Ichthyosis

ICHTHYOSIS, ichthyosis (from Greek ichthys - fish), fish scale, crocodile skin, xerosis cutis, xeroderma, keratoma diffusum, a rare, appearing in early childhood, chronically proceeding hereditary generalized anomaly of keratinization, which is characterized by significant dryness of the skin or, conversely, increased sweating, proliferation and elongation of the papillae and the formation of abundant scaly layers, starting from the accumulation of the finest grayish-ash-colored bran-like plates up to massive conical or flat, tightly adherent horny outgrowths of a greenish or brownish-black color. Two forms of ichthyosis are distinguished: i. vulgaris and i. congenita. - A. I. vulgaris (Ordinary ichthyosis). Etiology and pathogenesis. Ichthyosis is a hereditary disease. The property of ichthyosis to frequently pass by heredity and affect several members of the same family has long been noted by both clinicians and biologists and has served as the subject of many investigations and observations. As for the nature of heredity of ichthyosis, it is known regarding i. congenita that it is transmitted in a recessive manner (inter alia, consanguinity of the parents is sometimes noted in this regard), while in relation to i. vulgaris this question cannot be considered finally resolved. Siemens defines it partly as a recessive affliction, partly dominant. Leven presents a pedigree tree of an ichthyotic family covering 4 generations, and on the basis of its detailed analysis comes to the conclusion that i. vulgaris is most likely inherited as a dominant trait. Many cases of hereditary transmission of i. vulgaris have been registered and described in modern times as well. Thus, Levin demonstrated in 1924 at a meeting of the New York Academy of Medicine a 38-year-old ichthyotic, whose mother, maternal grandmother, 3 sisters, and 6 brothers suffered from the same disease. Ramorino at the XX Congress of Italian Dermatologists (1923) reported a case of ichthyosis recurring over the course of 5 generations. Ravitch in the Chicago Dermatological Society in 1925 demonstrated an ichthyotic whose father, brother, and child were ill. Breda observed ichthyosis in a mother and 8 children. An interesting old observation by Tilesius: in 1802 he studied and described the famous English Lambert family, which suffered from i. hystrix, traveled around Europe, and exhibited themselves for the purpose of earnings under the name of "porcupine men." The disease was observed in them in four generations and affected only men. - The mechanism of these disorders has not yet been elucidated. Some authors are inclined to regard this process as an anomaly of keratinization (Gassmann); others consider the primary cause of ichthyosis to be a disease of the epithelial or connective tissue part of the skin; thirdly, based on certain pathoanatomical data, as well as on the absence in the area of affected skin zones of a vascular reaction, pilomotor reflex, sebum and sweat secretion, they regard this disease as...

vegetative neurosis (Leloir, Nikolsky). The endemic spread of ichthyosis in certain places (Paraguay, Indian Archipelago) should be explained not by special climatic influences, but by the hereditary transmission of the disease among a closely living population (inbreeding, "endogamy"). Thus, Lesser (Edmund Lesser) explained the endemic dominance of ichthyosis in certain localities cut off from communication with other countries, for example, in the Moluccas. Pathological anatomy. The main changes concern the epidermis and especially its cornified layer. The latter, depending on the clinical form of ichthyosis, may be in a state of greater or lesser hyperkeratosis. Sometimes (in ichthyosis hystrix) hyperkeratosis reaches a colossal degree, forming massive, tall columns. Occasionally, areas of parakeratosis are encountered here and there. The remaining layers of the epidermis can be either correspondingly thickened or, conversely, thinned (atrophy stage). Abundant mitoses are often found in the basal layer. The papillae are either almost unchanged or, especially in pronounced forms of ichthyosis, appear also hypertrophied and elongated in the form of small spines. In the papillary and subpapillary layers, an insignificant, predominantly perivascular infiltration is observed, consisting of lymphocytes, among which more or less abundant accumulations of mast and pigment cells are encountered in places. Collagen fibers are shrunken here and there or hyalinized. Elastic tissue, especially in the papillae, is atrophied. Sebaceous and sweat glands are altered and often are in a stage of atrophy. Hair follicles, as well as sweat glands, often appear keratinized. The arrectores pili muscles are altered and atrophied. In addition to lesions found on the skin, some authors found peripheral neuritis and radiculitis (Leloir), as well as atrophic changes in ganglion cells in the spinal cord and sympathetic ganglia (Sirsky). Clinical picture. The main clinical signs of the disease are scaly layers and dryness of the skin [see separate table (pp. 303-304), figures 3 and 4]. In typical cases of moderate intensity, the skin on the affected areas appears moderately reddened and covered with polygonal or elongated dry scales, more densely attached in the center and, as it were, lagging behind and raised at the edges, which somewhat resembles fish scales in appearance. The color of the scales is very diverse - from whitish, yellow-brown to green and even black shades. -- According to the intensity of the skin lesion, several forms of ichthyosis vulgaris are distinguished. 1. Xeroderma - the mildest form of the disease - is characterized by significant and uniform dryness of the skin, which, almost without changing its color, appears brittle, hard, and rough. It is covered with the finest branny scales, appearing in places as if dusted, in places forming fine wrinkling resembling crumpled tissue paper. On the extensor surface of the extremities and on the buttocks, where a special state of follicular keratinization called lichen pilaris or keratosis pilaris often develops in this form of ichthyosis, skin dryness reaches a particularly significant degree. Cases are frequent when lichen pilaris, expressed to varying degrees, constitutes the only, completely non-disturbing sign of ichthyosis for the patient. 2. Ichthyosis simplex. In this form, peeling is more clearly expressed. Small, shiny, lentil-sized or larger, whitish scales that lie freely are located on dry skin. At the same time, the striation or striated pattern of the skin clearly stands out. The 1st and 2nd forms can exist simultaneously on different areas of the body. - 3. Ichthyosis n i t i d a (shiny, syn. ichthyosis nacrée - pearly ichthyosis of French authors). In this form, the keratinization process becomes more intense, polygonal, thickened, and large scales the size of a 10- or 20-kopeck coin are formed. The color of the scales is either ash-gray or yellowish-brown, sometimes greenish; they are free at the edges and firmly attached in the center. The entire surface of the skin appears mosaic, shiny, and as if reflective. This form can also be observed simultaneously with the first two. - 4. Ichthyosis serpentina, s. sauriasis. In this form, we are dealing with more powerful horny layers, which represent thick, very dense-to-touch shields or cubes, clearly demarcated from each other, arranged like tiles or a carapace and indeed very much resembling the skin of a snake or crocodile. These layers usually have a brown or greenish-black color, due to which the affected areas seem dirty, unwashed. However, in reality, the dirty color of the shields depends on a special pigment that can be extracted with fat-dissolving substances. - 5. Ichthyosis hystrix (hystrix - porcupine). In this form, the horny layers reach particularly large sizes, forming layered, blunt-conical, stalactite-like, protruding horny masses. The color of these horny formations is either gray or light brown or dark brown and even completely black (a special variety - ichthyosis nigricans). Such a degree of lesion is more often observed in limited places, although occasionally it can have a significant spread, capturing extensive areas, and then the patient's skin really very much resembles the carapace of a porcupine. Sometimes ichthyosis hystrix can be combined with other, milder degrees of ichthyosis. In addition to the listed, sharply demarcated forms of the disease, all sorts of transitions can be observed between them in the same patient or at different periods of the disease. Course of the disease. The first signs of the disease usually appear in the second or even third year of life. From this time on, a certain dryness and roughness of the skin is noticed in children. Then the disease gradually intensifies and by the period of puberty reaches full development, taking the form characteristic of the given case, and in this state remains as a rule until the end of life. Eruptions in ichthyosis are rarely limited. Usually they have a diffuse, even universal character and, being located symmetrically, predominantly capture the extensor surfaces of the extremities, especially in the region of the elbow and knee joints. On the extremities, the intensity of the eruption increases from top to bottom. In addition to the indicated localization, the lesions also spread to the skin of the trunk and head. However, on the face, ichthyosis usually proceeds easily, in the form of xerosis; on the scalp, it is expressed either by increased branny peeling or follicular rash (ichthyosis follicularis), very reminiscent of monilethrix, with which many identify it. Only the palms, soles, and the region of joint folds, intergluteal folds, and genitals as a rule remain spared. Usually, the skin of the palms and soles differs only in insignificant dryness and wrinkling, but in some atypical cases, ichthyosis can predominantly be located on these parts, as well as in the armpits, inguinal regions, etc. Mucous membranes are usually not affected in ichthyosis. Hair loss is not often observed. The vellus hair on the extensor surfaces can be thinner and sometimes thins out; in other cases, hypertrichosis is observed. The hair of the head, armpits, and pubic region in severe forms of ichthyosis becomes dry, twisted, dull, and heavily thinned, persisting only in separate areas. Nails are affected very rarely (usually in universal forms of ichthyosis), and then their plates thicken (onychogryphosis), becoming ridged, dull, and brittle. Sweat and sebum secretion is very much reduced or completely absent, as well as the vascular reaction of the skin and the pilomotor reflex (Nikolsky). With significant spread of the process (due to impaired skin function), small daily fluctuations in temperature and a feeling of shivering appear. Subjectively, patients feel dryness and tension in the entire skin, sometimes moderate itching. The appearance of cracks causes pain. With insufficient hygienic care, various complications are added in the form of pyoderma, artificial dermatitis, and especially eczemas, to which, according to many authors, ichthyosis patients are very prone. But in general, the skin of these patients usually tolerates any irritations well, only rarely showing special sensitivity (ichthyosis irritabile; Besnier). The general condition of patients even with severe degrees of ichthyosis as a rule is not disturbed. Internal organs are not affected. It is also undeniable that living conditions (individual environment) have a significant impact on the course and tolerance of the disease. Thus, good nutrition and constant hygienic care, staying in an appropriate (warm) climate can significantly improve the state of the skin; on the contrary, dirt, crowding, unbearable labor contribute to complications. Diagnosis. Recognition of ichthyosis, especially in typical cases, presents no difficulties. When localized on the palms and soles, congenital keratoma should be kept in mind, but in this disease, the rest of the skin cover usually presents no deviations from the norm. Mild forms of ichthyosis can give rise to confusion with branny peeling in weakened subjects or with dry and scaly skin of the elderly.

However, the presence of cachexia in the first case and advanced age in the second allow for a correct diagnosis. Prognosis. The prognosis, especially in mild degrees of ichthyosis, is favorable. In more severe forms, it worsens somewhat, since a series of subjective disorders and painful fissures render patients incapable of practicing a trade and generally of doing heavy physical labor. In summer, or in a warm climate, the patients' condition improves; this is also facilitated by constant hygienic skin care (baths, fat greasings, etc.). Regarding curability, the prognosis is unfavorable—the disease is incurable, except for the rarest of cases (Hebra, Hardy) of recovery when congenital ichthyosis passed after acute infectious diseases—measles, smallpox, etc. Treatment is only symptomatic. Cod-liver oil, arsenic, iron, organotherapy (thyreocrine, hormine, etc.) prescribed in individual cases generally do not yield any noticeable effect, nor does X-ray irradiation or mountain sun. Only some authors have seen success when prescribing the listed remedies at a childhood age. Undoubtedly, a much greater effect is produced by the external application of various remedies. Thus, in mild and even moderate forms of ichthyosis, it is possible to maintain the skin in a satisfactory state by means of washings, or even better, warm baths and soapings. One should use either basic superfatted soaps or those with the addition of sulfur, tar, resorcinol, etc. Grease applications [Vaselin+Lanolin aa, Ung. simplex, Ung. boricum 3%, Sp. salicylic. (1-5%), Ung. sulfurat. (1-10%), etc.], general massage, and faradization are also very useful. When prescribing baths, regarding their temperature, frequency, and duration, one should be guided by the patients' well-being, since the skin of some of them tolerates maceration very poorly. Larger horny layers, after appropriate softening with fatty ointments, are carefully removed with a scalpel (so as not to introduce a secondary infection). Eczema complicating ichthyosis is usually treated according to general rules; at the same time, it should be kept in mind that patients with ichthyosis tolerate tar preparations well and they can be prescribed very early. B. Congenital ichthyosis (i. congenita, s. fetalis, s. intrauterina). This is a very rare disease. It appears in a developed state by the time of the child's birth and only as an exception at a later time. The disease is characterized by general redness of the skin, very severe degrees of keratinization, increased sweating, and a progressive course. Since both clinically and biologically, as mentioned above, a definite difference exists between i. vulgaris and i. congenita, the question of separating these forms from each other should be considered resolved. - Clinic and course. Two forms of congenital ichthyosis are described: 1) ichthyosis congenita in the proper sense and 2) erythrodermia congenitalis ichthyosiformis (Brocq). 1. In ichthyosis congenita, besides massive horny layers, other developmental defects are simultaneously observed (e.g., hare-lip, etc.). According to the degree of clinical phenomena, severe and mild forms of congenital ichthyosis are distinguished. In the former, separated from each other, polygonal, gray-yellow-colored, horny plates form

a tortoise-like carapace. At the same time, there is disfigurement or complete absence of the nose, ectropion of the eyelids and lips (the so-called "fish mouth"), complete defect or underdevelopment of the auricles, parts of the hands and feet, etc. These human-like creatures are usually born dead prematurely or die in the first days of their life (i. congenita gravis). In the milder form (in approximately half of all cases), the keratinization anomaly and other developmental defects are expressed much more weakly. Children are born on time and can remain viable (i. congenita larvata). In some cases, the disease appeared several days, weeks, and even months after birth. The future fate of such children is determined by the degree of clinical severity of the process (i. congenita tarda). - 2. Erythrodermia congenitalis ichthyosiformis (erythrodermie congenitale ichthyosiforme avec hyperepidermotrophie generalisee Brocq). This very rare variety of the milder form of congenital ichthyosis appears at the birth of the child or arises at later dates and is characterized by the following clinical signs: a) diffuse redness, most sharply expressed in the region of the neck, flexures, and extremities, b) general hyperkeratosis, especially strong on the neck and flexor surface of the joints, in places resembling i. hystrix, c) expressed phenomena of greasy seborrhea of the head, and finally d) a tendency to form blisters. The latter spread by autoinoculation, representing as it were an impetigo arising due to cracks in the epidermis (Darier). In this disease, the palms and soles are also significantly affected (ichthyosis palmaris et plantaris). The hair and nails not only do not fall out, but (according to Vidal and Brocq) can grow 2 or 3 times faster than normal. With age, all phenomena of the disease are significantly weakened. - Diagnosis does not present difficulties: Brocq's erythroderma must be distinguished from ordinary ichthyosis and congenital ichthyosis, which is not difficult, taking into account the clinical signs given above. - Prognosis in severe forms is hopeless. Treatment is similar to the treatment of i. vulgaris. In congenital Brocq's erythrodermia, it was sometimes possible to obtain a good effect from the prolonged use of thyroidin.