Neurodermatitis

NEURODERMATITIS (neurodermitis), a term introduced by Brocq to denote dermatoses in which skin changes appear as a result of scratching caused by primarily occurring itching. The group of N. is not yet clearly defined. Two main types are distinguished: limited N. (p. circumscripta of Brocq, synonym lichen simplex chronicus of Vidal; see Vidal's lichen) and diffuse N. There are also so-called atypical forms of N.: hypertrophic N. ("giant lichenification"), hyperkeratotic (verrucous), follicular, diffuse facial lichenification, etc. Diffuse (disseminated) N. (p. diffusa) of Brocq, synonyms: prurit diffus avec lichenification, prurigo simplex chronica, prurigo vulgaris of Darier. The problem of etiology of diffuse N. is complex; it can apparently be caused by the most diverse factors; these primarily include functional lesions of the nervous system and metabolic disorders. Brack found in patients with diffuse N. a tendency to alimentary hemoclastic crises and to sympathicotonia with increased sensitivity of nerve endings in the skin. Darier classifies diffuse N. as autotoxic dermatoses; in some cases the toxic substance is one or another product of metabolism (glucose, bile acids, etc.); in other cases it is impossible to find the "culprit of toxic action". Ehrmann considered such a "culprit" to be disorders of the digestive apparatus. Jacquet speaks of the simultaneous existence of many causes causing itching and N., of the so-called "sommation prurigene" (sum of pruritic causes). At present, great attention in dermatology is paid to the doctrine of various skin types, which is why in relation to N. Brocq's idea of the so-called "predisposition" of the skin to lichenification is again put forward, the essence of which remains completely unclear. The influence of heredity in N. has not been studied, but one can quite definitely identify in cases of N. in children diseases of the nervous system and metabolic disorders in the family of the patient. The patho-anatomical picture of disseminated N. is not characteristic and for the most part completely corresponds to the changes found in chronic eczema: para- and hyperkeratosis, slight acanthosis, intra- and intercellular edema; edema of the papillae, dilation of vessels and perivascular round-cell infiltration in the true skin. The course of the disease and symptomatology. The clinical picture of diffuse N. is diverse; onset is always with attacks of severe itching; scratches at first sometimes cause urticaria or erythema, but soon the reaction of the skin to scratching manifests itself either in the eruption of numerous separate small lichenoid nodules or in the formation of poorly defined lichenified plaques. Therefore, one can speak of two main clinical types of diffuse N.: 1) on extensive areas the skin is thickened and transformed into a shiny uneven shagreen-like dark brown surface, its normal striation is exaggerated [lichenification (Brocq), or lichenization (Besnier)]; in places, both on these areas and outside them, there are separate small, flat, shiny, round or irregularly shaped nodular eruptions; 2) the latter predominate (partially merging), and only in separate places lichenified plaques are noted. The favorite localization of neurodermatitis: face, neck, joint flexures, genitalia. With regression of the eruptions, temporary pigmentation almost always remains. In some cases the eruption is linearly distributed (p. linearis, s. zonisformis).-By course, 3 forms of diffuse N. are distinguished: 1) onset in early childhood and persistence of the process thereafter; 2) onset at a later age, course also severe; 3) cases with a milder course, etiologically usually associated with a specific cause (diabetes, nephritis, jaundice, etc.) (Jadassohn). Diffuse neurodermatitis periodically improves and worsens, sometimes alternating with attacks of certain allergic conditions (bronchial asthma, hay fever, etc.). Often there is eczematization of individual foci (hyperemia, vesiculation, weeping), impetiginization is possible. Diffuse neurodermatitis is less common than limited. Diagnosis often presents difficulties. From disseminated chronic eczema, N. differs in the primary nature of itching with the subsequent development of lichenoid nodules, for the establishment of which sometimes long-term observation is required. From lichen ruber planus (see Lichen), diffuse N. differs in the absence of completely typical nodules of the first. In individual cases, the differential diagnosis of N. with Mycosis fungoides (see) may be difficult; sometimes only the appearance of skin infiltrates, and then tumors, helps in the correct diagnosis. From true prurigo, diffuse N. differs in the absence of typical, almost invisible to the eye, but only palpable isolated pruriginous nodules, the absence of significant enlargement of lymph glands (pruriginous buboes), the reverse localization (in flexures, and not on the extensor surfaces of the limbs, as in prurigo), etc.-Prognosis quoad vitam-good, quoad sanationem completam-for the most part unfavorable, since it is rarely possible to free the patient from recurrences.-- I Treatment of diffuse N.-a very difficult task for the physician; often for rational therapy a consultation of physicians of various specialties is necessary, since for successful treatment it is necessary to establish possible and very diverse causes of the disease. Therefore, for the general treatment of N., careful individualization is required: removal of worms, insulin for diabetes, intravenous infusions of sodium bromide (according to Lebedev) for increased excitability of the nervous system, ozenotherapy, etc.; physical therapeutic measures (ultraviolet rays, polysol, warm baths, etc.) do not always act equally successfully. There are indications of good effect in some cases of indirect radiotherapy (irradiation of spinal nodes). With general nutritional decline - arsenic, iron, cod liver oil. Local treatment consists in the application of ointments and pastes with pruritolytic and resorptive agents for infiltrates (mainly preparations of tar, sulfur and their derivatives). With eczematization and complications with pyogenic infection - appropriate treatment.