Diaper Dermatitis: From "A" to "Pee"

ABSTRACT: Rash in the diaper area is usually caused by irritant contact dermatitis. Inflammation in the diaper area may also be the result of other dermatologic conditions, infections, nutritional and immune deficiencies, metabolic disorders, malignancy, or child abuse. Because newborns as young as 1 week experience skin compromise in the diaper area, it is never too early to begin educating caregivers about how to prevent irritant contact dermatitis. Basic treatment principles for diaper dermatitis include frequent diaper changes or inspection for soiling; frequent cleansing of the diaper area with water and a soft cloth; and use of topical barriers with water-impermeable substances. Powders are best avoided. Use topical low-potency corticosteroids sparingly and for no longer than 2 weeks. Use of topical antifungal-corticosteroid products in the diaper area is contraindicated. Consider applications of a topical antifungal if diaper dermatitis persists longer than 3 days. Consider further evaluation with laboratory studies and dermatology referral if diaper dermatitis persists beyond 2 to 4 weeks despite aggressive treatment.

The "A" in the title stands for acrodermatitis enteropathica, an uncommon underlying cause of diaper dermatitis (DD). The "Pee," the colloquial term for urine, is probably the most common irritant (along with feces) that contributes to the breakdown of skin in the diaper area.

As the title implies, this article details the everyday to the rare causes of DD and their treatment. Recommendations are based on a review of the current literature and on our clinical experience.

EPIDEMIOLOGY

DD is an inflammatory reaction of the skin in the area of the body that is covered by a diaper. Ward and colleagues¹ classify DD as the most common dermatologic disorder of infancy in the United States; it is diagnosed in more than 1 million office visits per year.

DD is most likely to occur in the first 2 years of life. However, children of any age who wear diapers can suffer from it. By 1 week of life, most newborns have some evidence of skin compromise in the diaper area.² The frequency and severity increases by postnatal weeks 2 and 3. Akin and colleagues³ reported that approximately one third of 1500 infants examined in a 5-year period showed some degree of skin irritation in the diaper area, and about 6% experienced severe dermatitis.³ Data collected from hospitalized children revealed that approximately one quarter of patients displayed some skin breakdown--most commonly in the buttocks, perineum, and occiput.⁴

Pediatricians and family medicine physicians diagnose and treat the vast majority of affected children.¹ Patients rarely receive (or need) care from a dermatologist for this problem unless the dermititis is recalcitrant.

ETIOLOGY

Rash in the diaper area is usually caused by irritant contact dermatitis. Prolonged exposure to urine and feces triggers the skin breakdown. These bodily fluids increase the skin's wetness, and fecal enzymes (urease, proteases, lipases) contribute to maceration. Diaper wearing is associated with an elevated skin pH, which further activates fecal enzymes.

Although wetness is one of the factors involved in the development of diaper rash, it is not fully understood why a fetus is able to develop and maintain intact skin while immersed completely in amniotic fluid. Visscher and colleagues² explain that the stresses on the skin postnatally--including changes in ambient temperature, alterations in dryness and wetness, application of topical preparations, and exposure to the frictional and occlusive forces of diapers--contribute to the breakdown of the perineal skin. Irritant contact dermatitis (probably caused by the glue components in the securing bands of diapers) occurs in the diaper closure area as erythema in a triangular shape accompanied by edema, vesicles, and erosions.⁵

Infection with Candida albicans and disease states associated with frequent waste elimination--such as acute gastroenteritis, short-gut syndrome, or persistent urinary leakage--can aggravate and perpetuate DD. Ferrazzini and colleagues⁶ found that colonization of the perianal area by Candida species was significantly more frequent in children with DD than in children with healthy skin (75% vs 19%, respectively). Staphylococcus aureus colonization was not more frequent, however.

Children taking oral antibiotics are at particular risk for a candidal diaper rash. Infants experience up to a 14-fold increase in the density of C albicans and a decline in endogenous bacterial flora in the perineum after 10 days of therapy with oral amoxicillin.⁷

If not caused by irritant contact dermatitis, inflammation in the diaper area may be the result of other dermatologic conditions, infections, nutritional and immune deficiencies, metabolic disorders, malignancy, or child abuse. Dermatologic causes include allergic contact dermatitis, seborrheic dermatitis, psoriasis, and granuloma gluteale infantum.

Children with atopic dermatitis are prone to DD, but the moist diaper area is often spared. Allergic contact DD can occur secondary to the blue, pink, and green dyes used in some disposable diapers.⁸ Epidermolysis bullosa, hemangiomas, and (rarely) pyoderma gangrenosum can lead to ulcerative DD in infancy.⁹ Chang and colleagues¹⁰ recommend that infantile granular parakeratosis be included in the differential diagnosis of DD. This idiopathic disorder of keratinization is characterized by linear plaques and scales localized to the inguinal folds or under pressure points produced by the diaper.

Along with Candida, infectious agents that can produce dermatologic abnormalities in the diaper area include S aureus, group A streptococci, Coxsackievirus, human papilloma- virus (HPV), herpesvirus, Sarcoptes scabiei, and congenital Treponema pallidum. Although the majority of children in the diaper-wearing age group (younger than 2 years) acquire anogenital HPV as a result of non-sexual horizontal transmission, every case deserves at least a consideration of possible sexual abuse.¹¹ Ecthyma gangrenosum may occur secondary to various bacteria and fungi in debilitated infants. Recalcitrant DD may be caused by HIV.

Rare in the United States, dietary deficiencies of protein, biotin, and zinc can cause DD. A chronic scaly DD may be a symptom of acrodermatitis enteropathica--a rare autosomal recessive disease in which intestinal zinc-binding ligands are absent, leading to zinc deficiency. An "acrodermatitis-like" rash has been described secondary to urea cycle defects.¹²

Along with congenital and acquired immune deficiencies, another rare condition included in the differential diagnosis of persistent DD is Langerhans cell histocytosis (LCH). If the clinical scenario is suggestive, unusual causes (Table 1) should be considered in chronic cases of DD that are resistant to therapy.

CLINICAL PRESENTATION

Irritant contact DD begins as acute erythema on the convex skin surfaces of the pubic area and buttocks (Figure 1). The skin folds are spared. Jacquet erosive dermatitis--a severe form of irritant DD--is characterized by punched out ulcers with elevated borders.⁹ Findings indicative of secondary infection with yeast include shiny, erythematous patches that involve the skin folds and the presence of small erythematous papules (satellite lesions). Thrush and erythema of the neck folds or axilla may also be present. Studies indicate that when DD persists for 3 or more days, C albicans is isolated in up to 80% of affected infants (Figure 2).¹³

S aureus infection presents as bullous impetigo, characterized by scattered vesicles, bullae, and denuded areas of skin. Other infectious and chronic dermatologic disorders have their own distinctive physical findings (see Table 1) but may be difficult to clinically distinguish from one another in some cases.

Recalcitrant skin breakdown or unusual eruptions in the diaper area signal a possible underlying systemic disorder, especially when systemic symptoms are also present. Head and truncal lesions; growth delay; and GI, neurologic, and developmental abnormalities are most worrisome.

Zinc deficiency and urea cycle defects cause orofacial lesions in addition to those in the diaper area. Systemic signs and symptoms of nutritional deficiencies may also include failure to thrive (FTT), irritability, diarrhea, alopecia, and developmental or behavioral abnormalities. Severe nonresolving DD, along with generalized eczema, FTT, and recurrent dermatologic and other systemic infections may be part of the clinical presentation of an underlying immune deficiency. An example is Wiskott-Aldrich syndrome--an X-linked immune disorder--which needs to be considered in boys with severe DD, eczema, persistently draining ears, and thrombocytopenia.

The seborrheic-like rash associated with LCH consists of scaly papules on the face, axilla, trunk, and groin. Signs and symptoms of other organ dysfunction will be evident in multisystem LCH.

Child abuse and neglect can present in multiple ways. If the cause is not obvious, signs of poor bodily and dental hygiene, multiple bruises, and unusual markings in the diaper area may provide the clinical clues.

DIAGNOSIS

The history of present illness, associated symptoms, and physical examination findings usually provide enough information to make a clinical diagnosis of irritant contact DD. As with the diaper area, the mouth must be inspected for thrush and the skin and nails examined for other lesions. A rash that persists for more than 3 days and is accompanied by involvement of the skin folds and/or thrush probably indicates a secondary yeast infection. Potassium hydroxide slide preparations of the skin or mouth scrapings are not routinely done or necessary to diagnose a candidal infection; if obtained, however, they would reveal several hyphae. If the lesions are vesicular and lead you to suspect herpes infection, a Tzanck smear or viral culture can be obtained.

If the diaper rash does not resolve or improve after 2 weeks of treatment (Table 2), suspect noncompliance and/or reassess the history. The presence of exacerbating factors--such as diarrhea or oral antibiotics--may explain persistent symptoms.

If you have been assured that compliance is adequate, consider the possibility of another secondary infectious process. Bacterial infections can be diagnosed via cultures obtained from swabs of the perianal area or lesion discharge. Patients with unexplained, nonresolving yeast infections may need to be evaluated by an immunologist for suspected chronic mucocutaneous syndrome or other immune disorder.

Microscopic examination of scrapings from linear lesions in suspected scabies may reveal evidence of this mite infection. This is typically a low-yield test in a child, however.

Consider further evaluation when DD persists beyond 1 month despite aggressive treatment for irritant, bacterial, or yeast dermatitis. If other worrisome signs, symptoms, or physical examination findings (ie, facial involvement, neurologic abnormalities, growth delay) are present, begin the workup sooner. Chosen on a case-by-case basis, a general illness laboratory screen may include a complete blood cell count; tests of liver and renal function; and measurement of levels of zinc, biotin and biotinidase activity, ammonia, amino acids, and urinary organic acids. When the serum zinc level is low, a further workup must ensue to determine its cause (eg, acrodermatitis enteropathica, inadequate intake, cystic fibrosis).

To diagnose LCH and many other dermatologic conditions, histologic examination of a skin biopsy specimen is necessary. Except for skin biopsy, all of the studies involved in the workup for DD can be ordered by the pediatrician. Otherwise, ideally, a pediatric dermatologist should be consulted--especially in recalcitrant cases or if patch testing for allergic contact dermatitis is being considered. Other empiric treatments may be tried (as described below) on an individual basis. Alternatively, use of all topical agents and scented or dyed products can be stopped for 1 to 2 weeks in lieu of a biopsy. If these empiric interventions fail, a biopsy may then be necessary.

A biopsy may also be needed to determine the cause of frequent unexplained recurrences.

TREATMENT

Prevention is the best medicine. Educating the caregivers about the cause of irritant contact DD may go a long way in preventing skin breakdown. Because newborns already experience skin compromise in the diaper area by 1 week of age,² the clinician cannot begin too early to discuss diaper rash prevention.

Frequent diaper changes--or at least inspection and palpation of the diaper to determine if soiling has already occurred--may be necessary every hour. Newborns, for example, may urinate as often as every 30 minutes or so. Breast-fed babies in the first several weeks of life also defecate multiple times per day.

Clinicians should show parents this technique for checking disposable diapers: while avoiding contact with the baby's skin, pinch the outside of the disposable diaper over the genital area to determine whether the diaper feels "squishy." If it does, the gel material in the diaper has absorbed wetness and soiling has occurred.

Vigilant diaper changes prevent prolonged exposure to wetness and fecal enzymes, thereby disallowing skin hyperhydration and breakdown. Allowing maximum diaper-free time for air drying is helpful, but not very practical.

The cure for irritant contact DD is elimination of the diaper. Because this is also impractical, however, the goal of treatment is to limit the amount of time the skin is exposed to the environment that promotes the production of DD. Many commercial products, which have been studied to various degrees, are available and may or may not aid in the prevention and treatment of DD.

DIAPERS

Disposable diapers are probably superior to reusable cloth diapers in reducing the incidence and severity of DD.^14,15 Fiorillo¹⁶ reported that Jacquet erosive dermatitis is found almost exclusively in babies who are diapered in cloth.

There are several brands of disposable diapers that vary in cost and style. There is an advantage to using superabsorbent diapers that contain an absorbent gelling material that extracts the moisture from the affected area.¹⁷ A disposable diaper has also been manufactured that continuously administers a petroleum-containing emollient to the skin; this product is associated with significant reductions in DD.¹⁸ Other advancements in diaper technology include the development of "breathable" disposable diapers³ and the creation of a water-impermeable membrane inserted into diaper layers.¹⁹

The choice of a brand of diaper often depends on parental preference and cost. It is reasonable to recommend a trial use of the least expensive brand--especially if caregivers adhere to proper diapering hygiene. If an allergic reaction to dye is suspected, dye-free diapers should be chosen.⁸

The environmental effect of the use of disposable versus cloth diapers is a topic of public interest. Prasad and colleagues¹⁹ concluded that the debate will continue as the impact of the crowding of landfills with disposable diapers is weighed against the excessive water consumption and detergent release into the environment produced by the washing of reusable diapers.

"BABY WIPES"

Cleansing and drying the affected area is important to wash away corrosive enzymes. Gentle washing with water applied via a soft cloth or poured over the diaper area can aid in the cleaning process. Harsh soaps must be avoided and a non-detergent cleanser used instead.

Many caregivers clean the child with moist towelettes (or "baby wipes") manufactured specifically for use in the diaper area. Most children--even those with atopic dermatitis--tolerate baby wipes very well.²⁰ Odio and coworkers²¹ provided evidence that disposable wipes were gentler to irritated skin than water applied via a cotton washcloth. However, "baby-wipe dermatitis" can occur secondary to preservatives or fragrances in the moist towelettes, which have also been shown to cause hand eczema in adult users of the product.²² As with the diapers, caregivers can choose a brand to use on a trial basis as tolerated.

TOPICAL PREPARATIONS AND BARRIERS

Although some infants who are prone to irritation in the diaper area may benefit from the empiric application of a barrier, others rarely experience skin breakdown and do not need routine empiric barrier application. Dozens of topical preparations in various vehicles are available commercially, and most water-impermeable barriers contain zinc oxide and petroleum.

Dimethicone is another well-tolerated water-repellant substance found in diaper rash preparations. Many products contain vitamins (A, D, and E) for skin conditioning. There is no evidence that supports or refutes the use of topical vitamin A preparations in DD.²³

Because they effectively adhere to the skin, ointments and pastes that contain water-impermeable ingredients and other soothing substances (eg, lanolin, mineral oil, wax, olive oil are particularly effective at protecting the skin in patients with high-output states, such as diarrhea. Some ingredients (eg, rosin and dyes) may exacerbate the DD, so labels must be inspected for potential irritants. Keep in mind that not all ingredients are listed on the label; unlisted ingredients may be an exacerbating factor. Barriers can also be used on a trial basis as tolerated.

Other products, not routinely used in general practice, are available for the treatment of severe DD associated with debilitating conditions. Topical 4% sucralfate in aqueous cream has been found to heal compromised skin in chronic irritant DD.²⁴ Sucralfate--an oral treatment for GI ulcers--acts as a mechanical barrier through its electrostatic properties that interact with proteins at the ulcer site.²⁴ Over-the-counter liquid antacids have also been recommended for use in the eroded diaper area. These are applied 4 times daily, allowed to dry, and then covered with another barrier preparation.¹⁶ Along with topical zinc oxide oil, commercial barrier films have been shown to be effective in patients with DD secondary to incontinence.²⁵

POWDERS

Talcum powder and cornstarch may reduce friction, absorb moisture, and eliminate chafing in the diaper area. These products are not routinely recommended, however, because of the risk of aspiration pneumonia. Talc is the more notorious agent for causing respiratory disease, but severe pneumonitis following inhalation of cornstarch powder during diapering has also been reported.²⁶ If powder is used, the caregiver should pour a small amount of it into his or her own hand and then gently pat the affected diaper area so that minimal excess is present--well away from the baby's airway. These products must be kept out of the reach of other children also.

There are many other diaper rash products available without this potential risk. Advise parents to avoid powders.

ANTIFUNGALS

If DD has been present for more than 3 days or is particularly severe, add a topical antifungal medication. Nystatin is the most commonly prescribed, but the azoles (clotrimazole and miconazole and ciclopirox topical suspension (0.77%) are also effective and should be continued for 3 days after the rash has resolved.^27,28 Eradication of C albicans usually takes less than 1 week.²⁹

Although typically regarded as an effective anti-S aureus agent, mupirocin has also been found to be an excellent antifungal agent when applied 3 or 4 times daily.²⁹ If thrush is also present, oral nystatin is recommended--along with treatment of the breast-feeding mother, and cleaning of pacifiers, plastic nipples, and teething toys. Al-Waili³⁰ has described the mycological benefits of a topical mixture of honey, olive oil, and beeswax.

ANTIBACTERIALS

It may not always be easy to discern the presence of a secondary bacterial infection. Therefore, an empiric 1-week trial of topical mupirocin is reasonable in persistent cases--especially because this medication is generally safe, well tolerated, and has the added benefit of antifungal activity. Oral antibiotics may be necessary in the child with atopic dermatitis who is prone to widespread S aureus infection.

CORTICOSTEROIDS

Low-potency corticosteroids (class 6 or 7 only) need to be used in the diaper area very judiciously--and only in moderate to severe cases--to reduce inflammation and discomfort. Low-strength hydrocortisone (1%) and desonide are appropriate choices for the primary care physician. A minimal amount of medication should be applied once or twice daily for 3 days initially, and for no longer than 2 weeks. Warn caregivers about the adverse effects of prolonged and excessive use of topical corticosteroids in the occluded diaper area. Occlusion increases systemic absorption of these active medications. The development of cushingoid features and drug-induced adrenal suppression are major complications that will occur if the corticosteroid is applied inappropriately.^31,32 Dermal atrophy is another potential adverse effect, as is the development of granuloma glu- teale infantum.

Application of antifungal-corticosteroid combination products (such as clotrimazole-betamethasone dipropionate) in the diaper area should be absolutely avoided. The high-potency, fluorinated, halogenated corticosteroids in these combination products carry too great a risk to the diapered child. These combination products are contraindicated in the treatment of DD.

ANTI-CALCINEURINS

The immunomodulators tacrolimus and pimecrolimus may be effective in DD, but are not approved for use in children younger than 2 years. These agents have not specifically been tested for use in DD. However, it may be tempting to try these medications because they do not cause skin atrophy and do not affect the hypothalamic-pituitary-adrenal axis.

An alert by the FDA in March 2005 warned patients and health care providers of a potential cancer risk with the use of these agents and stated that tacrolimus and pimecrolimus should only be used as second-line treatment for approved conditions (atopic dermatitis).³³ These agents must be avoided in children younger than 2 years.³³

OTHER

If an underlying dermatologic or systemic disorder is diagnosed, many of the treatments described above may be needed to help heal the skin in the diaper area. However, treatment specific to the underlying cause is the most important part of management (eg, zinc supplementation for zinc deficiency).

Along with monitoring the diaper area, the primary care pediatrician needs to coordinate care with the necessary specialists to ensure comprehensive care of the child