Impetigo

IMPETIGO (from Latin impetus—attack, seizure), a contagious pustular eruption, superficial, which does not cause ulceration and does not leave a scar; it is caused by an externally introduced infection by pus-forming microorganisms—staphylococci and streptococci; the most characteristic morphological feature is the presence of loose, yellowish, brittle crusts. By true impetigo, one understands a staphylo- or streptodermitis arising on previously healthy skin and caused by the introduction and multiplication of pyogenic cocci, which penetrate either through accidental superficial cracks or abrasions, or through the orifices of sebaceous-hair follicles or sweat glands. Complication of a pre-existing dermatosis by pyogenic infection, to which vesicular or bullous dermatoses of any etiology are especially prone, is conventionally called impetiginization, and a dermatosis complicated by this infection is called impetiginized. Of course, the discs of impetiginized eczema or the pustules of impetiginized scabies can give rise to the subsequent development of true impetigo (Impetigo secundaria, s. deuteropathica). Guided only by the external appearance of the lesion, Roman and medieval physicians widely applied the term impetigo to all skin lesions covered on the surface by purulent crusts. The founders of modern dermatology, Willan and Bateman, refined the term impetigo, calling it superficial pustules that quickly dry into yellowish loose crusts. Wishing to emphasize the honey-yellow color of the crusts, Alibert gave impetigo the exotic name militagra flavescens. By the middle of the 19th century, many dermatological schools, observing complex dermatological forms in eczema patients, where discs of impetiginized eczema generated pure impetigo, and the latter, under the influence of scratching and the increased reactive capacity of the patients' skin, gradually "transformed" into eczema, created the term "pustular or impetiginous" eczema in order to resolve the difficulty. A major stage in the study of impetigo was the contagiousness of impetigo clinically established by Tilbury Fox, which is why he created the term impetigo contagiosa. The Vienna school, acknowledging the fact of contagiousness, created the term "parasitic eczema." The successes of bacteriology, especially the discovery of pus-forming microorganisms, the development by Sabouraud, Bockhardt, and others of methods for the correct cultivation of pyococci, etc., laid the foundation for a correct understanding of impetigo as a specific type of superficial pyoderma. Comparison of the clinical picture with bacteriological data established, at least for Europe, the existence of the following main types of impetigo. I. Impetigo streptogenes (Fox's impetigo)—streptococcal epidermitis (see separate table, figure 2); it is characterized by flattened, covered with a horny layer, slightly elevated phlyctenae, ranging from the size of a pinhead to a ten-kopeck coin, which are prone to peripheral growth; these phlyctenae are either scattered or clustered in groups, with a transparent or slightly cloudy, sometimes bloody content, surrounded by a thin hyperemic border. Arising quickly without subjective sensations, they rapidly dry into a thin yellowish crust, which falls off after 5–7 days and leaves a pale erythematous spot, outlined by a thin border of the horny layer detached by the former exudate. Children, adolescents, and young women are especially prone to the disease. The predominant localization is the face, less often the shins, feet, or hands. The infection arises at the site of accidental cracks, abrasions, scratches, insect bites, etc., and is easily transferred to healthy areas, especially by fingernails or a towel. Histologically, they represent a flat blister filled with serous fluid and polymorphonuclear leukocytes, raising the horny layer above the Malpighian layer, which is infiltrated with leukocytes and edematous. In the papillary layer, there are dilated vessels, an edematous connective tissue stroma, and an infiltrate of wandering cells. — Clinical varieties. 1. Impetigo bullosa—large, hemispherical, tense or flaccid blisters, scattered in small numbers, usually on the hands, feet, and shins, especially in the summer, sometimes observed in epidemics in barracks, children's homes, etc. An example of such impetigo is panaritium superficiale from a hangnail, manicure, needle prick, etc., on the fingers near the nail. — 2. Impetigo circinata—impetigo with large phlyctenae, quickly drying in the center and spreading at the periphery, which creates figures of rings, crescents, garlands, etc. Depending on the external appearance, these forms are given the names impetigo gyrata, figurata, etc. — 3. A practically important variety—the bullous or pemphigoid form of impetigo, the so-called pemphigus contagiosus neonatorum, which affects newborns sporadically or epidemically (for example, in maternity hospitals). Amidst complete health, several elements of bullous impetigo arise, either on unchanged or on hyperemic skin. In some places, they heal, forming a falling-off crust-scale; in some places, they give a type of confluent or circinate impetigo; in some places, losing their covering, they give erosions, which in severe cases spread and heal with difficulty; localization—the trunk and limbs, with the exception of the palms and soles, but with the possibility of impetiginous panaritiums, rarely—the face. Development of impetigo on the mucous membranes of the mouth, nose, and eyes is possible. The usual duration is 4–6 weeks. Recovery usually occurs; less often, in weak infants, the development of ecthyma, skin abscesses, skin gangrene, and symptoms of sepsis occurs. Some epidemics have a mortality rate of up to 30–50%. In severe cases, complication by dermatitis of the type described by Ritter is possible. Sources of infection: sick children, hospital staff having manifestations of primary or secondary impetigo, contaminated linen, baths, etc. — 4. Impetigo anguli oris, angulus infectiosus, perleche, or bridou—forms from an ephemeral phlyctena in one or both corners of the mouth and represents a small, linear, superficial, and therefore slightly painful reddish crack, covered with a linear brownish crust, bordered by matte-white strips of macerated epidermis. It is more common in children, sometimes in the form of family or school epidemics (kissing, shared utensils, etc.). Without treatment, it can last for months, which is further facilitated by carious teeth, digestive disorders that change the composition of saliva, etc. — 5. Impetigo of the mucous membranes—small phlyctenae, sometimes resembling aphthae, sometimes eroded, arising on the mucous membrane of the mouth, nose, conjunctiva of the eyelids, and the eyeball, sometimes even on the cornea in children with impetigo on the skin. — 6. Impetigo vegetans—starting as ordinary impetigo, it gives vegetative discs, which become covered with purulent crusts and are surrounded at the periphery by an undermined horny layer of exudate. — 7. Dermatitis bullosa streptogenes chronica—a rare form characterized simultaneously by bullous impetigo and annularly arranged vesicles of the Duhring's dermatitis type, which quickly become covered with impetiginous crusts. Outbreaks of focal erythroderma are possible. It is observed in children after scarlet fever or purulent panaritiums, is accompanied by fever, and lasts up to 6–8 months. — With any impetigo, the development of other forms and complications of pyoderma is possible—lymphangitis, lymphadenitis, furuncles, abscesses, and especially pyogenic nephrosis. Characteristic for the recognition of streptococcal impetigo are: 1) initial small flat phlyctenae, 2) thin crusts surrounded by a rim of undermined horny layer of exudate, 3) absence of redness and vesicles, 4) involvement of exposed areas, 5) benign course, 6) absence of itching, 7) presence of pyococci in the contents of the initial phlyctenae. It is practically important to examine the crusts of any atypical impetiginous disc located near natural orifices for Klebs-Löffler bacilli. — Prevention. A patient with impetigo should not kiss, must have separate utensils and linen, cut fingernails short, and wipe fingers with alcohol (those around them need to wipe exposed parts with camphor alcohol and protect every abrasion with collodion or a plaster). Treatment. There are two treatment systems: according to the first, all crusts are soaked with fat, the covering of the blisters is torn off, the erosions are wiped with a 1/2-percent solution of zinc sulfate and copper sulfate, dried, and smeared with zinc ointment with the addition of 1/2% salicylic acid, which is repeated several times a day. According to the second, the affected areas are not washed, the healthy skin is wiped 1–2 times a day with camphor alcohol, dried, and powdered; the affected areas are smeared 2 times a day with a thin layer of boric-tar ointment (4:3:30) and powdered with boric (1:10) talc. On the 3rd day, the ointment is wiped off with vegetable oil (but not the crusts) and the smearing is resumed. Recovery with both systems occurs in the same period of time. Large blisters are punctured; in the circinate form, it is necessary to cut off the horny layer raised at the periphery to the edges. In case of a febrile state, deep pyoderma, and nephrosis—quinine internally and urotropin intravenously (up to 5–10 g per day). II. Impetigo staphylogenes, s. pilaris, s. impetigo Bockhardt'a—staphylogenic ostio- or porofolliculitis, a group of isolated spherical pustules ranging from the size of a pinhead to a lentil, filled with thick yellowish-green pus, pierced in the center by a hair, and surrounded by a hyperemic border.

Slowly drying, the pustule turns into a cone-shaped brown crust, upon the falling off of which a pinkish spot remains, surrounded by a rim of detached whitish horny layer. The evolution of each pustule lasts from 7 to 8 days. Histologically: purulent melting of the inner layers of the epithelium of the hair follicle, forming an elliptical cavity, with phenomena of inflammation in the perifollicular tissue. Only the follicles of adult hairs are affected in persons of any sex and age. Rubbing of the skin, maceration of it with compresses, plaster, seborrhea, lack of cleanliness, entry into the follicles of irritating solutions, as is observed in workers of sugar refineries, ice-making, cement and other factories, work in a dusty room, etc., favor the development of Impetigo. Poor nutrition, hyperglycemia, increased sweating, congenital width and depth of hair follicles, etc., also favor the development of Impetigo. Complications in the form of deep pyoderma, especially furunculosis, are not uncommon. Diagnosis does not present difficulties. Prophylaxis: shaving of hair, cleaning of healthy skin with warm water and alcohol with subsequent drying, protection of it from dust and maceration. Treatment: avoid washing the affected area of the skin; cutting (not shaving!) the hair on the affected area and its periphery; cleaning healthy areas with alcohol with subsequent drying; daily opening of all pustules and removal of pus with a cotton swab. III. Impetigo vulgaris - streptostaphylogenic epidermitis, the most frequent form of pyoderma, especially of the face, in children. The initial phlyctena of streptococcal Impetigo, due to rapid infection with staphylococci, turns into an ephemeral yellow-honey pustule, giving thick, crumbly crusts, as if composed of separate lumps, of an ocher-honey color. Eruptions are usually multiple, rapidly spreading. A common complication is swelling of the regional glands and the possibility of furunculosis. Clinical varieties: 1. Impetigo granulata, s. pedicularis of women and girls with long hair, depending on the presence of head lice, scratching, and the introduction of pyogenic infection. Initial eruptions of banal Impetigo under the braid on the back of the head rapidly spread to the neck, back, face, and ears. Localization, the presence of nits and lice, and brown bead-like impetiginous crusts on the hair establish the diagnosis. 2. Impetigo scabiosa (pyogenic complication of scabies) - isolated large crusts a) on the extensor side of the elbow; b) on the head and shaft of the penis in males; c) on the areola of the nipple in women; d) on the buttocks and inner side of the thighs. 3. Impetigo pediculosa (pyogenic complication of pediculosis) - the same eruptions on the sacrum and in the region of the shoulder blades (along with scratch marks). 4. Impetigo scrofulosa - frequent outbreaks of Impetigo in children near the nose, ears, and along the edge of the eyelids, depending on the presence of chronic catarrhs in these areas. Diagnosis is not difficult. Prophylaxis: cleanliness of the body and hair, treatment of scabies, phthiriasis, catarrhs of the nose, ears, conjunctiva, etc. Treatment is the same as for streptococcal Impetigo. For Impetigo from pediculosis - abundant lubrication of the hair at night with petroleum jelly, washing with tar soap, and lubrication of the scalp with sulfur-tar ointment (4:3:30) for 3-4 days. Impetigo syphilitica - an old name for exudative-purulent papular syphilid - papules of various sizes with polycyclic contours, covered on the surface with a group of small ephemeral pustules, which, merging and drying out, give granular, brittle, porous crusts, usually of a dull dark brown color due to the admixture of blood; sometimes they take a confluent and circinate form: healing in the center without a scar, but with intense pigmentation, they spread along the periphery, giving disks up to 10-15 cm in diameter. It represents one of the forms of the so-called malignant (erosive-ulcerative) syphilis. It usually exists alongside other forms of pustular syphilid, from which it differs by greater polymorphism, a dense and brownish-red base, relative compactness and dark color of the crusts, localization on both open and closed parts of the body, the presence of other signs of syphilis, etc. Impetigo herpetiformis (herpes pyaemicus), a very rare (up to 1929 about 60 cases) dermatosis studied by the Vienna school, is clinically characterized by a sudden febrile state and the appearance in the femoral triangle of edematous-erythematous disks, closely studded with small pustules, which within a few days dry into an impetiginous crust covering the edematous-erythematous and eroded skin, while an erythematous-edematous ring studded with pustules spreads along the periphery. Individual disks merge, and new foci arise in the armpits, in the breast folds, and around the navel; subsequently, other areas of the skin and even the oral mucosa are affected. Subjective sensations are absent. A typhoid state and cachexia complement the symptomatology. Mortality is at least 70 percent, within a period of 2 weeks to 6 months. Even after recovery, a tendency to relapse persists. Variations: 1) development of vegetation under the crusts; 2) simultaneous existence of eruptions of the type of urticaria, exudative erythema, pemphigus, Duhring's dermatitis, etc.; 3) alternation, during relapses, of eruptions of the type of either Duhring's dermatitis or Impetigo herpetiformis; 4) 'transition' of small-pustular rash into pemphiginous; 5) upon outcome in recovery, 'transition' of pustular disks into psoriasiform and psoriatic (Neumann, Leszczynski); 6) simultaneous existence of symptoms of tetany, either overt or latent (F. Walter, Lutz). Histologically: banal phenomena of superficial dermatitis with perivascular infiltrate of polymorphonuclear leukocytes, also penetrating the epidermis. Most often Impetigo herpetiformis is a dermatosis of pregnancy or the postpartum period. Several cases have been described in women outside of pregnancy, in virgins, men, and boys. At autopsy, in some cases, endometritis, purulent peritonitis, and phenomena of sepsis were found. The content of fresh pustules is sometimes sterile, sometimes contains staphylococci-streptococci. Brill established a disturbance of calcium metabolism; F. Walter and others established pluriglandular insufficiency, especially of the pituitary and parathyroid glands, which is why the hypothesis of endocrine damage is plausible. Milian points to the possibility of a filterable virus (smallpox-like), causing pustular keratitis in a rabbit with reinoculations. Diagnosis with a typical picture and in pregnant women is not difficult. Characteristic are the localization, the small-pustular nature of the rash, the ring-shaped configuration, and the typhoid state. With a different localization, outside of pregnancy, and a satisfactory general condition, the diagnosis is always doubtful (Duhring's dermatitis, staphylostreptodermia). Treatment: locally - symptomatic; generally: during pregnancy - artificial induction of labor, injections of blood serum of a healthy pregnant woman (F. Walter); Goldschmidt and Kostromin in their case, where streptococcal infection was possible, saw success from the injection of autovaccine (Streptococ. pyog. brevis).