Reprinted from the Journal of Cutaneous and Genito-Urinary Diseases for February, 1890. , ICHTHYOSIS LINEARIS NEUROPATHICA. By FREDERICK PETERSON, M. D., Lecturer on Nervous and Mental Diseases at the New York Polyclinic. AT a meeting of the Christiania Medical Society, April 24, 1889, Dr. August Koren read a paper with the above title, which is pub- lished in the Norsk Magazin for Laegevidenskaben of September, 1889. He said ichthyosis, as is well known, is, as a rule, a diffuse disease, generally spreading from the extensor side of the extremities over the whole body, with the exception of the face, scalp, flexor surfaces of joints, palmar and plantar areas, and the genitalia, beginning usually in the first or second year of life and reaching its height about the age of puberty, when, in spite of all treatment, it remains stationary, except that toward the close of summer the skin may often become more soft and moist for a time, soon returning, however, to its previous condition. The disorder does not affect the general health of the patient. The forms described as serpentina, cornea, and hystrix are merely the various developmental stages of the disease. General diffuse ichthyosis is never, according to the authors, congenital, but appears at the earliest in the second month of life- But, in his own experience in the skin department of the Rigshospital, he had seen a case of normally developed ichthyosis serpentina that was con- genital, and a similar case had also previously been under treatment at the same hospital. Furthermore, contrary to the statements in books on cutaneous diseases, he had observed the disease to extend also to the face, hairy scalp, plan- tar and palmar and flexor-joint surfaces. In one case it caused ectropion in both eyes. Dr. Bidenkap, who had seen so many cases in Norway, be- lieved that it spread to the face and head in the plurality of cases in that country. Ichthyosis congenita is a very infrequent disease, developing during intra-uterine life, and the child is, as a rule, still-born, or dies shortly after birth. Besides this diffuse form, there are rare cases of partial local ichthyo- sis, such as ichthyosis pahnaris and plantaris, differing singularly from the former, which rather avoids these particular surfaces. There are other local varieties, which, when highly developed like ichthyosis cornea or hystrix, have no small resemblance to ncevi materni, because of their pa- pillomatous and brownish appearance. But the horny character will often serve to distinguish ichthyosis from these. An observation of Dr. R. Hilbert (Virchow's Archiv, vol. xcix, page 569) in a twenty-four-year-old girl in Bremerhaven is of interest here. There was hypertrichosis of the whole left arm, with a small ichthyosis serpen- tina in the scapular region about an inch in diameter. (Her mother had seen an ape during pregnancy.) VOL. VIII.-6 58 Original Communications. Dr. Koren presented drawings of a noteworthy case of his own (see figure). It is an ichthyosis cornea developed in the form of brownish papillomatous stripes with normal skin lying between them. The stripes follow the median, ulnar, and radial nerves of the right arm. Along the median nerve the disease reaches only to the wrist joint, but along the radial it follows out over the hand to the first joints of the thumb and index finger on the dorsal surfaces, while it follows the ulnar on the volar surface to the tip of the little finger. There is, furthermore, a moderate development of the skin affection on the tips of the other four fingers. The disorder was accidentally discovered in a boy nine months old, to whom the author had been called because of an eclamptic seizure. He is the youngest of seven children, one of whom had died three days after birth. The five other children are living, and all delicate, anaemic, with pale skin and a tendency to catarrhs. The father suffers constantly from rheuma- tism, and has a mitral defect as the result of several severe attacks. The mother is chlorotic from cancer. There is no trace of heredity to be found in the family. The mother says the child was born with these stripes, that they were more marked during the first few days subsequent to its birth, and believes the improvement in the affection to be due to daily baths. The case impressed the author, as soon as he saw it, as one of naevus, but, as naevi undergo no change or improvement such as had taken place in this disease, he was led to think of ichthyosis; and closer observation Ichthyosis Linearis Neuropathica. 59 of the strongly developed epidermal layer, which felt like a grater on stroking it with the hand, assured him of the correctness of his diagnosis. At the same time there was a remarkable resemblance to a rare form of nae- vus, which, because of its asymmetrical appearance upon one side of the body, has been termed by von Barensprung ncevus unius lateris, and be- cause of its following branches of nerves has been called by Gerhardt papil- loma neuropathicum, but is more familiar under the name now in general use given by Simon, navus nervosus. Such naevi are uncommon, but an ichthyosis developing so exquisitely along nerve branches, as in this case, is still more rare. Less extensive eruptions of this nature are possibly not so infrequent. These forms of ichthyosis and naevus are so similar in pathologico- anatomical respects that it is not to be wondered at that there are transi- tional forms which might be considered either the one or the other, ac- cording to one's taste. Thus Neumann, in his atlas, places among the naevi a case which certainly should, according to the drawings, be rather included under ichthyosis. There is, moreover, a third cutaneous affection which ought to be men- tioned here, for the reason that it may at times make the diagnosis still more uncertain and doubtful, and that is verruca. Verruca may at times take an unusual course, following nerve trunks in linear stripes, so that there may be difficulty in differentiating navi nervosi from navi verru- cosi. But the excessive development of the epidermal layer, and the fact that there is diminution in intensity of the disease, will almost always serve to distinguish neuropathic ichthyosis. In the case described by Dr. Koren the drawings were made some ten months ago, and considerable im- provement has taken place, many of the plaques having disappeared. Naevi, on the other hand, never show such changes, but grow with the growth of the patient's body. It has been stated that the linear form of ichthyosis, like the navus unius lateris, develops asymmetrically-i. e., only on one side of the body. But there is a bilateral example to be found in literature. Dr. Thieberge (Annales de dermatologie et syphiligraphie, 1887, page 738) cites an obser- vation of Dr. Butruille: A six-year-old child presented the linear stripes of an ichthyosis cornea upon the backs of both thighs, following the sciatic nerves on the right side to the middle of the leg along the internal pop- liteal nerve, on the left some distance down the anterior tibiae. There was also a stripe six centimetres long on one of the median nerves. As in Dr. Koren's case, there was neither pain nor other disturbance of sensibility. As regards the causes of ichthyosis diffusa, they are still obscure. Le- loir, in his Recherches cliniques et anatomo-pathologiques sur les affections cutanees d'origine nerveuse, 1882, has found in this disease pathological changes in the cutaneous nerves. The condition in one case was that of 60 Original Communications. an atrophic degenerative neuritis. Leloir has found ichthyosis to follow various nervous affections, such as severe cases of sciatica, paraplegias, grave hysterical paralyses, Pott's disease, and lead intoxication. Schwimmer, in his work on Die neuropathischen Dermatonosen, 1883, pages 199 et seq., records numerous observations of various authors upon changes in the epidermis subsequent to neural lesions. The influence of the nerves in diffuse ichthyosis is mentioned in a num- ber of older works on cutaneous diseases. Hebra presents drawings of a striking case of this kind (see Hebra-Kaposi, Virchow's Handbuch der speciellen Pathologic und Therapie, 1876, vol. ii, page 41), and says that ichthyosis cornea and hystrix diffusa appear sometimes in the form of ir- regular stripes along the skin, following, as a rule, the peripheral spinal nerves. And Kaposi, in his Pathologie und Therapie der Hautkrank- heiten, 1880, page 517, speaks in a similar manner of ichthyosis hystrix. But whatever may be the underlying cause of the diffuse variety of the affection, there can be no doubt that the local linear forms are in reality due to a trophoneurosis. Lesser, in his Lehrbuch der Ilaut- und Ge- schlechtskrankheiten, 1885, pages 183 et seq., also speaks of a trophoneu- rosis as the probable setiological factor in the production of certain forms of ichthyosis. Duguet describes a striking case of ichthyosis serpentina, unilateral, following, analogously to herpes zoster, an intercostal nerve. For the trophoneurotic forms of ichthyosis, which have as yet received no name, Dr. Koren suggests the following designations : for the round, circumscribed variety, ichthyosis circumscripta neuropathica, and for that distinguished by linear stripes, ichthyosis linearis neuropathica. In a further examination of cutaneous literature I find nothing exactly like Dr. Koren's case, although there are references to neuropathic naevi and excrescences. Thus Thomson, in his Atlas of Declinations of Cuta- neous Eruptions, London, 1829, describes a case of naevus spilus following the nervus mentalis along the under lip, and another case in which a simi- lar growth followed the inner surface of the right arm along the ulnar nerve from the shoulder to the inner parts of the ring and little fingers. There is nothing in the atlases and works of Alibert, Cazenave, or Rob- ert Willis bearing upon the subject. Sir Erasmus Wilson describes neurotic excoriations in his Lectures on Dermatology, 1875. C. Gerhardt (Jahrb. fur Kinderheilk., 3. Heft, 1871) mentions a case of neuropathic papilloma. Lewin (Deutsche Zeits. fur prak. Med., 1877, No. 2) regards naevus as a trophic nervous disease. Campana (Giorn. it. delle mat ven. et della pelle, 1876) observed eleven cases of naevus following nerves, such as the first, second, and third Two Cases of Eczema Mercwriale. 61 branches of the trigeminus, the cutaneous branches of the third and fourth cervical, the intercostal nerves, the posterior branches of a spinal nerve (double), a lumbar nerve, the crural nerve, and a cutaneous branch of the plexus sacro-ischiadicus (bilateral). It is probable that such a case as Dr. Koren's, if presented to the New York Dermatological Society, would be considered a neuropathic papil- loma. Dr. Prince A. Morrow tells me that a few cases having mAny points of similarity with this have been exhibited before the society, and that descriptions of them may be found in some of the back numbers of the Journal of Cutaneous and Genito-urinary Diseases. I find little or no reference to disorders of this character in our later English works on skin diseases, almost the only one occurring in Jamieson's Diseases of the Skin (Pentland Medical Series, Edinburgh, 1888, page 379), where the author describes a case under the name of papilloma neuroticuni as " a peculiar disease allied to warts." Further observation and study will be necessary before it can be determined whether Dr. Koren has really added a new form of ichthyosis to those already known, or has merely described a case of papilloma neuropathicum presenting some unusual features.