The the description of the Emperor Augustus given by the Roman historian Suetonius (born about A.D. 69) includes the following observations: "His body is said to have been marred by ... a number of hard, dry patches suggesting ringworm, caused by an itching of his skin and a too vigorous use of the scraper at the baths." Later the writer adds that Augustus was subject to "certain seasonal disorders: In early spring a tightness of the diaphragm; and when the sirocco blew, catarrh."
Mier, P. D.
Br. J. Dermatol. 92 (1975), 359.
CLINICAL CONCEPT OF THE NATURE OF ATOPIC DERMATITIS
The above quotation is thought to be the earliest description of atopic dermatitis and points out the association of this skin disorder with respiratory allergies. It is probably a genetic disorder of the skin, inherited in association with the tendency to develop allergic respiratory conditions but not in itself a primary allergic disease.
The preceding article, by Weston and Huff, discusses current theories of pathogenesis, but it is necessary to present a purely clinical concept of the nature of the disorder (Table 1). At the center is genetically abnormal skin, characterized by intense itching and a tendency to eczematization and lichenification and influenced by a wide variety of factors that, acting on the genetically abnormal skin, exacerbate the natural pruritic tendency and result in eczematization and/or lichenification.
Figure 1. "Allergic shiners" and Morgan's folds.
There is no long-term prospective study to give us accurate data on the frequency of atopic dermatitis in the general population. It is estimated that as many as 20 per cent of the population have atopy and that about one-third of these have atopic dermatitis. The disorder is commonly seen in the offices of dermatologists and pediatricians.
Figure 2. The transverse nasal crease.
Figure 3. Mother and daughter with transverse nasal crease.
A family history of atopic dermatitis, asthma, or hay fever is obtained in a high percentage of patients with atopic dermatitis. Such a history is therefore of importance in establishing the diagnosis. There is good evidence for the genetic nature of these diseases, although the mode of inheritance has not been established. It is likely that the inheritance is multigenic, with the atopic diathesis giving rise to respiratory allergies and the genetically abnormal skin being due to separate but closely linked genes.
In addition to a history of respiratory allergy in the patient or his relatives, certain clues to the allergic tendency can be noted on first inspection of the patient or his accompanying parent or siblings. There is frequently a distinct pallor of the face with "allergic shiners," or blue shadows under the eyes. A double pleat or fold (Morgan's fold or Pennies' fold) may be present on the lower eyelid, extending from the medial epicanthus (Figure 1). The child who has had allergic rhinitis for some time usually has a transverse line on the nose, which results from the constant rubbing and pushing upward of the tip of the nose - the "allergic salute" (Figures 2 and 3).
The primary lesions of atopic dermatitis are not very obvious. Much of what is thought of as the typical appearance of these patients is the result of secondary phenomena. The most important primary "lesion" is the pruritus. Jacquet once said that this disease is not a rash that itches but, rather, an itch that rashes.
In addition to the itchiness of the skin, there are other primary lesions. Dryness of the skin, due to retention of insufficient amounts of water in the stratum corneum, is an important feature and contributes to the pruritus. The other common primary feature of the atopic skin is the presence of "goose bumps" over much of the truncal skin (Figure 4). These are tiny papules at all the hair follicle orifices. In some areas, particularly the flanks and the dorsa of the upper arms, these papules become larger and hyperkeratotic - so-called follicular hyperkeratosis, or keratosis pilaris (Figure 5). In areas where these hard papules are scratched or rubbed, they become confluent and develop into the skin thickening known as lichenification (Figure 6).
Figure 4. The "goose bump" appearance of atopic skin.
Figure 5. Follicular hyperkeratosis on lower back of a child with atopic dermatitis.
Figure 6. The confluence of hyperkeratotic papules to form a lichen itied plaque.
Figure 7. Dry, chapped, erythematous face of a child with early infantile atopic dermatitis.
Most of the appearance commonly referred to as eczema is secondary, due to trauma to the skin resulting from scratching and rubbing, with the almost invariable secondary infection. The crusted, oozing skin so often seen in the infant or young child with atopic dermatitis is thus scratched, infected skin.
Figure 8. The scratched, secondarily infected face of a more advanced case of infantile eczema.
Atopic dermatitis rarely appears before two months of age. The infantile stage of the disease tends to be more exudative and inflammatory than the later stages. In this age group the lesions are often characterized by erythema, vesiculation, and crusting.
At the onset in infancy, there is usually a mild erythema of the cheeks with a dry, chapped appearance (Figure 7). This may then spread to involve most of the face and forehead with exudative papules and vesicles, which become scratched, irritated, and secondarily infected (Figure 8). Scaling of the scalp, leading to scratching and crusting, frequently follows; in many infants scattered lesions appear elsewhere on the body, especially the extensor surfaces of arms and legs. The eruption in the infantile stage tends to improve gradually, but the common statement that it clears by one and one-half to two years of age is overly optimistic.
Figure 9. The more advanced follicular papules of the childhood stage.
The childhood stage can follow the infantile stage without interruption, or it can appear after a variable period of more or less complete remission. This phase of the disease is much less inflammatory and is characterized more by dryness of the skin. It is in this childhood stage that the small, more or less skin-colored papules at the follicular orifices become more apparent (Figure 9). In areas where considerable scratching occurs, these papules tend to become larger, somewhat crusted, and confluent, producing lichenified plaques with surrounding discrete papules (Figure 10). The flexor areas, particularly those of the anticubital and popliteal fossae, as well as the flanks and back of the neck, are favored locations in this stage. Again, complete remission can occur at any time before the prepubertal age, or the eruption can merge imperceptibly with the succeeding adolescent and adult phases.
In the third stage of atopic dermatitis, there is an even greater tendency to confluence of papules with formation of large plaques, especially in the anticubital and popliteal fossae. These plaques are usually red to brown and are surrounded by excoriated papules (Figure 10). The neck, eyelids, wrists, hands, and feet are also common areas of involvement (Figure 11). Since itching is severe, there are often excoriations and resulting infection with crusting and exudation. In fact, the results of scratching are evident at all stages of the disease (Figure 12).
Figure 10. The adolescent or adult phase of atopic dermatitis, showing the confluence of follicular papules to form lichenified plaques.
The infant with atopic dermatitis is restless, irritable, and constantly scratching. This results in an unhappy family situation, maternal rejection, and paternal resentment. In spite of this environment of tension, the infant's psychologic development proceeds normally or even in an accelerated fashion. In early childhood, these children become active and intelligent. However, as adolescence approaches, severely afflicted patients become resentful and hostile. In a study of adults with atopic dermatitis, Bird found a high frequency of suppressed aggression; he suggests that the inability to overtly express aggression is an important personality difficulty in the patient with this disease.
Since pruritus is a primary feature of atopic dermatitis, nonitchy eruptions should not be considered in establishing the diagnosis. Certain associated features are of help and should always be sought when atopic dermatitis is being considered. The allergic facies - consisting of facial pallor, "allergic shiners," Morgan's folds, and the transverse nasal crease - has already been discussed (Figures 1, 2, and 3). In addition, white dermographism is often elicited on stroking the skin (Figure 13).
Figure 11. Hand eczema in an adolescent patient with atopic dermatitis.
Figure 12. Secondarily infected atopic dermatitis in the classic distribution.
During infancy there are a number of rather rare systemic diseases in which eruptions indistinguishable from atopic dermatitis can occur. Examples of these diseases are Aldrich's syndrome, Hurler's mucopolysaccharidosis, phenylketonuria, and ectodermal dysplasia. These disorders can be distinguished by recognition of their associated systemic manifestations and appropriate laboratory tests.
The distinction between seborrheic dermatitis and infantile atopic dermatitis can be difficult. The seborrheic dermatitis of infants is characterized by thick, yellow, greasyfeeling scaling of the scalp and dermatitis of the postauricular folds as well as the intertriginous areas. No lichenification develops, and pruritus is mild or absent. Atopic dermatitis is always very itchy.
Figure 13. White dermographism.
Lichen simplex chronicus may resemble atopic dermatitis but is sharply localized to one or two areas. The diagnosis of eczema tous contact dermatitis requires skill in history taking and appropriate patch testing.
The most important complication of atopic dermatitis is the occurrence of Kaposi's varicelliform eruption, which is due to the increased susceptibility of these patients to either herpes simplex or vaccinia virus. Because of the seriousness of this complication, all patients with atopic dermatitis should be isolated from contact with persons recently vaccinated or infected with acute herpes simplex.
Because of the chronic excoriation of the skin, patients with atopic dermatitis are frequently infected with either Staphylococcus aureus or betahemolytic streptococci. These infections may be acute and apparent, or they may smolder in an occult manner and increase pruritus if not treated.
A much less common but serious complication is the development of cataracts in patients with longstanding chronic atopic dermatitis. For this reason, all atopic children should have regular eye examinations.
Psychologic. The physician is advised to spend considerable time with the patient in order to convey a clear understanding of the nature of atopic dermatitis. He should try to dispel the idea that eczema is primarily an allergic disease and should make the patient aware of the many contributing factors. During this initial discussion, the alert physician will make an effort to detect evidence of emotional factors that might be contributing to the problem.
Infection. When first seen, most patients with atopic dermatitis have secondary infection with either streptococci or staphylococci. This is manifest as oozing, crusting, and assuring of the skin. This infection must be adequately treated before other steps can be effective. Locally applied antibiotics are of very little use in this situation. Systemic antibiotic therapy should be given for 10 days to two weeks to adequately eliminate the secondary infection. Most useful for this purpose is erythromycin, 1 gm. per day in divided doses.
Clothing. The patient with eczema has a tremendous tendency to itch, and anything that irritates the skin will cause him to scratch. He should therefore avoid irritating clothing, especially woolens. Cotton and some of the softer synthetics are preferable for the atopic patient. It must be remembered that wool-upholstered chairs are also a source of irritation.
Sweating. Another important factor in the stimulation of pruritus is anything that will increase the tendency to sweat. Atopic dermatitis is also associated with a degree of sweat retention that will produce itching. Therefore, excessive clothing, high environmental temperatures, and overabundance of activity will increase the sweat retention difficulty and promote itchiness.
Antipruritic sedation. Since the worst scratching is done at night, it is wise to give these patients nighttime sedation until their skin condition is under control. Diphenhydramine (Benadryl®), given in doses of 25-50 mg. about one hour before bedtime, is an effective antipruritic sedative. If emotional tension is an important contributing factor, it is also advisable to give a daytime medication, such as hydroxyzine hydrochloride (Atarax®), 25 mg. three times daily. Systemic corticosteroids should rarely be given. Proper attention to all aspects of these cases should make the use of these agents, with the attendant side effects, unnecessary in this chronic disorder.
Diet. Dietary management is helpful only in the first year or two of life. Since cow's milk is the most common allergen in infancy, eliminating it from the baby's diet will often make the dermatitis more easily controllable. In the older patient food elimination is less often of help, although a complete dietary history and use of a food diary will occasionally bring out revealing information.
Hyposensitization. Skin tests and hyposensitization therapy are of very little use in the treatment of patients with atopic dermatitis, since there seems to be little relationship between the positive tests and causation of flares of the dermatitis.
When eczema is first seen in the acute phase with inflammation, oozing, and crusting, it is important to recognize that secondary infection is present, and systemic antibiotic therapy must be promptly instituted (see above). Reduction of inflammation and removal of crusts and exudate are best done with intermittent cold, wet dressings applied by the open method. Two or three layers of gauze, kerlix, or linen are thoroughly moistened with Burow's solution and loosely applied to the involved areas. One-half to one hour of application four times daily is usually sufficient, with remoistening by complete removal of the dressing every 10 to 15 minutes to prevent drying and sticking. Burow's solution, 1:40, is prepared by dissolving one tablet or packet (Domeboro® tablets and packets) in a quart of cool tap water. Wet compresses should not be used for longer than three days.
At this point, or if the patient is first seen in the dry, itchy phase of the disease, one may proceed with the modified Scholtz regimen, the prime feature of which is the complete avoidance of bathing with water. The dry skin of atopic dermatitis is due to a lack of sufficient water in the stratum corneum. The drier the skin, the greater the pruritus. Washing with water removes the watersoluble substances that retain the water in the horny layer, resulting in increased dryness and itchiness after bathing.
The modified Scholtz regimen is instituted as follows:
1. There should be no bathing with either soap or water. The only exception to this no-bathing rule is the use of a moist washcloth to cleanse the groin and axillary areas.
2. The entire skin surface is cleansed at least twice daily with a nonlipid cleansing lotion consisting primarily of cetyl alcohol, sodium laurel sulfate, propylene glycol, and water (Cetaphil® lotion). The lotion is applied liberally and rubbed in until it foams. It is then gently wiped off, leaving a film of the lotion on the skin. The film aids the retention of water in the horny layer of the skin.
3. No oily or greasy lubricants or topical preparations are allowed.
4. Inflamed or pruritic areas of the dermatitis are treated by topical application of fluorinated corticosteroids in either a solution or cream formulation, not an ointment base. One may use triamcinolone (Kenalog®) or fluocinolone (Synalar®) four times daily.
All acutely inflamed areas can be quickly cleared with the topical steroid preparation. In most instances, if the entire program is followed, clearing occurs in two or three weeks. After the acutely inflamed areas have responded, it is possible to maintain the improvement by adhering to the no-bath routine and Cetaphil® cleansing. The topical steroid is then needed only occasionally when there is a brief flare of the dermatitis.
When the skin has remained clear of eruption for several months, a brief cool bath is allowed about once or twice monthly, always followed by a liberal application of the lipid-free lotion. Most patients are able to tolerate a brief, not hot, bath as often as once weekly after they have remained clear for several months. It is essential that they learn never to bathe more often than once weekly and that they continue indefinitely to use the Cetaphil® lotion daily for cleansing and lubrication.
Bird, B. Certain observations upon the relationship of anger and eczema. Am. Pract. Dig. Treat. 9 (1958). 929.
Chenowith, B. R., and Lobitz, W. C1 Jr. Atopic dermatitis. In Demis. D. J., et al. (eds.). Clinical Dermatology, Volume 3. Unit 13, Section 2. Hagerstown, Md.: Harper & Row, 1976.
Jacobs, A. H. Atopic eczema. In Gellis. S. S., and Kagan, B. M. (eds.). Current Pediatric Therapy. Fifth Edition. Philadelphia: W. B. Saunders Company, 1973. p. 752.
Jacobs, A. H. Management of atopic dermatitis in childhood. In Ruiz-Maldonado, R. (ed.). Pediatric Dermatology. Mod. Probi. Paediatr. 17 (1975), 149.
Jacobs, A. H. Management of children with atopic dermatitis. Cutis 10 (1972), 587.
Rajka. G. Atopic Dermatitis. Philadelphia: W. B. Saunders Company, 1975.
CLINICAL CONCEPT OF THE NATURE OF ATOPIC DERMATITIS