Complete Text (Part 5)

to be seen in their full development only during life and are described in the test books of dermatology. We shall dis- cuss in detail only those modifications which are, or may be, connected with disease of the internal organs, or which have special pathologico-anatomical interest. (a.) GENERAL MORBID CONDITIONS. 1. On our way from without inwards we first come to cer- tain changes in the epidermis. The first of them to be mentioned is abnormal separation or detachment of the upper horny layers. While from healthy skin the older layers of the epidermis are gradually and insensibly cast off, the epidermis is often cast off in larger or smaller coherent masses, not only as a result but also as a part of many cuta- neous affections. In psoriasis and pityriasis versicolor, des- quamation takes place in small scales, which in the latter disease are distinguished by their brownish shade ; rather larger masses are shed after many of the acute exanthemata — measles, for example ; finally, if the epidermis be detach- able in large strips, or from a whole finger or hand, scarla- tina is pretty clearly indicated. The desquamation from an otherwise healthy skin should not be confounded with the post-mortem detachment of epidermis over inflamed surfaces as in erysipelas, or with the same condition resulting from inflammation of the subcutaneous cellular tissue (phlegmon), in which cases the surface from which the epidermis has be- come separated is always moist and usually reddened or of a dirty greenish color. A like condition may be met with, not SKIN AND SUBCUTANEOUS TISSUE. 17 dependent on inflammation but on decomposition. In this case other evidences of decomposition will also be present and prevent our falling into error. The epidermis may be separated from the true skin by- circumscribed collections of fluid (blisters), which are gene- rally of a pale, dirty-red color, when the result of decompo- sition. The same appearance may be met with in fresh bodies, provided that decomposition had begun during life, — over spots of gangrene, for example. An eruption of small vesicles, attended with but slight ele- vation of the epidermis, is not an accidental complication, but rather an actual morbid condition. According to the character of the contents, a distinction is drawn between vesicles or hullce., both of which contain a clear watery fluid, and differ only in size, and pustules., which contain pus. The latter may be a later stage of the former, in which case both are found associated. 2. The integrity of the deeper layers of the skin, the cutis proper, depends on that of the epidermis. If the latter be detached from any cause, the cutis dries by evaporation into a stiff brown parchment-like substance. Whether this dry- ing up involves only the upper layers of the cutis, or its whole thickness, is readily seen on cutting into it. Great distention or pressure may cause atrophy of the cutis ; hyper- trophy, however, is more common. If such hypertrophy take the form of hard elevations from the size of a hempseed to that of a bean, they are called papules.^ and may be due to inflammation, haemorrhage, morbid growths, etc. Discolora- tion of the skin has been already discussed. (6) SPECIAL MOKBID CONDITIONS. 1. Haemorrhage into the skin may be divided according to its size and form into petechice, small round effusions of blood, viMces, small longitudinal effusions, and ecchymoses, larger effusions. The latter are generally of traumatic origin, and are less interesting than the smaller effusions, which are usu- ally associated with the acute exanthemata, purpura hamor- 18 DIAGNOSIS IN PATHOLOGICAL ANATOMY. rhagica, etc. The most minute form of all occurs in ulcera- tive endocarditis, as a result of embolism of the cutaneous arteries, and is associated with similar haemorrhages into the conjunctiva and buccal mucous membrane, as well as with minute abscesses. To these latter we shall return later. 2. Inflammation is met with ; — (a.) In small isolated spots more or less numerous. The affections which come under this head concern rather the dermatologist, and hence will receive but little attention here. Psoriasis represents squamous inflammation and is characterized by the detachment of the epidermis in small scales. Among the vesicular inflammations are miliaria (su- daviina'), characterized by multiple minute vesicles, either perfectly transparent like dew-drops, or whitish or reddish, presenting no trace of inflammatory action at their circum- ference,— and herpes (facial, progenital, zoster). In the latter affection the vesicles likewise contain clear fluid, but show evidences of inflammation at their base, and, if rup- tured, may be either scabbed over or remain as raw surfaces. The first stage of eczema (eczema vesiculosum) is also char- acterized by clear vesicles whose base is much inflamed, and swollen by collateral oedema : in their later stages they may become pustules or form scales and crusts. Pemphigus, with bullae containing either serum alone or a mixture of serum and pus, comes also under this head. In the form of pem- phigus neonatorum it is met with in new-born children and in the dead foetus, is most marked on the palm of the hand and sole of the foot, and suggests syphilis. The blisters are easily ruptured, and one finds there only large, round, more or less detached bits of epidermis and under these a moist, dark red, or livid surface. It may be questioned whether variola should not also come under this head, as its eruption contains at first a clear watery fluid, though at a later period it becomes purulent, and is distinguished from all those vesicles of which we have spoken above by being umbilicated in the centre. The pus- tule of variola lies between the mucous and the horny layer SKIN AND SUBCUTANEOUS TISSUE. 19 of the skin and has a honey-combed character. Effusion of blood may take place into a small-pox vesicle as well as into any other, that of pemphigus, for instance. It is then called hcemorrliagic small-pox, but the eruption is, in this case, usu- ally rather papular, and but little characteristic. Not only the contents of the vesicles of variola, especially before they Tiave begun to be converted into pustules, but the underlying skin as well, are rendarkable for the presence of micrococci, which are easily demonstrated in fresh sections with the double knife, after treatment with glacial acetic acid or dilute caustic alkalies. There are but few tv\.j pustular eruptions (without vesic- ular initial stage), unless we include under this head acne and furuncles, which we shall treat of in connection with the glands and hair. Impetigo and those minute abscesses of emholio origin to which we alluded under Haemorrhage, con- stitute the class. These latter occur scattered over the whole body and appear as minute yellow spots, which may or may not be surrounded by zones of hsemorrhage ; they occur only in connection with the malignant form of ulcerative endocarditis in which, as will appear later more in detail, the thrombi contain large nests of micrococci. If thin trans- verse sections be made of the skin, either fresh or rapidly hardened in absolute alcohol, and laid under the microscope, it is easy to demonstrate the presence of a vessel filled with micrococci in the centre of each hsemorrhage or abscess. Papular inflammations form the last subdivision of this group, and include lichen, prurigo, and the papular Syphilide, with inflammatory growth in the papillary layer. (5.) Erysipelas (dermatitis) and its congener phlegmon (cellulitis) are distinguished by their diffuseness from those inflammations which are met with in small circumscribed spots and which we have already dwelt upon. The blush which is so characteristic of erysipelas during life often disappears entirely after death, and the indications of its having existed resolve themselves into diffuse swelling of the skin and sub- cutaneous cellular tissue, and their infiltration with an opaque 20 DIAGNOSIS IN PATHOLOGICAL ANATOMY. fluid rich in cells. In the early stage we see in a section placed under the microscope numbers of young cells, particu- larly along the course of the vessels, which cells later un- dergo fatty degeneration. Micrococci have been found in thß lymph vessels, as well as in the contents of the vesicles which often spring up on erysipelatous skin. Since the subcutaneous cellular tissue always participates in the swelling and infiltration with young cells resulting from simple erysipelas, it can readily be seen that increase in the intensity of these conditions may result in purulent in- flammation of this tissue (cellulitis). In this case, while the cutis is red and infiltrated, the subcutaneous tissue is swollen and its meshes are filled with opaque, yellowish, puriform or purulent fluid, erysipelas pTilegmonosum. Such suppuration may, of course, occur independently of erysipelas, and is then often of traumatic origin. It tends to spread horizontally, the superficial fascia preventing its deeper progress. If of long standing, the skin may be separated from the fascia over a large territory and a great cavity be formed, hanging from the walls of which, in greater or lesser number, bits of suppurating cellular tissue may be found. This is especially liable to occur if the inflammation is of an infective character (malignant, ichorous, gangrenous cellur litis), and in consequence of it the skin may become necrotic from disordered nutrition. Malignant cellulitis is often the result of contusions which are attended with haemorrhage, and the contents of the cavity may thus acquire a dirty brownish color. The walls are often studded with fresh haemorrhages, and are of a dirty greenish slate color. 3. In that form of necrosis of the skin, which we have just mentioned (sphacelus), the tissue is transformed into a soft, greasy, pulpy, dirty greenish or brownish colored mass (humid or moist gangrene). This is sometimes of consider- able extent, usually taking the form of bed-sores, so called, and is seated on the sacrum, the trochanters, the spinous processes of the vertebree, the heels, etc. The gangrene which sometimes follows frost-bite, and occurs chiefl}^ in the SKIN ÄND SUBCUTANEOUS TISSUE. 21 feet, is of the moist variety, though after detachment of the epidermis it may be eventually converted into the dry form. Special mention should be made of noma (cancrum oris)., a form of gangrene of the skin of the cheeks, lips, and nose, which is endemic in certain places, and which is not primary in the skin but extends outwards from the oral mucous mem- brane. Microscopic examination of the opaque foul-smelling fluid, into which in all these cases the tissue is resolved, shows granular masses of detritus, quantities of fat in both fluid and crystalline form, needle-shaped crystals of leucine and tyrosine, the latter arranged in the form of sheaves, crys- tals of triple phosphate resembling a coflin-lid in shape, and numberless bacteria, of all sizes and shapes, in active motion. A rosy-red color is produced, according to Virchow, by the addition of sulphuric acid to this gangrenous fluid. Anothier form of gangrene, called dry gangrene, to distin- guish it from the humid variety, next claims consideration. This form is also called mummification, and transforms the skin and subcutaneous tissue into a hard, black, or brownish black, mass. Sometimes it also is the result of pressure, and then occupies the same situations which have been enume- rated above, but its usual seat is the ends of the lower extrem- ities, and its cause plugging of a large artery or some other disturbance of the circulation. Thus in senile gangrene a predisposing cause is calcification of the arterial walls and the resulting diminution in calibre. It is true that it is uncommon for these changes, and the arterial thrombosis to which they give rise, to result directly in gangrene ; the im- mediate cause is rather to be found in small peripheral wounds or injuries which become inflamed, and this inflam- mation then assumes a progressive gangrenous character. Secondary arterial thrombosis may supervene on this and ex- tend upwards toward the trunk, and may be recognized as secondary by the evidences of gradual progression in the structure of the thrombus itself. In all cases of so-called spontaneous gangrene, the vessels which, relate to the part should be carefully examined. 22 DIAGNOSIS IN PATHOLOGICAL ANATOMY. A form of gangrene has been described and characterized as ivhite gangrene, which is a result of great distention of the skin, over tumors, for example, and is also sometimes the result of burns, the skin being transformed into a white, friable mass. Hospital gangrene Qgangrmna nosocomialis'), a poisoned condition of wounds, differs from the above described forms of gangrene, which all have one factor in common, their de- pendence on disordered nutrition. Wounds affected with hospital gangrene present a gray, coated surface, from which the gray mass can be only partially removed owing to the fact that it is infiltrated into the tissue, — local diphtheritis. This gray mass consists chiefly of micrococci (minute spheri- cal bodies either aggregated in masses, or strung together like beads on a rosary, and characterized by uniformity in size and a peculiar lustre), and bacteria (staff- like bodies of various lengths, sometimes darting and wriggling about, sometimes strung together in chains or collected in masses, in which latter case they are distinguished from collections of micrococci by the presence of a transparent and gelati- nous intermediate substance in considerable amount). To bring out these bodies clearly it is advisable to add to the microscopical preparation a little dilute caustic potash, which dissolves most organic structures but does not affect these organisms. An appropriate opportunity will be taken fur- ther on for showing the distinction between micrococci and fat drops. 4. Ulcers of the skin may be divided into simple or super- ficial and cavernous, and the latter class may be again divided into sinuous, with undermined edges, and fistulous ulcers. In the latter case ulceration extends in only one direction, forming a canal of varying width. These are usually con- comitants of affections of the bones and joints, and are due to the burrowing of pus outwards ; but they also occur in connection with affections of the serous cavities in the same way, and in both cases are called perforating fistulce or sinuses. If the fistula discharge one of the natural secre- SKIN ÄND SUBCUTANEOUS TISSUE. 23 tions, it receives a special name, as lachrymal, salivary, or urinary fistula. Witii reference to the condition of the gran- ulations at its base an ulcer may be indolent, with feeble and pale granulations, or fungous, with luxuriant granu- lations (proud flesh). If the granulations develop rapidly into tough and firm connective tissue, an indurated ulcer is the result ; if, on the contrary, they tend to break down rap- idly, a suppurating, pliagedenic, or gangrenous ulcer is the result. Many of the affections of the skin which we have already mentioned may give rise to ulcei'ation, as indeed we specified in some instances ; when we come to the discussion of new growths in the skin, we shall find that some of them may also give rise to ulceration, but of a progressive character. A few forms still remain for discussion here, the most com- mon of which is the well-known chronic ulcer of the leg. This is a typical indolent ulcer, with thick, indurated edges ; its base and circumference are indurated and in a state of chronic inflammation, and it shows but little ten- dency to cicatrization. In the neighborhood of such ulcers, scars, resulting from antecedent ones, are often met with, and usually present a brownish pigmentation. The ulcers may be of lai'ge extent in either direction, and may, indeed, involve the greater part of the leg. They are prevented from penetrating inwards by the tibia, which is often affected with superficial ossifying periostitis, but it may also become more deeply involved in the process, and thus superficial necrosis, or even osteomyelitis, be produced. Of the remaining kinds of ulcers we shall only mention the varicose, which occur over dilated veins ; the gouty, which are the result of the rupture of gouty deposits outwards ; and the scorhutic, which are characterized by hfemorrhage. 5. Ulcers result in cicatrices, which sometimes are char- acteristic of the special process which has given rise to them. For example, radiating, elevated, broad scars, generally in- dicate an extensive burn or cauterization ; kidney-shaped, glossy, irregularly depressed and pigmented scars, remain 24 DIAGNOSIS IN PATHOLOGICAL ANATOMY. after syphilis ; small, longitudinal, transversely striated scars of a silvery whiteness, occupying the deeper layers of the skin, and most abundant on the belly and thighs — the cica- trices following pregnancy — depend on rupture of bundles of the cutaneous connective tissue from great distention, and hence are not cicatrices at all, strictly speaking. The dis- tention is usually dependent on pregnancy, but may be due to ascites, anasarca, or great accumulation of fat. 6. Apart from parasitic diseases, to which we shall come later, there are but few changes in the epithelial appen- dages of the skin, the hair and the nails, or in the glands, which need detain us here. a. Premature baldness may be dependent either on indi- vidual peculiarity or disease (typhoid fever, syphilis, etc.). Alopecia areata or vitiligo, is indicated by loss of the hair in round patches, and consists, strictly speaking, in a breaking off of the hair at the surface of the skin in consequence of a peculiar disturbance of nutrition. A furuncle or boil consists in acute purulent inflammation about, and necrosis of, the hair follicles, especially those of the downy hairs. If sev- eral furuncles be closely aggregated — more common on the back than elsewhere — they form what is called a carbuncle, the skin over which, after the necrotic hair follicles have come away, is riddled and honey-combed. b. The nails may be variously distorted, in consequence of inflammation of the bed, especially of that portion of the matrix which forms the fold (paronychia), or in consequence of increased cellular formation in