From Big Medical Encyclopedia

FAVUS (Latin favus of cell, cellular cell; synonym: a scab) — the chronic fungus disease of skin caused by Trichophyton schoenleinii.

T. meets in all countries. In the USSR the favus as a mass disease is liquidated, isolated cases are celebrated.

Etiology. The disease is known from an extreme antiquity, but only in the middle of 19 century its activator was open. R. Remak in 1837 found it in sites of the affected skin, and I. Shenleyn in 1839 and D. Gruby in 1841 established its fungal nature. R. Remak called the activator Achorion schoenleinii, G. Gravitz in 1886 for the first time allocated a fungus in culture and described its morphology (see Achorion).

Epidemiology. Infection happens at contact (often long) to the patient F. or with things, to-rymi it used (a headdress, a hairbrush). Contageousness of a disease is small, however to emergence F. promote it is long the existing se.meyno-household centers. Almost in half of cases the disease is transmitted to children from patients F. mothers. In regions where the custom of traditional family carrying headdresses, T remained. it is often transferred in the male line. Children get sick preferential, among sick adults women prevail. Long time F. can remain unnoticed. The person can catch F. also from mice and rats. In these cases the disease flows more sharply, reminding infiltra-

a tivno-purulent trichophytosis (see), especially at localization of process on a pilar part of the head.

Pathological anatomy. Characteristic morfol. an element of the affected skin is the skutula, or the favose guard representing accumulation of elements of a fungus (a dispute in the center, a mycelium on the periphery), cells of epidermis and a fatty detritis. Skutula is surrounded with accumulations of leukocytes and the exudate containing the destroyed cells of an epithelium. The fungus in abundance contains in the beginning in a corneous layer of epidermis, then gets in malpigiyev a layer and even a derma, in the subsequent strikes a follicle of a hair and through an internal root vagina gets into a bulb and marrow of a hair. In connecting fabric of a derma the fungus causes the expressed inflammatory reaction with formation of the infiltrate consisting of lymphocytes, plasmocytes and fibroblasts. In a mode of formation skutul in mouths (necks) of follicles there is a thickening of a corneous layer and a hypertrophy of mal-pigiyevy. In a stage of an atrophy epidermis becomes thinner, in a basal layer the pigment disappears, grease and sweat glands collapse, collagenic and elastic fabric melts, the hem is formed. Sometimes the favose granuloma develops, the structure a cut can remind a tubercular hillock. In a regional limf, a node the thickening of the capsule and infiltration of vessels is often noted by lymphocytes. At damage of nails (see the Onychomycosis) the fungus usually is found in a nail plate and fabrics of a nail bed.

Pathogeny. To development F. microtraumas of a corneous layer of epidermis, duration of contact with the infected things (a headdress, etc.), substantially — decrease in immune responsiveness of an organism owing to intoxications, hron promote. diseases, defective food, hypovitaminosis. The fungus in an organism can extend in the hematogenous way.

Clinical picture. The incubation interval proceeds two weeks. Distinguish a favus of a pilar part of the head, smooth skin and nails. Sometimes also internals are surprised. Typiform F. a pilar part of the head is skutulyarny; allocate also squamous, impetiginous, infiltrative and suppurative, scarlet petsiyevidnuyu and granulematozny forms. At a skutulyarny form on site of implementation of a fungus there is a hyperemia, then the pustule with a peeling and growth of the center on the periphery is formed. Drying up, it takes a form of a yellowish crust with saucer-shaped impression and on -

Rice * 1. Head of the patient with a favus (skutulyarny form): the crusts on a pilar part of the head formed by the merged sku-tula.

a razhenny hair in the center — a skutula; its size is from several millimeters to 3 cm in the diameter. After removal of a skutula wet, slightly hyperemic deepening is bared. Skutula are inclined to merge (fig. 1), forming at etokhm stratifications large dirty-gray color of unpleasantly smelling crusts. Hair at F. do not break off; they are sometimes twisted, gradually become dim, pigmented or whitish («gray-haired»), lose elasticity, remind tow. In the subsequent, as a result of an atrophy of follicles, hair gradually become thinner and drop out. Process, slowly extending by a pilar part of the head (except the fringe region of growth of hair), leads to persistent baldness. Skin on places former skutul thin, smooth, brilliant.

Fig. 2. Body of the child of the patient with a favus: to a mnozha

stvenny skutula.

At a squamous form F. skutu-la are absent. In some cases they dot are also hardly noticeable among the macrolaminar, grayish-white densely sitting on skin scales (a psoriasiform version), or among a melkoplastinchaty peeling (a pitirioidny version). At removal of scales hyperemic atrophied skin is bared. Hair in the centers of a peeling dim, «dusty»; they, as a rule, drop out.

Impetiginous form F. occurs usually at children. Formation of the layered crusts of lurid color penetrated by the dim, affected with a fungus hair is characteristic of it. Crusts can cover entirely the centers or to be small, to border only atrophied sites of skin. Sometimes the disease is shown by the centers of trikho-fitoidny character in the beginning — on skin one or several groups of bubbles appear, gradually the centers increase in sizes, in the center the peeling is noted, the periphery of the center is made by the shrunk bubbles and small crusts, to-rye can accept the nature of impetigo (see), in nek-ry cases the inflammation abates and skutula are formed. At imnetiginozny defeats under crusts and scales it is possible to find mikroskutula (a mikrosku-tulyarny version).

Infiltrative - the suppurative form meets extremely seldom. She is characterized by the expressed purulent inflammatory reaction and reminds an infiltrative purulent trichophytosis (see).

The Alopetsiyevidny form meets seldom, the centers have an appearance small (to dia. to 1 cm), the atrophied, deprived hair of sites of skin. The peeling and skutul at the same time is not observed, hair on the periphery of the center lose gloss and elasticity.

At a granulematozny form favose granulomas — knotty educations in skin without signs of purulent fusion of fabrics appear.

Damages of smooth skin of a trunk and extremities proceed in the form of a skutulyarny form more often, and also eritematoskvamozny and vesicular, at to-rykh the single centers of defeat on skin usually remind a trichophytosis (see), seborrheal eczema (see), psoriasis (see). Sometimes process happens generalized (fig. 2), at the same time along with the centers of a peeling bordered with the hyperemic roller sites of a diffusion peeling with formation skutul in the form of the merging massive yellow crusts are noted. In some cases damage of skin of palms as is observed at hron. trichophytosis (giperkera-totichesky forms).

Damage of nails meets more often at is long existing F. pilar part of the head; the isolated onychomycosis, as a rule, of fingers of hands is occasionally noted. At F. nails the configuration of a nail plate a long time is kept, in it it is possible to find prosvechiv and yu shch and e yellowish color of a skutula. Afterwards the nail plate is thickened at the expense of a hyponychial hyperkeratosis, crumbles, gains rather dirty color.

Rare forms F are described., arising at hypovitaminoses, tubercular intoxication with endocrine disturbances; at the same time extensive sites of skin, mucous membranes, limf, nodes, a brain (encephalomeningitis), and also internals, by hl are involved in process. obr. went. - kish. a path where multiple ulcer defects are found. Nek-ry patients can have favids — is long the existing allergic rashes in the form of eritematoskvamoz-ny, papular and pustular elements, in to-rykh fungi are not found.

The diagnosis is established on the basis by a wedge, pictures. It shall be confirmed with data of microscopic examinations and allocation of culture of the activator. Differential diagnosis F. a pilar part of the head carry out with a trichophytosis (see), a microsporia (see), a pseudopelade (see), a lupus erythematosus (see), etc.; T. smooth skin differentiate with psoriasis (see), eczema (see), a streptoderma (see the Pyoderma); T. nails — with damages of skin at a tinea (see), a trichophytosis, candidiasis (see). At diagnosis of visceral defeats the specific nature of manifestations F helps. on skin and detection of the activator.

Treatment is carried out by griseofulvin in combination with local therapy. Griseofulvin is appointed at the rate of 15 mg/kg a day in three steps (during food with a teaspoon of vegetable oil). Within a month drug is accepted daily, after the first negative take of the analysis on a fungus — every other day, then 2 times a week to three negative takes of the analyses which are carried out at an interval of one week. At F. a pilar part of the head hair shave off, wash the head with warm water with soap every week (crusts, skutula, scales delete previously by means of bandages from 2 — 5% with salicylic vaseline). In the morning skin is greased by

2 — 5% with spirit solution of iodine, in the evening in it rub sulfur-tar ointment (3% of tar and 10% are gray). Treatment continues from 11/2 to 4 months. At contraindications to use of griseofulvin appoint 4% an epilinovy plaster, sometimes a roentgenotherapy. At damages of skin treatment same (at the single centers without damage of vellus hair — without griseofulvin). Treatment of an onychomycosis is carried out by griseofulvin with simultaneous removal of nail plates and the subsequent outside treatment of a nail bed fungicides (see). Much attention is paid to fortifying therapy, especially children, the elderly and weakened patients.

The forecast at defeat of a pilar part of the head, skin and nails usually favorable; in the absence of treatment F. can last for years. At damage of internals the lethal outcome is possible.


Prevention. Patients F. after the end of treatment stay on the registry in a dermatovenerologic clinic within a year. Along with the patient within a year examine the family members and persons contacting to the patient. In the centers F. repeated inspection of had is performed within 5 years once a year. For the purpose of active identification of patients in settlements, adverse on F., inhabitants are examined annually within 3 years after detection of the last patient. Control holding disinfection actions in the center and observance a dignity. - a gigabyte. governed.

See also Fungus diseases of skin.

Bibliogrk and shch to and N P. N. and Lisin V. V. Practical guidance on a medical mycology, page 39, L.,

1983; Leshchenko V. M. Laboratory diagnosis of fungus diseases, page 111, M., 1982: The multivolume guide to microbiology, clinic and epidemiology of infectious diseases, under the editorship of

H. N. Zhukova-Verezhnikov, t. 10, page 284, M., 1966; Gonant N. F. and. lake of Manual of clinical mycology, Philadelphia, 1971; EmmonsCh. W., Binford Ch. H. a. U t z J. P. Medical mycology, p. 115, Philadelphia, 1970; R e m a k R. Observationes anatomicae et microscopicae de systematis nervosi structura, Berolini, 1838.

V. M. Leshchenko.