It is important to have contact der­matitis in mind. If you do have it in mind you will see a good many chil­dren in whom you are reasonably sure that the trouble has been coming from the outside. Determination of the exact cause is, however, a very differ­ent matter, and often is impossible. The general principle of treatment, therefore, is to keep the skins of these children covered up, and in contact with nothing, if possible, except old white cotton cloth. This is never allergenie. The local treatment is the same as for atopic dermatitis. (See atopic dermatitis.)

Sensitization and ensuing dermatitis from drugs contained in local applica­tions to the skin are very common in adults – I doubt if they are as common in infants and children. I have used coal tar for literally thousands of pa­tients and ammoniated mercury in hundreds, and have seen just three cases of sensitization to tar and two to mercury. However, the indiscriminate use of all sorts of salves, often bought “over the counter” without prescrip­tion and without having any idea of what they contain, is to be condemned. If one is fearful that a child may be sensitive to some drug, it is a simple matter to do a patch test with it be­fore using it on the eczema. Some of the more common sensitizing drugs are mercury, resorcin, sulfur, benzocaine, various proprietary “antifungus” preparations, salicylic acid, es­sential oils (used in some proprietary salves to make them smell better), penicillin, and sulfadiazine.

Contact dermatitis from shoes is not uncommon and is often wrongly thought to be a fungus infection. It is caused more often from the cements, asphalts, or other adhesives that are used in the linings of shoes than from anything to do with the leather itself. It is usually seen on the upper surface of the foot and toes, and not between the toes, which are protected from con­tact with the causative chemical. Fungiis infection is likely to occur be­tween and underneath the toes. When there is contact dermatitis from shoes it is quite a problem to know what kind of shoes to wear. Inasmuch as the trouble usually comes from vari­ous parts of the lining, unlined shoes of the moccasin “loafer” type or sandals made entirely of leather are the best shoes to wear. If the trouble is coming from the leather, sneakers can be worn. It is also quite possible that one pair of shoes will cause dermatitis, and another will not.

Fig. 22.-Contact dermatitis from shoe lin­ings, probably from the cement. Local treat­ment : zinc oxide paste, followed by Swartz’s ointment or medium strength tar paste. (From Brennemann’s Practice of Pediatrics.)

Ammonia dermatitis is common in babies of the diaper age and is caused by the breaking down into ammonia of the urea in the urine on the diaper by bacteria from the bowel. Ammonia dermatitis is a classical example of dermatitis from a primary irritant- there is no allergic sensitization. There may be erythema with moderate peel­ing, papules, bullae, or actual ulceration, depending upon the concentra­tion of ammonia which contacts the skin. There is always in the diffuse erythematous type a sharp line of de­marcation following the line of the diaper. The diagnosis is made by the appearance and by the strong am­monia smell, particularly in the morn­ing, after the baby has had his wet diapers on all night.

I recommend that all young pedi­atricians read Cooke’s^* original paper in which he showed the cause of the trouble and recommended the first satisfactory treatment for it. He suggested that the diapers be soaked in mercuric chloride or in boric acid solution. The first works practically every time, the second is not much good. The diapers are washed and rinsed as usual, then soaked for an hour in a white enamel bucket three-fourths full of water in which one 7.3 grain tablet of mercuric chloride has been dissolved; then they are wrung out and allowed to dry with­out rinsing. This is the best treat­ment for ammonia dermatitis: I do not think any of the newer antisep­tics that have been recommended are nearly as good. In the last few years it has been shown that most children with acrodynia have been exposed to mercury, and two cases have been re­ported following the use of mercuric chloride as a diaper disinfectant.¹⁰ This must be very unusual, because for a long time most pediatricians have used Cooke’s method, and acrodynia, in New England at any rate, is a rare disease. I have used this treat­ment for thirty-four years, since Cooke’s original paper was published, for every baby that I have seen with ammonia dermatitis. There has been no acrodynia, no other child in the family has eaten the mercury tablets, and practically every patient treated has been cured entirely and com­pletely.

*Cooke, J. V.: Etiology and Treatment of Ammonia Dermatitis of the Gluteal Region in Infants, Am. J. Dis. Child. 23: 481, 1921.

I am inclined to think that in chil­dren the clothing is the most common cause of contact dermatitis. It may be difficult or impossible, however, to determine what constituent of, or addi­tive to, the cloth is causing the trouble. Wool is a common cause of eczema-it can work either by inhalation or by contact. Such eczema is best classed under atopic dermatitis. (See atopic dermatitis.) Many dyes can cause con­tact eczema, and I have been pretty sure many times that the dye in clothes was causing the trouble, but have obtained few positive patch tests to the dyed fabric. Cotton cloth, when nothing has been added to it, is not allergenic.

However, practically all cotton garments have had “finishes” applied to them as mordants, for softening or for stiffening, or for making the material look or feel better. There are a large number of these “finishes,” of different chemical composition. The most common are starches, gums, resins, detergents, and bleaching agents. If eczema appears on the trunk after wearing a new undershirt, or on the upper legs or buttocks after wearing new shorts, it is likely that the cause may be one of these cotton “finishes.”

Plant Dermatitis

In some parts of the country, derma­titis from weeds,⁷ particularly rag­weed, is common in adults; it is not common in children. The dermatitis is caused by contact with the oil con­tained in the leaves, stems, and pollen. Patch tests are positive. Eczema from pollen is common in children, but this is of the atopic variety, and is caused by inhalation of the pollen. Patch tests are negative, scratch or intracutaneous tests are positive, with the protein fraction of the pollen. Ordi­nary “poison ivy” is, of course, common in children almost everywhere.

Treatment of Poison Ivy

1. Prophylactic.-There is much in the literature about this; some think that it is worthless, some that it is of great value. I have not had enough experience with prophylactic treat­ment for poison ivy to form any worth-while conclusions. From what little I have seen, from what I have read, and from the information gathered by word of mouth from others who have used it more than I, it would seem that it is worth while, but not reliable. It can be done by inoculation or by iugestion. Which is the better of the two methods, I do not know.

‘Shelmire, Bedford: Contact Dermatitis From Weeds: Patch Tests With Their Oleo Resins, J. A. M. A. 113: 1085, 1939

a. Inoculation: “Ivyol”*: 0.5 c.c. is injected intramuscularly each week for four weeks before the start of the ivy season.

b. Ingestion: “Rhus Tox”t: Start in the late spring with 5 drops three times a day in half a glass of water; increase 3 drops each day up to 15 drops three times a day. Give this dose every day all summer, f

2. Local Treatment.-Poison ivy dermatitis is a self-limited disorder; it will get well by itself if you do not try to do too much to it. In its more severe forms, however, it is what I would call a ”very bad disease,” and may require a good deal of treatment.

a. Under no circumstances give any inoculation with poison ivy extract. This is likely to do more harm than good if given when ivy dermatitis is present.

b. If the dermatitis is oozy, use wet dressings of 1 to 10,000 potassium permanganate solution, or Burow’s solution, 1 tablespoonful to a glass of water.

c. If not oozy, apply the following lotion several times a day:

(Rx)      Acid carbolic     gr. xx Zinc oxide 3 ss Lime water § viii

d. After the acute stage has passed, use Lassar’s paste for a few days- then a mild salve such as zinc oxide ointment (U.S.P.) or Acid Mantle Creme.§

e. If there is much itching at night, give chloral hydrate,!] °r Nembutal or Seconal.

f. In severe cases use cortisone by mouth, 100 mg. a day to children over 6 years, 75 mg. a day to those under 6 years, until the worst is over, then gradually reduce the dose and soon discontinue it.

* Sharp & Dohme, Philadelphia.

tThe  National   Drug-  Co.,  Philadelphia. tit there   is  any  burning- or itching-  about the rectum, the dose should be reduced. §Dome   Chemicals   Inc.,   New  York. USquibb’s.

I am writing especially for pediatri­cians. I will therefore start this sec­tion by suggesting to them that it would be best if they discarded the idea that all eczematous skin eruptions in infants and children are caused by what they eat and cured by removing some food from the diet.

Contact dermatitis is the most com­mon eczema of adults. It is not so common in infants and children be­cause they are not exposed to the multiplicity of skin sensitizers that adults are. In 156 consecutive cases of eczema from my office records, in patients between the ages of 1 and 17 years, I made the diagnosis of con­tact eczema thirty-one times. I have no figures for young babies. I doubt if the percentage would be so high; however, it is common enough so that the possibility of it should always be borne in mind.

Contact dermatitis may be caused by irritation of the skin by substances which cause irritation in all persons (primary irritants) or by substances which irritate only when the patient has become allergically sensitized to them. The epidermis is the seat of sensitization-there are, so far as is known, no circulating antibodies, no hereditary predisposition as there is in atopic dermatitis, and no associa­tion, except fortuitously, with asthma or hay fever. Contact dermatitis is an episode, atopic dermatitis a dis­ease ; the episode is not uncommonly superimposed upon the disease and a contact dermatitis may be added to

an existing atopic dermatitis. I think it is probable that those who have atopic dermatitis are somewhat more likely to develop contact dermatitis than are those who do not have it. Not all would agree with this.

The causes are innumerable: metals, dyes, essential oils, plastics, cosmetics, turpentine, plant oils, drugs-indeed, chemicals of almost any sort, organic or inorganic, which come into contact with the skin.

The most important things in the treatment of contact dermatitis are:

(1) To be on the lookout for it, and to realize that it occurs at any age. To decide whether or not you are dealing with a contact dermatitis.

(2) To get at the cause, if possible, and remove it.

(3) To keep the skin entirely pro­tected from contact with anything which might do it harm.

(4) Local treatment with various lotions, pastes, or ointments: the same as for atopic dermatitis. (See atopic dermatitis.)

The appearance of the skin in acute contact dermatitis varies all the way from simple erythema, with slight scaling, to the most intense vesicula-tion, or even bullae. If such eczema appears rather suddenly on a previ­ously healthy skin, particularly if it appears in one place on an exposed surface, contact dermatitis should always be considered. In chronic cases there is a good deal of thicken­ing and even lichenification, so that the appearance may closely resemble that of atopic dermatitis. The borders are not sharp, and the trouble may, in a short time, spread from the point of original contact, sometimes by transfer with the fingers, probably sometimes through the blood stream.

Fig. 20.-Contact dermatitis from Metaphen nose drops.     Patch test to  mercury  strongly posi­tive.     (From Lirennemann’s Practice of Pediatrics.)

Fig.  21.-Contact   dermatitis   from ammoniated   mercury   ointment.     Local   treatment:      zinc oxide paste   (U.S.P.).     (From  Brennemann’s  Practice  of Pediatrics.)

It is usually not hard to be reasonably sure from the history and from the appearance and location of the erup­tion that a contact eczema is present, but determination of the cause is quite another matter. All too com­monly it is never determined. I have done a great many patch tests in children when I knew that the eczema was of external origin, and have seen few positive tests. I think the prob­able reason is that in many of these children the degree of sensitization is not great enough to cause dermatitis unless the contact is prolonged and there is a certain amount of trauma of the skin as well (rubbing). The extreme degree of sensitivity that is so often seen in adults is not so com­monly seen in children, although I see no reason why, if they were sensi­tized to some of the things that cause so much trouble in adults (such as paraphenylenediamine or various metallic salts), they should not give as well-marked patch tests as the adults do. The children shown in Figs. 20 and 21, who were sensitive to mercury, gave well-marked positive patch tests.

Some of the things to suspect are as follows: “baby oils,” most of which contain essential oils (aromatic amines), salves or lotions which have been used in treatment, toilet water or other cosmetics, shampoos, turpen­tine, detergents or bleaching powders, dyes or “finishers” in clothes (very important), plastics, lacquered toilet seats, plants, and toys. I have never seen contact dermatitis from soap,* although it undoubtedly does occur. I have seen proved contact dermatitis in children from the following things: dyes, mother’s cosmetics, primrose, ivy, the leaves of the white mulberry bush, plastics, toilet seat lacquer, ammoniated mercury, tar, sulfur, Sopronol, a proprietary shampoo, furniture polish, hair tonic, turpentine, creosote, and tincture of green soap.

*Except from tincture of green soap, due to   the   lavender   it   contains.

Note: I    have    used    the    words    “eczema”    and “dermatitis”   interchangeably.