Definition. – A chronic tubercular new-growth of the skin and mucous membranes, characterized by papules, nodules and infiltrated patches and usually terminating in ulceration and scarring, less commonly in absorption, exfoliation and atrophy.
Symptoms. – Lupus is the most important form of tuberculosis of the skin but it is not so common as scrofuloderma. The many clinical forms, for which qualifying terms have been invented, are one and all types of the same pathological process. The typical eruption consists of one or several, pin- head-to pea-sized, soft, flat papules of a dull brownish or yellowish-red color. These may be scarcely perceptible to the touch or elevated but, in either instance, the color does not quite disappear on pressure. The term “apple-jelly” has been applied to this papule because of its color and softness which permits of ready indentation by pressure with a blunt instrument. This simple type may remain throughout its course but usually the papules develop into pea-sized or larger nodules or tubercules, which become aggregated in variously sized and shaped patches and by coalescence form dark-red, raised, soft patches. The center of these patches, through involution or ulceration, becomes scarred leaving an atrophic area surrounded by an elevated red border which, if it continues to increase peripherally, may cover a wide portion of the surface (lupus serpiginosus). Gyrate lesions may develop from the coalescence of irregular or rounded patches.
Reactive changes in the tissues around the lupus infiltrate may take the form of thickening, edema, hypertrophy, hyperplasia or lymphangitis, which were called by the older writers lupus hypertrophicus, lupus elephantiaticus, lupus papulosus, lupus edematosus, etc. If a fatty or cheese degeneration ensues, the softening resulting therefrom causes an ulcer (lupus exedens, lupus exulcerans) which is a more common termination than the absorption of the growth leaving a small, scaly, scarred surface (lupus exfoliativus). The typical lupus ulcer is irregular in outline with a well-defined thin edge, shallow and reddish margin, a grayish or dull-reddish, granulating or hemorrhagic floor, with little pain or sensitiveness to pressure, and a marked absence of induration or hardness before cicatrization ensues. Advances of the disease and subsequent destructive processes may be superficial (lupus superficialis) or it may be deep and destroy fibrous, muscular, cartilaginous and even bone tissue. Both superficial and deep processes may go on at the same time (lupus vorax). Fortunately the acutely destructive forms of lupus are very rare and probably due to some secondary infection or to a peculiar idiosyncrasy of the individual attacked.
Lupus vulgaris ordinarily occurs in a single patch but it may present multiple lesions, either at one time or at long or short intervals. The distribution may be wide and general (lupus disseminatus) but it should be noted that it is most likely to occur on the warmer parts of the skin. In Austria, extensive lupus is not rare but in America it is seldom found in more than one region of the body and very rarely shows any tendency to become symmetrical. Lupus is more apt to be active in childhood and a variable or spontaneous disappearance after a definite course may ensue, leaving behind atrophic scars. Fresh lesions may develop in these sites or in new patches many years later, and thus the disease may falsely appear as beginning in middle or later life. It often persists from childhood to old age, never quite disappearing. Exacerbations and remissions in the activity of the process are common in this variable and chronic disease. It seldom appears to have any effect on the general health, except in an indirect way or in unusual cases. Subjective sensations are usually absent, although coexisting dermatitis of the affected or surrounding tissues may cause moderate heat, burning, itching and tension.
Fig. 132. – Lupus vulgaris of forty years’ duration, involving one half of the face and neck. These lesions entirely disappeared after long continued X- raying.
The favorite seat of the lupus is the face, especially the nose, cheeks and ears. It often begins at the alae of the nose and progressively destroys the skin and cartilage, giving to the nose a hacked-off appearance. in rare instances it may extend all over the nose, up into the eye, gradually destroying the bone, eyelids and eyeball. In some advanced cases crusts and papillary growths give an appearance of increased size to the nose, but on the removal of these, the cutaneous parts of the nose and cartilages may be found nearly or quite destroyed. Other parts of the face are seldom attacked primarily but often secondarily. The extremities are by no means a rare location for lupus, especially the spreading form. When the lower limbs are involved there may be present, as a result of inflammation and contraction in the tissues, pronounced venous and lymphatic stasis with consequent edema, thickening and hypertrophy amounting to a condition of elephantiasis. Lupus of the trunk is apt to be superficial but more extensive than in other parts. Over the nates, papillary, elephantiac or the ulcerating serpiginous types are apt to develop. Lupus of the genitals is rare in either sex and usually the result of extension from nearly lesions.
Fig. 133- Lupus vulgaris of moderate involvement and intensity. Duration, four years.
Lupus of the mucous membranes may be primary or secondary as compared with that of the skin but the latter sequence is the rule. The mucous surfaces may be involved by the single or multiple, well-defined, granulating patches or papillary hypertrophies of a whitish, grayish or reddish color. These are of variable size and change slowly into ulcerative or cicatricial processes. The buccopharyngeal and the laryngeal membranes are more often affected than the tongue but even laryngeal lupus is quite rare.
Etiology and Pathology. – Considerably over one half of the cases develop before the age of fifteen years and females are more prone to the disease than males. All causes that tend to lower ordinary vitality, such as poor hygiene, general debility, filth, or insufficient food, together with any break in the continuity of the skin, are etiological factors. Besides, tubercular disease is often present in other members of the family and the patients themselves may have a tubercular affection of the other organs. It is probable that the mode of infection by the tubercle bacilli in lupus is either by direct inoculation from without or by indirect inoculation by continuity from deeper tubercular foci. My experience would lead me to believe that the latter is the more common mode of infection.
Fig. 134. – Lupus vulgaris of eight years’ duration, showing facial patch cured by X-raying.
Fig. 135. – Showing other healed lesions on the left side of the face and neck. Same as Fig. 135.
It is commonly believed that there are two fairly distinct processes occurring in lupus, namely the neoplastic caused by the irritation of the tubercle bacillus, and the suppurative, from the presence of the staphylo-coccus aureus, the latter being found in the ulcerative forms and not in the dry type. In any case the bacilli are extremely scant, in fact can scarcely be found in many patches of lupus. The corium is the starting point of the disease which progresses upward and an accumulation of cells, situated about the capillaries and lymphatic channels constituting a growth of the adventitia of these vessels, constitutes the primary nodules of granulation tissue. On a histopathological basis, Unna divides lupus into two principal forms, the circumscribed or nodular and the diffuse. In the former the tubercles are inclosed in a limiting collagenous capsule, while in the latter the infiltration is spread evenly along the lymph spaces, causing a diffuse infiltration. A connective tissue growth often replaces the granular and cellular infiltration, so changing the normal structure of the skin as to cause its destruction and atrophy. Pressure from beneath may provoke a rupture of the epidermis and permit pus infection which results in ulceration.
Diagnosis. – Lupus vulgaris usually begins in childhood or youth, pursues an indolent painless course, is frequently situated on the face, and presents a deep red color, soft papules or jelly-like nodules, and frequently presents other signs of tuberculosis.
The tubercular syphilids usually originate in adult life, show a history of primary infection and traces of other lesions, run a rapid course, their nodules are firm, their ulcers present a copious discharge with bulky greenish crusts, are wider, deeper, with more sharply cut edges and are apt to be multiple, while the scars are whitish, smooth, and soft, and healing readily occurs under the use of specific medication.
Scrofuloderma is apt to show linear scars, caseous glands, sinuses with more ulceration and undermining of the skin than occurs in lupus, but an absence of the lupus nodule. Both of these conditions may coexist and as they are closely related, a positive diagnosis is not important.
Epithelioma is a disease of advanced life and often develops from an irritation of warts, moles and similar growths. It is painful and while limited to a smaller area, its progress is frequently more rapid and the glands more involved. A skin cancer may originate in a chronic lupus patch, hence the two diseases may coexist. The smooth floor and indurated border of the rodent ulcer, typical of epithelioma, is a distinct point in differentiation.
Lupus erythematosus usually appears after puberty, is symmetrical in distribution, is superficial in nature, without soft nodules or tendency to suppurate. If the adherent crusts are removed, the widened opening of one or more sebaceous ducts will be revealed corresponding to little projections on the under surface of the crust.
Squamous eczema and dermatitis seborrhoica will invariably show some exudation with a tendency to itching but lack the apple-jelly nodules, persistent course or tendency to scar formation.
The early stage of tubercular or mixed leprosy presents a more generalized eruption, usually begins later in life and has anesthetic, macular patches.
Prognosis. – Lupus is always a chronic disease, rebellious to treatment and, though it does not thrive in this country as elsewhere and is less virulent and progressive with us, there is always the danger of relapses. It seldom destroys life and though the danger of secondary tubercular infection is possible, it is not great. Scarring is to be expected in all cases. The prospects of a cure depend upon the age of the subject, the duration and extent of the disease, and the persistent cooperation of the patient. Relatively the prognosis is good as compared with tuberculosis of other organs.