; heat moderately over the flame and
examine after from 10 to 30 minutes.

A very satisfactory method is to scrape the scales with a small
scalpel, and smear out the material so obtained in a loopful
of white of egg or blood serum on a glass slide. By scraping
vigorously the serum may be obtained from the patient. After the
smear has dried, treat it with alcohol and ether to get rid of
the fat. It may then be stained with Wright’s stain or by Gram’s
method. The ordinary Gram method may be used or the decolorizing
may be done with aniline oil, observing the decolorization under
the low power of the microscope.

_Hanging-block cultures._—To make these, pour melted agar in a
Petri dish and cut from the film so formed sections 1 cm. square.
Place a section on a slide, inoculate and drop on a cover-slip.
Another method is to allow a drop of melted agar, previously
inoculated, to spread over a cover-slip which is then inverted on a
concave slide.

_Prickly heat_ is another condition extremely common in the tropics and the scratching to relieve the itching often leads to infection with fungi or pyogenic cocci.

_Pellagra._—In no other general disease is the skin eruption of such importance in diagnosis and it is practically impossible to make a sure diagnosis of pellagra in the absence of an eruption or the history of an eruption.

The eruption tends to show itself in the spring but may first
appear in the early fall. The lesions resemble a sunburn and burn
instead of itch. The characteristics of the eruption are bilateral
symmetry and sharp delimitation from the sound skin.

As a rule the lesions are dry and atrophic but more rarely, and usually in severe cases, the eruption may be moist and oedematous.

The backs of the hands are the most common sites for the eruption
but frequently there is an extension up the forearm. The neck,
the bridge and alae of the nose, the region back of the ears and
the front of the chest are often involved. In children the feet
and legs are frequently involved. Scrotal eruptions are early
manifestations.

_Leprosy._—In _nodular leprosy_ we have the appearance of macules of greatly varying size and shape with a tendency sooner or later to symmetry. They tend to appear and recur in association with febrile accessions and, even when they have become permanent spots, they show increased redness, infiltration and tension when there is fever.

The color is rather that of a sunburn and may be uniform or the
center may be pale with copper-colored periphery. These spots
appear by preference on face, backs of hands, buttocks, extensor
surfaces of extremities and back. They may mark the location of
later developing nodules. At first they are oily rather than scaly.
We soon note a disappearance of hair within the spot. These spots
soon tend to become anaesthetic. The tubercles of leprosy are
usually of a reddish-brown color.

In _nerve leprosy_ the spots tend to appear on parts of the body usually covered by clothing, as scapular region, shoulders, arms, thighs or buttocks. The outline is ovoid rather than round and the spots may at first be hyperaesthetic rather than anaesthetic, as they later tend to become.

In circinate eruptions we often note a pale center with
brownish-red borders. These borders may be hyperaesthetic while the
centers show anesthesia. Bilateral symmetry is more common in this
than in nodular leprosy.

Besides the spots nerve leprosy may show blister-like lesions on
backs of hands and feet especially in the region of the knuckles.
Ulceration may follow.

_Malaria._—The most common cutaneous manifestation of malaria is herpes labialis. This is more common in benign types than in malignant ones. Urticaria is next in frequency. Malaria has seemed to be the cause of certain cases of purpura simplex.

In attributing skin manifestations to malaria one must always have
in mind the scarlatiniform, urticarial and erythematous rashes due
to quinine used in treatment.

_Urticarial Fever._—In Japanese schistosomiasis the earliest symptoms are the urticarial rash and fever.

_Plague._—Rarely cases of bubonic plague may show a small vesicle marking the site of the flea bite. Areas of necrosis of the skin, which are really sloughing patches, and incorrectly designated “carbuncles,” may be noted, especially over the site of the buboes.

In the later stages haemorrhages into the skin (petechiae) are
common.

_Trypanosomiasis._—Patchy areas of erythema are often noted in Europeans affected with this disease. These are frequently circinate with fading in the center and tend to appear on the trunk.

In natives a dry skin is more often noted.

_Rat Bite Disease._—An eruption of purplish spots may accompany the fever. There is a resemblance to erythema multiforme.

_Dengue._—The true eruption of dengue is the one that appears about the fourth or fifth day as a measles-like eruption, starting about wrists or ankles.

_Kala-azar._—There is a darkening of the colored skin of the natives suffering from this disease and it is to this feature that the disease owes its name.

In Europeans the appearance is more that one sees in old malarial
cachectics, an earthy gray color. The characteristics of cutaneous
leishmaniasis are discussed under that heading.

_Typhus Fever._—Gangrene is particularly a feature of _spotted fever of the Rocky Mountains_ and _typhus fever_, chiefly of the scrotum and prepuce with the former and of the extremities in the latter.

The distinctions of the eruptions of these two diseases and of
_tsutsugamushi_ are given on page 445.

_Tsutsugamushi._—A small necrotic ulcer with a dusky red areola, often located in the armpits or region of the genitals, marks the site of the bite of the infecting mite. From it a lymphangitis leads to the swollen glands. About the seventh day a macular eruption, which never becomes petechial, appears on face, then on trunk and extremities.

_Tularaemia._—There is often a local lesion at the site of the bite of the infecting _Chrysops_. The tributary glands are swollen.

In _ancylostomiasis_ the site of entrance of the infecting stage of the larvae is marked by a dermatitis—ground itch.

Tibial ulcers are also features of this disease.

In _filariasis_ we not only have the bleb-like lesion of guinea worm infection but also the calabar swellings of _Filaria loa_. Elephantiasis and lymph scrotum are the best known skin manifestations of _F. bancrofti_, but there may also be present filarial abscesses. The tumors of _O. volvulus_ are most often on sides of chest, are quite superficial with the skin freely movable over them.

_Epidemic Dropsy._—It is a question, whether such a disease as
epidemic dropsy is distinct from beriberi. An erythematous eruption
about the face and a macular one of the trunk and extremities are
usually stated to be features of this disease.

_Juxta-articular Nodes._—This is a condition in which small tumors form under the skin especially in the region of the elbows. These bean to walnut-sized tumors of the subcutaneous tissues may also be noted about the knees. A fungus has been reported as cause but the present view is that the cause is unknown.

_Oriental Sore._—This form of cutaneous leishmaniasis is especially common in Asiatic Turkey and Northern Africa. It begins as a small papule which eventually ulcerates, the sore scabbing over from time to time and again breaking down. Indolent granulations and a very protracted course are rather characteristic features.

_American Leishmaniasis._—The most important point of differentiation of this form of leishmaniasis from oriental sore is the occurrence of ulcerating lesions of the mucous membranes of mouth or nose subsequent to the appearance of the oriental sore-like lesions on forearm, legs, trunk, or rarely the face. In Peru the term _uta_ more properly belongs to the skin affections while _espundia_ is the designation applied to the lesions of the mucous membranes. It may be stated that a form of oriental sore has been reported from Greece where mucous membrane ulcerations have been associated with the ordinary skin-type lesion.

_Dermal Leishmanoid._—Brahmachari has described a form of generalized cutaneous leishmaniasis, bearing a superficial resemblance to leprosy, which may develop a variable number of months after apparent cure of kala-azar by antimony. Having found leishmania bodies in the lesions, he conjectured that some of the parasites survive the action of the drug, but with their virulence so attenuated that they can give rise only to a milder disease, a variant of cutaneous leishmaniasis, to which he gives the name “dermal leishmanoid.”

NOTE.—The special tropical diseases of the skin are discussed
under their respective headings.

THE EYE

_Glaucoma._—According to Elliott glaucoma is very much more common in the East than in Europe. He states that simple chronic glaucoma is extraordinarily common in India. Often the only symptoms are retraction of the field, cupping of the disc and at a later stage impairment of the central visual acuity. He notes that the advancement of the disease is often as unobtrusive as it is relentless. These patients often only present themselves at the clinic in the late stages of the disease; thus at the Madras hospital the vision was only that of hand perception, or less, in 40% of cases.

_Cataract._—The general impression is that cataract is more frequent in the tropical regions than in Europe and as bearing out this view Elliott notes that cataract among those Europeans who have served in India seems more frequent than among those who have remained in England. Cataract is also more common in the southern part of China than in the northern portion.

_Lachrymal Obstruction._—Elliott notes the extreme frequency of this condition in India, and states that in the Madras Ophthalmic Hospital 125 operations for excision of one or both lachrymal sacs were performed in 1907.

_Trachoma._—There are certain tropical countries where trachoma is a disease of the greatest importance. Thus in China its prevalence is great, as is also true of India, Egypt and Japan.

Outside of imported cases it is very prevalent in many parts of the
United States.

In this disease there is hypertrophy of the conjunctiva, granule formation and subsequent cicatricial changes. Pannus and corneal ulcerations are frequent complications.

The disease is contagious through transfer of the secretion by
hands or flies. It is usually considered as caused by the so-called
trachoma bodies or cell inclusions, which are best brought out by
Giemsa staining. The trachoma granules are yellowish, translucent
bodies set in the reddened conjunctiva.

_Leprosy._—The eye is more frequently involved in nodular than in nerve leprosy. In the former we have infiltration of the conjunctiva which may extend to the cornea.

The leprous nodules invading the palpebral conjunctiva tend to
ulcerate and bring about various distortions of the eyelids,
producing ectropion. Iritis, irido-cyclitis and irido-choroiditis
are less frequent than conjunctivitis and keratitis. The optic
nerve and the retina are only rarely involved.

In nerve leprosy the eye changes are chiefly connected with the lesions of the fifth and facial nerves. Ptosis and paralytic ectropion occur with frequency.

Ophthalmia and corneal ulcerations may lead to total destruction of
the eye. The cornea may be anaesthetic. Paralysis of one or more
ocular muscles may cause squint or diplopia.

_Malaria._—It is questionable whether the forms of conjunctivitis and keratitis at times reported as due to malarial infection are not rather of other origin.

Iritis is rarely a complication of malaria.

Retinal haemorrhages may occur in malarial cachexia and cerebral types of pernicious malaria.

Another rare malarial complication is amblyopia. In this there is
an optic neuritis with grayish-red disc and the loss of vision is
not complete, while in quinine amblyopia the disc is white and the
vision completely lost for a time.

_Filariasis._—In that filarial infection caused by _Loa loa_, at one time designated _Filaria oculi_, there seems a special tendency for the adult worms to wander to the subcutaneous tissues in the neighborhood of the eyes or under the palpebral or ocular conjunctivae. When moving under the conjunctiva the worms cause marked irritation and at times pain.

There may be considerable swelling so that the patient cannot for a
time see out of the invaded eye. It has been stated that the worms
may enter the anterior chamber of the eye but this is questionable.

It is believed that lesions of the cornea and iris may result from
the migrations through the body of the _Onchocerca volvulus_.

_Trypanosomiasis._—Eye lesions are quite frequent in this disease these being keratitis, irido-cyclitis or conjunctivitis.

Oedema about the eyes is of importance in diagnosis. Eye lesions
seem more common in Rhodesian trypanosomiasis. The atoxyl treatment
of the disease may cause optic neuritis and blindness.

_Tick Fever._—In the relapsing fever of South Africa iritis has been noted as occasionally occurring.

_Yellow Fever._—In the period of onset a feature of the so-called “facies” of the disease is marked injection of the conjunctivae with sensitiveness to the light.

Rush likened it to the eye of a wild animal as contrasted with
the less ferocious eye of bilious remittent fever which more
resembled that of a domesticated animal. About the third day the
earliest manifestation of jaundice presents itself in the ocular
conjunctivae.

_Ancylostomiasis._—Retinal haemorrhages may occur with marked hookworm anaemia. Stiles notes a fixed stare in hookworm cases, the eye itself somewhat resembling the eye of a fish.

Among other diseases showing ocular manifestations may be mentioned
one associated with fibrous nodules in the upper lid due to a
larval dibothriocephalid, _Sparganum mansoni_.

_Bacillary Dysentery._—Quite a number of cases have recently been reported where along with an arthritic complication there has been conjunctivitis. In 6 cases of dysenteric conjunctivitis, Maxwell noted that 4 cases had arthritis and 3 of the latter showed anterior uveitis. The conjunctivitis lasted about a week. Relapses seem liable to occur. In none of the cases has there been recovered from the conjunctival secretion the organism of dysentery.

_Cholera._—As a result of the loss of all body fluids the lachrymal secretion is scanty or absent and we have various conjunctival and corneal troubles unless the eye is frequently irrigated with normal saline. Vitreous opacities and cataract may follow cholera.

_Beriberi._—In this disease there have been reported the following eye complications: (1) retrobulbar neuritis; (2) paralyses of the muscles of the eye and (3) decreased sensibility of the cornea and conjunctiva.

_Night Blindness and Xerophthalmia._—Both of these conditions are quite common in certain parts of the tropics and the view that the heat of the tropics and the tropical sunlight were potent factors had precedence until our study of vitamine requirements showed the etiology to rest in deficiency of fat soluble A. It is now known that cod-liver oil is particularly rich in this vitamine and that in this agent we have our best preventive and curative agent for these eye conditions. It is well known that rats fed on a diet deficient in fat soluble A develop xerophthalmia.

Night blindness (nyctalopia) is best known among the crews of
sailing ships, especially when becalmed in tropical waters, and
some influence of sunlight was considered the cause, but we now
know that it is among such personnel that ship beriberi and scurvy
are prone to occur by reason of deficiencies in water soluble B and
the antiscorbutic vitamines. In such a dietary fat soluble A would
also probably be lacking.

In those parts of the tropics where famine conditions are common
both night blindness and xerophthalmia are frequent in young
children, not necessarily associated but frequently combined.

In a mild case of xerophthalmia there is a dry area of triangular
shape extending from either side of the cornea and covered with a
fine, whitish foam. In bad cases the whole eye may be dry, wrinkled
and opaque and eventually the cornea may slough away and bring
about destruction of the eye. There is very little pain attending
this frightful condition.

Elliot notes that from earliest times it was the custom in China
to treat these conditions with extracts of liver. We now know
that liver and kidneys are glandular organs rich in fat soluble A
although not so rich in this vitamine as cod-liver oil.

_Typhus fever._—There may be a rapid development of cataract of the soft variety, particularly in young patients. Ocular palsies, especially of the third and sixth nerves may occur during the febrile period. Corneal ulcers are not uncommon during convalescence and may be severe and very painful, often accompanied by conjunctivitis and iritis.

THE EAR

_Aural Myiasis._—While the larva of _Chrysomyia macellaria_, known as the “screw worm,” is the one most frequently reported from the external auditory canal, yet many such cases have been connected with the larvae of _Sarcophaga carnaria_, _Calliphora vomitoria_ and _Anthomyia pluvialis_. These larvae are usually deposited in the auditory canals of those with otorrhoea.

The symptoms are intense earache, giddiness and possibly
convulsions. The larvae tend to perforate the tympanic membrane.
Instillations of 10% chloroform in milk or the use of oils kill the
larvae.

In the stuporous states of _plague_ and _typhus fever_ there often appears to be a state of deafness.

One must always keep in mind the ringing of the ears indicative
of the physiological action of quinine. Permanent deafness may be
produced by the long continued use of quinine.

In leprosy the lobes of the ears are special sites of preference for the nodules and I always palpate the lobes where the nodules are not distinctly visible.

THE NOSE

_Nasal Myiasis._—In cases of ozaena certain flies appear to be attracted and to deposit their eggs at the nasal orifices. The larvae developing from the eggs of _Chrysomyia macellaria_, a fly common in tropical America, are known as “screw-worms” and cause frightful destruction of the nasal structures.

They may bore into the adjacent sinuses. Marked frontal headache
and a purulent or bloody discharge are symptoms. Great swelling of
the nasal structures precedes the destruction of the cartilaginous
and bony tissues.

_Leprosy._—The nasal mucosa is apt to be the seat of leprous nodules. Those located on the septum may ulcerate and material from these ulcers show abundant leprosy bacilli. Alternations of dryness and hypersecretion of the Schneiderian membrane are among the early manifestations of the disease.

=Epistaxis.=—This is a feature of the early stages of _leprosy_ often associated with rhinitis, in particular the alternation of coryza-like conditions with others characterized by dryness of the nasal mucosa.

There is also a peculiar nasal tone to the voice of lepers.

In _yellow fever_ and _plague_ epistaxis is often the first sign of the degeneration of the endothelial linings of the capillaries.

_Gangosa._—A disease of certain islands of the Pacific, especially
Guam, characterized by naso-pharyngeal lesions and a nasal voice,
is known as _gangosa_.

In _goundou_ we have exostoses from the nasal processes of the superior maxillary bones.