Fig. 1.
FIG. 1.
Vertical section of the skin—Diagrammatic. (After Heitsmann.)
Fig. 2.
FIG. 2.
c, corneous (horny) layer;g, granular layer;m, mucous layer (rete Malpighii).The stratum lucidum is the layer just above the granular layer.Nerve terminations—n, afferent nerve;b, terminal nerve bulbs;l, cell of Langerhans.
(After Ranvier.)
Fig. 3.
FIG. 3.
C, epidermis;D, corium;P, papillæ;S, sweat-gland duct.v, arterial and venous capillaries (superficial, or papillary plexus) of the papillæ.Deep plexus is partly shown at lower margin of the diagram;vs—an intermediateplexus, an outgrowth from the deep plexus, supplying sweat-glands, andgiving a loop to hair papilla.
(After Ranvier).
Fig. 4.
FIG. 4.
a, a vascular papilla;b, a nervous papilla;c, a blood-vessel;d, a nerve fibre;e, a tactile corpuscle.
(After Biesiadecki.)
Fig. 5.
FIG. 5.
A, shaft of the hair;B, root of the hair;C, cuticle of the hair;D, medullary substance of the hair.
E, external layer of the hair-follicle;F, middle layer of the hair-follicle;G, internal layer of the hair-follicle;H, papilla of the hair;I, external root-sheath;J, outer layer of the internal root-sheath;K, internal layer of the internal root-sheath.
(After Duhring.)
The symptoms of cutaneous disease may be objective, subjective or both; and in some diseases, also, there may be systemic disturbance.
What do you mean by objective symptoms?
Those symptoms visible to the eye or touch.
What do you understand by subjective symptoms?
Those which relate to sensation, such as itching, tingling, burning, pain, tenderness, heat, anæsthesia, and hyperæsthesia.
What do you mean by systemic symptoms?
Those general symptoms, slight or profound, which are sometimes associated, primarily or secondarily, with the cutaneous disease, as, for example, the systemic disturbance in leprosy, pemphigus, and purpura hemorrhagica.
Into what two classes of lesions are the objective symptoms commonly divided?
Primary (or elementary), and
Secondary (or consecutive).
What are primary lesions?
Those objective lesions with which cutaneous diseases begin. They may continue as such or may undergo modification, passing into the secondary or consecutive lesions.
Enumerate the primary lesions.
Macules, papules, tubercles, wheals, tumors, vesicles, blebs and pustules.
What are macules (maculæ)?
Variously-sized, shaped and tinted spots and discolorations, without elevation or depression; as, for example, freckles, spots of purpura, macules of cutaneous syphilis.
What are papules (papulæ)?
Small, circumscribed, solid elevations, rarely exceeding the size of a split-pea, and usually superficially seated; as, for example, the papules of eczema, of acne, and of cutaneous syphilis.
What are tubercles (tubercula)?
Circumscribed, solid elevations, commonly pea-sized and usually deep-seated; as, for example, the tubercles of syphilis, of leprosy, and of lupus.
What are wheals (pomphi)?
Variously-sized and shaped, whitish, pinkish or reddish elevations, of an evanescent character; as, for example, the lesions of urticaria, the lesions produced by the bite of a mosquito or by the sting of a nettle.
What are tumors (tumores)?
Soft or firm elevations, usually large and prominent, and having their seat in the corium and subcutaneous tissue; as, for example, sebaceous tumors, gummata, and the lesions of fibroma.
What are vesicles (vesiculæ)?
Pin-head to pea-sized, circumscribed epidermal elevations, containing serous fluid; as, for example, the so-called fever-blisters, the lesions of herpes zoster, and of vesicular eczema.
What are blebs (bullæ)?
Rounded or irregularly-shaped, pea to egg-sized epidermic elevations, with fluid contents; in short, they are essentially the same as vesicles and pustules except as to size; as, for example, the blebs of pemphigus, rhus poisoning, and syphilis.
What are pustules (pustulæ)?
Circumscribed epidermic elevations containing pus; as, for example, the pustules of acne, of impetigo, and of sycosis.
What are secondary lesions?
Those lesions resulting from accidental or natural change, modification or termination of the primary lesions.
Enumerate the secondary lesions.
Scales, crusts, excoriations, fissures, ulcers, scars and stains.
What are scales (squamæ)?
Dry, laminated, epidermal exfoliations; as, for example, the scales of psoriasis, ichthyosis, and eczema.
What are crusts (crustæ)?
Dried effete masses of exudation; as, for example, the crusts of impetigo, of eczema, and of the pustular and ulcerating syphilodermata.
What are excoriations (excoriationes)?
Superficial, usually epidermal, linear or punctate loss of tissue; as, for example, ordinary scratch-marks.
What are fissures (rhagades)?
Linear cracks or wounds, involving the epidermis, or epidermis and corium; as, for example, the cracks which often occur in eczema when seated about the joints, the cracks of chapped lips and hands.
What are ulcers (ulcera)?
Rounded or irregularly-shaped and sized loss of skin and subcutaneous tissue resulting from disease; as, for example, the ulcers of syphilis and of cancer.
What are scars (cicatrices)?
Connective-tissue new formations replacing loss of substance.
What are stains?
Discolorations left by cutaneous disease, which stains may be transitory or permanent.
What do you mean by a patch of eruption?
A single group or aggregation of lesions or an area of disease.
When is an eruption said to be limited or localized?
When it is confined to one part or region.
When is an eruption said to be general or generalized?
When it is scattered, uniformly or irregularly, over the entire surface.
When is an eruption universal?
When the whole integument is involved, without any intervening healthy skin.
When is an eruption said to be discrete?
When the lesions constituting the eruption are isolated, having more or less intervening normal skin.
When is an eruption confluent?
When the lesions constituting the eruption are so closely crowded that a solid sheet results.
When is an eruption uniform?
When the lesions constituting the eruption are all of one type or character.
When is an eruption multiform?
When the lesions constituting the eruption are of two or more types or characters.
When are lesions said to be aggregated?
When they tend to form groups or closely-crowded patches.
When are lesions disseminated?
When they are irregularly scattered, with no tendency to form groups or patches.
When is a patch of eruption said to be circinate?
When it presents a rounded form, and usually tending to clear in the centre; as, for example, a patch of ringworm.
When is a patch of eruption said to be annular?
When it is ring-shaped, the central portion being clear; as, for example, in erythema annulare.
What meaning is conveyed by the term “iris”?
The patch of eruption is made up of several concentric rings. Difference of duration of the individual rings, usually slight, tends to give the patch variegated coloration; as, for example, in erythema iris and herpes iris.
What meaning is conveyed by the term “marginate”?
The sheet of eruption is sharply defined against the healthy skin; as, for example, in erythema marginatum, eczema marginatum.
What meaning is conveyed by the qualifying term “circumscribed”?
The term is applied to small, usually more or less rounded, patches, when sharply defined; as, for example, the typical patches of psoriasis.
When is the qualifying term “gyrate” employed?
When the patches arrange themselves in an irregular winding or festoon-like manner; as, for instance, in some cases of psoriasis. It results, usually, from the coalescence of several rings, the eruption disappearing at the points of contact.
When is an eruption said to be serpiginous?
When the eruption spreads at the border, clearing up at the older part; as, for instance, in the serpiginous syphiloderm.
Name the more common cutaneous diseases and state approximately their frequency.
Eczema, 30.4%; syphilis cutanea, 11.2%; acne, 7.3%; pediculosis, 4%; psoriasis, 3.3%; ringworm, 3.2%; dermatitis, 2.6%; scabies, 2.6%; urticaria, 2.5%; pruritus, 2.1%; seborrhœa, 2.1%; herpes simplex, 1.7%; favus, 1.7%; impetigo, 1.4%; herpes zoster, 1.2%; verruca, 1.1%; tinea versicolor, 1%. Total: eighteen diseases, representing 81 per cent. of all cases met with.
(These percentages are based upon statistics, public and private, of the American Dermatological Association, covering a period of ten years. In private practice the proportion of cases of pediculosis, scabies, favus, and impetigo is much smaller, while acne, acne rosacea, seborrhœa, epithelioma, and lupus are relatively more frequent.)
Name the more actively contagious skin diseases.
Impetigo contagiosa, ringworm, favus, scabies and pediculosis; excluding the exanthemata, erysipelas, syphilis and certain rare and doubtful diseases.
[At the present time when most diseases are presumed to be due to bacteria or parasites the belief in contagiousness, under certain conditions, has considerably broadened.]
Is the rapid cure of a skin disease fraught with any danger to the patient?
No. It was formerly so considered, especially by the public and general profession, and the impression still holds to some extent, but it is not in accord with dermatological experience.
Name the several fats in common use for ointment bases.
Lard, petrolatum (or cosmoline or vaseline), cold cream and lanolin.
State the relative advantages of these several bases.
Lardis the best all-around base, possessing penetrating properties scarcely exceeded by any other fat.
Petrolatumis also valuable, having little, if any, tendency to change; it is useful as a protective, but is lacking in its power of penetration.
Cold Cream(ungt. aquæ rosæ) is soothing and cooling, and may often be used when other fatty applications disagree.
Lanolinis said to surpass in its power of penetration all other bases, but this is not borne out by experience. It is an unsatisfactory base when used alone. It should be mixed with another base in about the proportion of 25% to 50%.
These several bases may, and often with advantage, be variously combined.
What is to be added to these several bases if a stiffer ointment is required?
Simple cerate, wax, spermaceti, or suet; or in some instances, a pulverulent substance, such as starch, boric acid, and zinc oxide.
Fig. 6.
FIG. 6.
A normal sweat-gland, highly magnified.(After Neumann.)
a, Sweat-coil:b, sweat-duct;c, lumen of duct;d, connective-tissue capsule;eandf, arterial trunk and capillaries.
What is hyperidrosis?
Hyperidrosis is a functional disturbance of the sweat-glands, characterized by an increased production of sweat. This increase may be slight or excessive, local or general.
As a local affection, what parts are most commonly involved?
The hands, feet, especially the palmar and plantar surfaces, the axillæ and the genitalia.
Describe the symptoms of the local forms of hyperidrosis.
The essential, and frequently the sole symptom, is more or less profuse sweating.
If the hands are the parts involved, they are noted to be wet, clammy and sometimes cold.
If involving the soles, the skin often becomes more or less macerated and sodden in appearance, and as a result of this maceration and continued irritation they may become inflamed, especially about the borders of the affected parts, and present a pinkish or pinkish-red color, having a violaceous tinge. The sweat undergoes change and becomes offensive.
Is hyperidrosis acute or chronic?
Usually chronic, although it may also occur as an acute affection.
What is the etiology of hyperidrosis?
Debility is commonly the cause in general hyperidrosis; the local forms are probably neurotic in origin.
What is the prognosis?
The disease is usually persistent and often rebellious to treatment; in many instances a permanent cure is possible, in others palliation. Relapses are not uncommon.
What systemic remedies are employed in hyperidrosis?
Ergot, belladonna, gallic acid, mineral acids, and tonics. Constitutional treatment is rarely of benefit in the local forms of hyperidrosis, and external applications are seldom of service in general hyperidrosis. Precipitated sulphur, a teaspoonful twice daily, is also well spoken of, combined, if necessary, with an astringent.
What external remedies are employed in the local forms?
Astringent lotions of zinc sulphate, tannin and alum, applied several times daily, with or without the supplementary use of dusting-powders. Weak solutions of formaldehyde, one to one hundred, are sometimes of value.
Dusting-powders of boric acid and zinc oxide, to which may be added from ten to thirty grains of salicylic acid to the ounce, to be used freely and often:—
℞ Pulv. ac. salicylici, ............................ gr. x-xxx.Pulv. ac. borici, ................................ ʒv.Pulv. zinci oxidi, ............................... ʒiij M.
Diachylon ointment, and an ointment containing a drachm of tannin to the ounce; more especially applicable in hyperidrosis of the feet. The parts are first thoroughly washed, rubbed dry with towels and dusting-powder, and the ointment applied on strips of muslin or lint and bound on; the dressing is renewed twice daily, the parts each time being rubbed dry with soft towels and dusting-powder, and the treatment continued for ten days to two weeks, after which the dusting-powder is to be used alone for several weeks. No water is to be used after the first washing until the ointment is discontinued. One such course will occasionally suffice, but not infrequently a repetition is necessary.
Faradization and galvanization are sometimes serviceable. Repeated mild exposures to the Röntgen rays have a favorable influence in some instances.
(Synonym:Miliaria crystallina.)
What is sudamen?
Sudamen is a non-inflammatory disorder of the sweat-glands, characterized by pin-point to pin-head-sized, discrete but thickly-set, superficial, translucent whitish vesicles.
Describe the clinical characters.
The lesions develop rapidly and in great numbers, either irregularly or in crops, and are usually to be seen as discrete, closely-crowded, whitish, or pearl-colored minute elevations, occurring most abundantly upon the trunk. In appearance they resemble minute dew-drops. They are non-inflammatory, without areola, never become purulent, and evince no tendency to rupture, the fluid disappearing by absorption, and the epidermal covering by desquamation.
Give the course and duration of sudamen.
New crops may appear as the older lesions are disappearing, and the affection persist for some time, or, on the other hand, the whole process may come to an end in several days or a week. In short, the course and duration depend upon the subsidence or persistence of the cause.
What is the anatomical seat of sudamen?
The lesions are formed between the lamellæ of the corneous layer, usually the upper part; and are thought to be due to some change in the character of the epithelial cells of this layer, probably from high temperature, giving rise to a blocking up of the surface outlet.
What is the cause of sudamen?
Debility, especially when associated with high fever. The eruption is often seen in the course of typhus, typhoid and rheumatic fevers.
How would you treat sudamen?
By constitutional remedies directed against the predisposing factor or factors, and the application of cooling lotions of vinegar or alcohol and water, or dusting-powders of starch and lycopodium.
Describe hydrocystoma.
Hydrocystoma is a cystic affection of the sweat-gland ducts, seated upon the face. The lesions may be present in scant numbers or in more or less profusion. They have the appearance of boiled sago grains imbedded in the skin; the larger lesions may have a bluish color, especially about the periphery. It is not common, and is usually seen in washerwomen and laundresses, or those exposed to moist heat. In some cases it tends to disappear during the winter months. There are no subjective symptoms.
Treatment consists of puncturing the lesions and application of dusting-powder. Avoidance of the exciting cause (moist heat) is important.
Describe anidrosis.
It is the opposite condition of hyperidrosis, and is characterizedby diminution or suppression of the sweat secretion. It occurs to some extent in certain systemic diseases and also in some affections of the skin, such as ichthyosis; nerve-injuries may give rise to localized sweat-suppression.
Treatment is based upon general principles; friction, warm and hot-vapor baths, electricity and similar measures are of service.
(Synonym:Osmidrosis.)
Describe bromidrosis.
Bromidrosis is a functional disturbance of the sweat-glands characterized by a sweat secretion of an offensive odor. The sweat production may be normal in quantity or more or less excessive, usually the latter. The condition may be local or general, commonly the former. It is closely allied to hyperidrosis, and may often be considered identical, the odor resulting from rapid decomposition of the sweat secretion. The decomposition and resulting odor have been thought due to the presence of bacteria.
What parts are most commonly affected in bromidrosis?
The feet and the axillæ.
What is the treatment of bromidrosis?
It is essentially the same as that of hyperidrosis (q. v.), consisting of applications of astringent lotions, dusting-powders, especially those containing boric acid and salicylic acid, and the continuous application of diachylon ointment. In obstinate cases weak formaldehyde solutions, Röntgen rays, and high-frequency currents can be tried.
Describe chromidrosis.
This is a functional disorder of the sweat-glands characterized by a secretion variously colored, and usually increased in quantity. It is, as a rule, limited to a circumscribed area. The most common color is red. The condition is probably of neurotic origin and tends to recur. (True chromidrosis is extremely rare; most of the cases formerly thought to be such are now known to be examples of pseudochromidrosis.)
Treatment should be invigorating and tonic, with special reference toward the nervous system. The various methods of local electrization should also be resorted to.
Mild antiseptic and astringent lotions or dusting powders should also be advised.
Red chromidrosisorPseudochromidrosisis a condition in which the coloring of the sweat occurs after its excretion and is due to the presence of chromatogenous bacteria which are found attached to the hairs of the part in agglutinated masses. The axilla is the favorite site. Treatment consists of frequent soap-and-water washings, and the application of boric acid, resorcin, and corrosive sublimate lotions.
Describe uridrosis.
Uridrosis is a rare condition in which the sweat secretion contains the elements of the urine, especially urea. In marked cases the salt may be noticeable upon the skin as a colorless or whitish crystalline deposit. In most instances it has been preceded or accompanied by partial or complete suppression of the renal functions.
Describe phosphoridrosis.
Phosphoridrosis is a rare condition, in which the sweat is phosphorescent. It has been observed in the later stages of phthisis, in miliaria, and in those who have eaten of putrid fish.
Synonyms:(Steatorrhœa; Acne sebacea; Ichthyosis sebacea; Dandruff.)
What is seborrhœa?
Seborrhœa is a disease of the sebaceous glands, characterized by an excessive and abnormal secretion of sebaceous matter, appearing on the skin as an oily coating, crusts, or scales.
In many cases the sweat-glands are likewise implicated, and the process may also be distinctly, although usually mildly, inflammatory.
At what age is seborrhœa usually observed?
Between fifteen and forty. It may, however, occur at any age.
Name the parts most commonly affected.
The scalp, face, and (less frequently) the sternal and interscapular regions of the trunk. It is sometimes seen on other parts.
What varieties of seborrhœa are encountered?
Seborrhœa oleosa and seborrhœa sicca; not infrequently the disease is of a mixed type.
What are the symptoms of seborrhœa oleosa?
The sole symptom is an unnatural oiliness, variable as to degree. Its most common sites are the regions of the scalp, nose, and forehead. In many instances mild rosacea coexists with oily seborrhœa of the nose.
Give the symptoms of seborrhœa sicca.
A variable degree of greasy scalines, which may be seated upon a pale, hyperæmic or mildly inflammatory surface.
The parts affected are covered scantily or more or less abundantly with somewhat greasy, grayish, or brownish-gray scales. If upon the scalp (dandruff,pityriasis capitis), small particles of scales are found scattered through the hair, and when the latter is brushed or combed, fall over the shoulders. If upon the face, in addition to the scaliness, the sebaceous ducts are usually seen to be enlarged and filled with sebaceous matter.
Describe the symptoms of the ordinary or mixed type.
It is common upon the scalp. The skin is covered with irregularly diffused, greasy, grayish or brownish scales and crusts, in some cases moderate in quantity, in others so great that large irregular masses are formed, pasting the hair to the scalp. If removed, the scales and crusts rapidly re-form. The skin beneath is found slate-colored, hyperæmic or mildly inflammatory, and exceptionally it has in places an eczematous aspect (eczema seborrhoicum). Extraneous matter, such as dust and dirt, collects upon the parts, and the whole mass may become more or less offensive. There is a strong tendency to falling-out of the hair. Itching may or may not be present.
FIG. 5.
Seborrhœa (Eczema Seborrhoicum).
Describe the symptoms of seborrhœa of the trunk and other parts.
Fig. 7.
FIG. 7.
A normal sebaceous gland in connection with a lanugo hair. (After Neumann.)
a, Capsule;b, fatty secretion;c,h, secreting cells;d, root of lanugo hair;e, hair-sac;f, hair-shaft;g, acini of sebaceous gland.
Seborrhœa corporis differs in a measure, in its symptoms, from seborrhœa of the scalp and is usually illustrative of the variety known as eczema seborrhoicum; it occurs as one or several irregular or circinate, slightly hyperæmic or moderately inflammatory patches, covered with dirty or grayish-looking greasy scales or crusts, usually moderate in quantity, and upon removal are found to have projections into the sebaceous ducts. It is commonly seen upon the sternal and interscapular regions. It rarely exists independently in these regions, being usually associated with and following the disease on the scalp. It may also invade the axillæ, genitocrural, and other regions.
What is the usual course of seborrhœa?
Essentially chronic, the disease varying in intensity from time to time. In occasional instances it disappears spontaneously.
Give the cause or causes of seborrhœa.
General debility, anæmia, chlorosis, dyspepsia, and similar conditions are to be variously looked upon as predisposing.
In some instances, however, the disease seems to be purely local in character, and to be entirely independent of any constitutional or predisposing condition. The view recently advanced that the disease is of parasitic nature and contagious has been steadily gaining ground.
What is the pathology of seborrhœa?
Seborrhœa is a disease of the sebaceous glands, and probably often involving the sweat-glands also; its products, as found upon the skin, consisting of the sebaceous secretion, epithelial cells from the glands and ducts, and more or less extraneous matter. Not infrequently evidences of superficial inflammatory action are also to be found, and it is especially for this type that the name eczema seborrhoicum is most appropriate. In long-continued and neglected cases slight atrophy of the gland-structures may occur.
With what diseases are you likely to confound seborrhœa?
Upon the scalp, with eczema and psoriasis; upon the face, with lupus erythematosus and eczema; and upon the trunk, with psoriasis and ringworm.
As a rule, the clinical features of seborrhœa are sufficiently characteristic to prevent error.
What are the differential points?
Eczema, psoriasis, and lupus erythematosus are diseases in which there are distinctinflammatory symptoms, such as thickening and infiltration and redness; moreover, psoriasis, and this holds true as to ringworm also, occurs in sharply-defined, circumscribed patches, and lupus erythematosus has a peculiar violaceous tint and an elevated and marginate border. A microscopic examination of the epidermic scrapings would be of crucial value in differentiating from ringworm.
Quite frequently, especially in the interscapular and sternal regions, the segmental configuration constitutes an important feature of seborrhœa—of the eczema seborrhoicum variety.
What is the prognosis in seborrhœa?
Favorable. All types are curable, and when upon the non-hairy regions, usually readily so; upon the scalp it is often obstinate. Relapses are not uncommon.
In those cases of seborrhœa capitis which have been long-continued or neglected, and attended with loss of hair, this loss may be more or less permanent, although ordinarily much can be done to promote a regrowth (seeTreatment of Alopecia).
How would you treat seborrhœa of the scalp?
By constitutional (if indicated) and local remedies; the former having in view correction or modification of the predisposing factor or factors, and the latter removal of the sebaceous accumulations and the application of mildly stimulating antiseptic ointments or lotions.
What constitutional remedies are commonly employed?
The various tonics, such as iron, quinine, strychnia, cod-liver oil, arsenic, the vegetable bitters, laxatives, malt and similar preparations. The line of treatment is to be based upon indications.
How do you free the scalp of the sebaceous accumulations?
In mild types of the disease shampooing with simple Castile soap (or any other good toilet soap) and hot water will suffice; in those cases in which there is considerable scale-and crust-formation the tincture of green soap (tinct. saponis viridis) is to be employed in place of the toilet soap, and in some of these latter cases it may be necessary to soften the crusts with a previous soaking with olive oil.
The frequency of the shampoo depends upon the conditions. In mild cases once in five or ten days will be sufficiently frequent to keep the parts clean, but in those cases in which there is rapid scale-or crust-production once daily or every second day may at first be demanded.
Name the most effectual applications in seborrhœa capitis.
Sulphur, ammoniated mercury, salicylic acid, resorcin, and carbolic acid.
Sulphur is used in the form of an ointment, from twenty grains to one drachm in the ounce. Ammoniated mercury, in the form of an ointment, ten to sixty grains to the ounce. Salicylic acid, either alone as an ointment, ten to thirty grains to the ounce; or it may
often be added with advantage, in the same proportion, to the sulphur or ammoniated mercury ointment above named. Resorcin, either as an ointment, ten to thirty grains to the ounce, or as an alcoholic or aqueous lotion, as the following:—
℞ Resorcini, ....................................... ʒj-ʒiss.Ol. ricini, ...................................... ♏xxx-fʒij.Alcoholis, ...................................... f℥iv. M.
Carbolic acid, to the amount of ten to thirty grains, can be added to this. If an aqueous lotion is desirable, then in the above formula the oleum ricini is replaced with glycerine, and the alcohol with water; three to five minims of glycerine in each ounce is usually sufficient, as a greater quantity makes the resulting lotion sticky. Petrolatum alone, or with 10 to 30 per cent. lanolin, is usually the most satisfactory base for the ointments. In some cases of the inflammatory variety the skin is found quite irritable, and the mildest applications are at first only admissible.
How are the remedies to be applied?
A small quantity of the lotion, ointment, or oil is gently applied to the skin; when to the scalp, a lotion or oil can be conveniently applied by means of an eye-dropper. In the beginning of the treatment an application once or twice daily is ordered; later, as the disease becomes less active, once every second or third day.
How is seborrhœa upon other parts to be treated?
In the same general manner as seborrhœa of the scalp, except that the local applications must be somewhat weaker. The several sulphur lotions employed in the treatment of acne (q. v.) may also be used when the disease is upon these parts. In obstinate patchy cases occasional paintings with a 20 to 50 per cent alcoholic solution of resorcin is curative; following the painting a mild salve should be used.
(Synonyms:Blackheads; Flesh-worms.)
What is comedo?
Comedo is a disorder of the sebaceous glands, characterized by yellowish or blackish pin-point or pin-head-sized puncta or elevations corresponding to the gland-orifices.
At what age and upon what parts are comedones found?
Usually between fifteen and thirty, and upon the face and upper part of the trunk, where they may exist sparsely or in great numbers. They are occasionally associated with oily seborrhœa, the parts presenting a greasy or soiled appearance.
Exceptionally they occur as distinct, and usually symmetrical, groups upon the forehead or the cheeks. On the upper trunk so-called double and multiple comedo have been noted—the two, three, or even four closely-contiguous blackheads are, beneath the surface, intercommunicable, the dividing duct-walls having apparently disappeared by fusion.
Describe an individual lesion.
It is pin-point to pin-head in size, dark yellowish, and usually with a central blackish point (hence the nameblackheads). There is scarcely perceptible elevation, unless the amount of retained secretion is excessive. Upon pressure this may be ejected, the small, rounded orifice through which it is expressed giving it a thread-like shape (hence the nameflesh-worms).
What is the usual course of comedo?
Chronic. The lesions may persist indefinitely or the condition may be somewhat variable. In many instances, either as a result of pressure or in consequence of chemical change in the sebaceous plugs or of the addition of a microbic factor, inflammation is excited and acne results. The two conditions are, in fact, usually associated.
Fig. 8.