(Eczema seborrhoicum, Seborrhoeic dermatitis)
Definition. An inflammatory disease usually commencing upon the scalp with a tendency to downward extension, characterized by greasy scaliness.
Symptoms. This is a condition in which the seborrheic element is primary, followed by an eczematous inflammation. It nearly always begins as a seborrhea of the scalp, although it may start from the same condition in the axillary or genito-crural regions, front of chest or very rarely elsewhere. The condition is insidious in its development and spreads by peripheral extension, although it may remain stationary for a long time and then suddenly become active, spreading in an absolutely irregular manner. The itching is dependent upon the degree of inflammation but is usually very mild. The lesions are few or many, discrete or aggregated, or by coalescence form variously shaped patches.
This disease presents a number of clinical forms which vary simply in degree. The simplest variety, or squamous type, presents a more or less diffused scaliness on a yellowish or slightly reddened skin. It is little more than a simple seborrhea plus the mildest type of irritation although crusts may form from the seborrheic secretion and appear a soft grayish-white or yellowish-brown in color. The next type is more intense, presenting round or oval, pink or red, sharply defined, superficial macules. Reddish papules may also be found discretely located or aggregated. These macular and papular lesions, by peripheral extension and central involution, form circinate, gyrate or band-like lesions, with scales that may be scanty or abundant, of a gray or white color. The surface of these lesions may be moist, in fact, distinctly catarrhal from the oil and sweat secretions and a serous exudate. In the third degree the disease is pronouncedly inflammatory and the itching so intense as to cause scratching. The redness is more pronounced and the greasy discharge more abundant. While the first type is the most common, all degrees of the disease may coexist, or appear in slow or rapid succession on the same person.
On the scalp, where the disease usually begins, it is chiefly located on the vertex or occiput, presenting a grayish-white scaling upon a pale red and dry skin (pityriasis capitis). As a result of this condition the hairs become loose, lusterless and scant (alopecia pityroides). Moist lesions may occur and at the margins of the forehead and occiput, well-defined curved bands or lines covered with scales or fatty crusts are frequently seen (corona seborrhoica). As the process spreads downward over the forehead, temples and back of neck, a distinct redness is still visible covered with the fatty scales and moist lesions. The face, especially the middle third, including the nasolabial fold, may be involved without extension from the scalp but it is usually secondary. A butterfly distribution over the nose and cheeks, similar to lupus erythematosus, is not uncommon. Any degree of the disease may exist in these locations and the backs of the ears are often involved with complicating fissures. When the auditory canal is affected, the meatus may become filled with fatty accumulations and the hearing impaired. If the lips are affected, they become dry and stiff, with crusts which tend to separate and form fissures, exposing the moist denuded surface. Eyebrows, mustache and beard may be affected similarly to the scalp. When the eyelids and the outer and inner angles of the eyes are involved, the secretions from the eyes serve to indefinitely prolong the condition.
When the axillary, anal, genitocrural and interdigital regions are involved, red masses with little crusting and scaling, except on the peripheral margins, will be noted. These forms may extend on the contiguous surfaces until pronounced ringworm-like lesions with central clearing can be seen. Two surfaces of affected skin thus involved coming in contact will stimulate an erythema intertrigo, eczema marginatum or ringworm. The heat, moisture and friction in these neighborhoods largely account for the marked inflammatory features. On the trunk, the initial lesions may be small papules or macules, more or less covered with scales. Over the sternum and between the scapuli the papular form is most common. By peripheral growth or coalescence, patches with central involution develop and may cause figurate lesions of any degree. On other parts of the body the lesions are more apt to be round or oval macules with less tendency to form patches. When the umbilicus is involved, the process is nearly eczematous because the inflammation, exudation and itching are all pronounced. It is well to note that seborrheic dermatitis often coexists with such diseases as psoriasis, syphilis, rosacea, acne and sycosis.
Etiology and Pathology of Seborrhea and Dermatitis Seborrhoica. Seborrheic diseases are met with in both sexes and at all ages. Exclusive of the early infantile types, the diseases are most frequently found between the ages of twelve and thirty, when the glandular structures are most active. All causes that tend to lower the systemic or cutaneous vitality may be said to predispose to this disease. Among the constitutional conditions may be mentioned syphilis, gout, chlorosis, struma, chronic alcoholism, malnutrition following acute fevers, menstrual or digestive disorders, chronic constipation, sedentary habits or the excessive use of tobacco. Locally, the wearing of stiff, heavy hats, the want of ordinary cleanliness, irritating soaps or patent tonic remedies, heavy woollen underwear and retained sweat are all etiological. Local heat, friction, moisture and other irritations no doubt are largely responsible for the transition of a non-flammartory to an inflammatory type of seborrhea.
Pathologically, seborrhea is a functional disorder of the sebaceous glands, showing an overproduction of normal sebum and a dilation of the sebaceous-duct openings. The simpler forms show changes in the secretion as to quantity, fluidity, inspiration and at times, a tendency to decomposition and subsequent inflammation. Inflammation is probably present in all except the simple oily varieties and the severer form must be regarded as a dermatitis due to irritations of all sorts, developing in the absence of normal resistance of the epidermis. The various predisposing general or local conditions make possible this lowered resistance. It is now generally conceded that seborrheic diseases are parasitic in nature and contagious, but it is not fully determined just what the causal microorganism or organisms may be. In any event, they are only feebly contagious and require a favorable soil. The germ has been variously described as a morococcus, a diplococcus or a micro-bacillus (Sabouraud). Further study is needed to exactly define the value of these parasites as etiological agents.
Diagnosis. The characteristic greasiness of the skin and hair in seborrhea oleosa makes the diagnosis of this form easy; seborrhea sicca usually exists on the scalp and presents greasy scales with no inflammation; but dermatitis seborrhoica might be mistaken for any of the following:
Eczema presents ill-defined redness, infiltration, exudation, dark non-greasy crusts, and marked itching. Squamous eczema does not have greasy scales nor does it freely shed them from the surface and there is no tendency to crescentric or annular formations.
Psoriasis may exist on the scalp but usually characteristic lesions will be found upon the extensor surfaces, covered by dry pearly-white scales. Rounded, circumscribed patches, markedly red skin beneath the scales and a tendency to persist indefinitely and resist treatment are further characteristics of psoriasis. Seborrheic dermatitis and psoriasis often coexist.
Pityriasis rosea seldom attacks the scalp. Its lesions are oval, covered with fine non-greasy scales and the centers often clear up but remain fawn colored. Itching is variable but the disease runs a typical course of from six to ten weeks.
Tinea circinata and tinea tonsurans may be diagnosed by the microscope. On the scalp, lesions of ringworm are circular, less diffuse than those of seborrhea and present broken hairs in the affected area. No forms of ringworm show greasy scales and most will give a history of contagion.
Impetigo contagiosa, when it has reached the crusting stage, might be mistaken for seborrheic crusts but it is an acute affection, usually occurring in children, only lasts one or two weeks if properly treated, and presents discrete vesicopustules, which by coalescence and rupture form bulky crusts.
A pustular syphilid might resemble the accumulated scales of seborrhea but the history of the case, such as the primary sore, mucous patches, other syphilids, and the purulent secretion found on the removal of the crusts in the pustular form should establish the diagnosis.
Lupus erythematosus may resemble seborrheic dermatitis when located on the face, but its patches are better defined, their color is a deeper red, their scales are very adherent and dry and, besides, lupus is a new-growth, followed by scarring, while seborrhea is a functional inflammatory disorder leaving the skin unchanged.
Prognosis. Most cases are curable although they may be persistent and have a tendency to recurrence. When the scalp is involved, except in the infantile type, it should always be borne in mind that the resulting baldness may be permanent.
Treatment. Physiological measures are often necessary because, despite the probable parasitic cause, the underlying predisposing factors are those most apt to cause a continuance of the disease. The correction of faulty digestion and the relief of constipation are most essential. In fact, any disorder which might have a causal relation to the cutaneous disturbance should be regulated so as to prevent a continuance. In this particular, a daily cold bath with or without the addition of rock salt has often worked well. Exercise, sleep, clothing and the most private personal habits may need regulation. Lactobacillin in some form is often useful to relieve intestinal fermentation. Spinal stimulation by galvanic or high-frequency currents may be useful and the latter agent, applied directly to the involved area, will often obviate the need of strong local treatment because, besides the removal of the irritating crusts and scales, stimulation is often desired. The X-rays are frequently curative if applied in repeated small doses and this measure alone is superior to any of the older local methods. Gentle frictions with some plain oil or fat will loosen the scales which may then be removed. Cleansing with a non-irritating soap and hot water will likewise clean the surface which, after drying, should be anointed with some non-medicated oil or fat.
The eczematous forms frequently need medicated soaps containing sulphur, resorcin or salicylic acid, or tincture of green soap may be applied to the surface with sufficient hot water to make a lather. If these methods of cleansing are not sufficient, one of the following lotions may be used: sulphur 1 dram, alcohol and rose water each 2 ounces, glycerin 1/2 ounce; sulphuric ether and biborate of soda each 3 drams dissolved in 10 ounces of distilled water; or mercuric chlorid solution (1:1000). Delicate or sensitive skins take kindly to alkaline aqueous solutions as cleansers, such as ammonia, potassium carbonate, sodium bicarbonate and borax. These may be followed by some mild antiparasitic ointment in place of the non-medicated oils. Ointments are seldom used for the oily form of seborrhea or in the types involving the genitals, umbilicus and axillae. In these cases the lotions mentioned above or finely powdered boric acid (1part to 4 of starch or talc), powdered salicylic acid (1 part to 9 of starch) or compound stearate of zinc may be used. If ointments are desired or necessary, any one of the following may prove useful, using a base of cold cream, fresh lard, vaseline or zinc oxid ointment: sulphur, 40 to 60 grains to the ounce; resorcin, salicylic acid, betanaphthol, ammoniated mercury or calomel, 5 to 40 grains to the ounce. Frequently in seborrhea of the scalp, less often in other types, the functional tone of the skin may be improved by the addition of strong agents, such as the following; resorcin, the tinctures of capsicum, cantharis or nux vomica, or the fluid extracts of ergot or pilocarpin. These may be incorporated in a simple ointment in the proportion of 10 to 60 drops to the ounce or better, in many cases, lotions embodying the same amounts of these substances may be dissolved in 1 dram of boroglycerid and 7 drams of rose water. Occasionally severe, persistent types have been benefitted by the hypodermic use of an autogenous culture or a stock vaccine of acne bacilli.
My chief enthusiasm for the internal pathogenetic treatment of these cases is based upon the fact that again and again clinic patients who would not, or could not, carry out the proper local treatment, have been cured by the properly indicated remedy. In all cases it is fair to suppose that this means is most effective as an adjuvant, if not the chief method of treatment. See Agaricus, Am. mur., Bryonia, Calcarea acet., C. carb., Chelidonium, Colchicum, Hydrastis, Kali brom., K. mur., K. sulph., Kreosotum, Mercurius viv., Mez., Nat. arsen., N. mur., Acid nitricum, Pet., Phosphorus, Selenium, Sepia., Sul. and Vinca.