Introduction
Eruptions in the diaper region have diverse origins. This chapter will review eruptions, both common and uncommon, that have major findings in the diaper area not only in neonates but also in young infants ( Box 17.1 ). Many of the conditions listed in Chapter 10 (vesicles, pustules, bullae, erosions, and ulcerations) may be seen or arise in the diaper region. There are diseases that may also involve other areas of the body and coincidentally affect the diaper area that are mentioned but not discussed in detail in this chapter. Tables 17.1–17.3 describe the clinical setting, morphology, distribution, and best method for diagnosing the major conditions causing diaper area eruptions in neonates and infants.
Inflammatory conditions
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Irritant diaper dermatitis
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Seborrheic dermatitis
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Atopic dermatitis
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Psoriasis
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Psoriasiform diaper dermatitis with id reaction
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Erosive perianal eruption
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Pseudoverrucous papules
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Granuloma gluteale infantum
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Senna-induced blistering after laxative ingestion
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Allergic contact dermatitis due to diaper components
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Diaper dye dermatitis and ‘Lucky Luke’ dermatitis
Infections
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Candidiasis
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Bullous impetigo/staphylococcal scalded skin syndrome
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Perianal streptococcal dermatitis/streptococcal intertrigo
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Pseudomonas /ecthyma gangrenosum
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Tinea infection
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Herpes simplex infection
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HPV infection (condylomata)
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Molluscum contagiosum
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Coxsackie viral infection (hand, foot, and ‘butt’ exanthem)
Metabolic
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Nutritional abnormalities
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Zinc deficiency
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Acrodermatitis enteropathica
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Acrodermatitis enteropathica-like eruptions
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Methylmalonic acidemia
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Propionic acidemia
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Glutaric aciduria (type 1)
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Maple syrup urine disease
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Ornithine transcarbamylase deficiency
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Citrullinemia
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Biotin deficiency
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Holocarboxylase deficiency
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Cystic fibrosis
Miscellaneous
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Langerhans’ cell histiocytosis
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Kawasaki disease
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Granular parakeratosis
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Pyramidal perianal protrusion
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Nascent hemangioma
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Lichen sclerosus
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Pyoderma gangrenosum
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Chronic bullous disease of childhood
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Bullous pemphigoid
| Disease | Usual age | Skin: morphology | Skin: usual distribution | Clinical: other | Method of diagnosis/findings |
|---|---|---|---|---|---|
| Irritant diaper dermatitis | Between 3 weeks and 2 years. Peak ages 9–12 months | Erythema, with fine scaling and glazed skin surface. Erosions and ulcerations when severe | Convex surfaces of upper inner thigh, lower abdomen and buttock; spares intertriginous creases | Risk factors: cloth diapers, diarrhea | Clinical |
| Erosive perianal eruption | Usually infants 6 weeks to 3 months of age | Well-demarcated erosions and superficial ulcerations, 0.5–1.5 cm | Perianal skin, opposing areas of buttocks | Associated with frequent stooling of any etiology | Clinical |
| Pseudoverrucous papules | Usually infants rather than newborns | Well demarcated dome-shaped papules 2–10 mm, with shiny, smooth red or white surface | Perianal region, buttocks, vulvar, scrotal, or around enterostomal openings | Severe, intractable diarrhea from any cause; short gut syndrome, following surgery for imperforate anus or pull through for Hirschsprung disease. May mimic condylomata clinically | Usually clinical Biopsy shows reactive acanthosis or psoriasiform spongiotic dermatitis |
| Granuloma gluteale infantum | Usually infants rather than newborns | Oval red-brown to violaceous dermal papules or nodules 5 mm to 2–3 cm. Lesions run parallel to skin lines | Perianal, perivulvar or gluteal surfaces of the diaper region. Rarely inguinal folds, neck and axillae | Usually a history of chronic diaper eruption treated with multiple products, including fluorinated steroids | Clinical Biopsy shows dense superficial and deep inflammatory infiltrate composed of lymphocytes, histiocytes and plasma cells, proliferation of dermal blood vessels and extravasated red blood cells and hemosiderin |
| Granular parakeratosis | Usually 9–22 months of age | Asymptomatic, geometric, yellow brown, scaling plaques with underlying erythema | Areas of friction and pressure in diaper region. May involve axillae | None | Clinical Biopsy shows abnormal keratinization and retention hyperkeratosis |
| Infantile seborrheic dermatitis | First 4–6 weeks of life, but any time in the first year | Erythematous, well-demarcated patches involving the creases; may affect entire diaper region. Scale often minimal in diaper region | Multiple areas may be involved, especially scalp, eyebrows, sides of nose, axillae, chest, and diaper region | Generally happy babies, unlike infants with AD, who have more pruritus | Clinical KOH to rule out associated candidiasis |
| Psoriasis | Under 2 years | Brightly erythematous, well-demarcated patches and plaques typically with absent or thin white scale | Often starts on convex surfaces, may affect entire diaper region including creases, gluteal cleft; may also involve face, scalp, trunk, and umbilicus | Eruption often asymptomatic and unresponsive to usual diaper dermatitis treatments | Clinical ± Skin biopsy shows epidermal acanthosis, parakeratosis dilated capillaries |
| Candidal diaper dermatitis with psoriasiform id reaction | Usually infants 6–24 months but may occur earlier | Initial candidal diaper rash with erythematous patches and peripheral satellite papules or pustules with associated papules and scaly plaques elsewhere on the body | Typical (usually severe) eruption in the diaper area followed by rapid onset of papules and plaques involving the torso, face, less prominent on extremities | Usually asymptomatic; occasionally pruritic | Clinical KOH+ pseudohyphae and spores in diaper region early on |
| Allergic contact dermatitis | Usually after 6 months of age | Erythema and small vesicles leading to area of eczematous eruption of red papules and vesicles overlying areas of edema | Depends on contact allergen involved: diaper dye dermatitis at margins of diaper Entire diaper region if due to applied topical products | Associated pruritus | Clinical Biopsy shows spongiotic dermatitis with eosinophils |
| Senna-induced blistering | Usually less than 5 years | Diamond-shaped erosions/ulcerations along the buttocks, linear borders aligning with the diaper edge | Sparing of the perianal area and gluteal cleft | History of ingestion of senna-containing laxatives (e.g., Ex-Lax ® ) 24 h before lesions appeared May be misdiagnosed as child abuse | Clinical History of diarrhea, recent senna ingestion in infant or child |
| Disease | Usual age | Skin: morphology | Skin: usual distribution | Clinical: other | Method of diagnosis/findings |
|---|---|---|---|---|---|
| Candidiasis | Common after 2 months of age | Beefy-red eruption emanating from folds with satellite pustules or erythematous eruption extending over perineum with peripheral scale | Begins in inguinal folds, may involve entire perineum | Often history of preceding antibiotic use or diarrhea preceding eruption May have associated oral thrush | Clinical KOH and culture positive for Candida |
| Impetigo | Often in first few weeks of life | Single or multiple flaccid bullae or moist superficial erosions | Often starts in umbilical stump; spreads to intertriginous areas of diaper region | Usually no other symptoms but neonates with hematogenous spread may develop septicemia, osteomyelitis or septic arthritis | Clinical Gram stain, culture Biopsy rarely required but shows subcorneal pustule |
| Perianal/perineal bacterial dermatitis | Usually after 6 months of age, more common in toddlers | Moist, bright red erythema around perianal skin with yellowish sticky exudates at periphery. May have small pustules in surrounding skin | Perianal skin most common but can be in inguinal creases, other body folds | Local pain and tenderness common, fever rare. May have concomitant streptococcal pharyngitis. May be trigger for guttate psoriasis | Clinical Culture positive for Staphylococcus aureus or Β-Hemolytic Streptococcus spp. |
| Ecthyma gangrenosum | Usually seen in very premature or immuno-compromised infants | Erythematous macule that rapidly evolves into grey nodule, necrotic bulla or ulceration with surrounding bright red areola | May occur anywhere but 50% occur in perineal/gluteal area | Associated neutropenia common May rarely occur in diaper region in normal infants | Clinical Gram stain and culture of lesions or +blood culture |
| Tinea corporis in diaper area | Usually seen in toddlers | Erythematous scaling papules and plaques with border in diaper region. Deeper follicular papules and pustules in chronic cases | Buttocks, thighs and lower abdomen but may involve entire diaper area | Often family history of tinea pedis or other tinea infection | Clinical KOH and culture+ for dermatophyte, usually T. rubrum or T. mentagrophytes |
| Herpes simplex | Presents 2–8 days after contact with infected individual | Grouped 2–3 mm umbilicated vesicles and erosions on erythematous base | Neonatal HSV may present on buttocks after breech delivery | Fever and regional adenopathy | Clinical +HSV culture or DFA or PCR. +Tzanck smear of base of vesicle |
| Condylomata acuminata | Usually seen through vertical transmission from an infected mother; incidence in young infants from child abuse unknown but low | 1–3 mm flesh-colored papules that may coalesce to form plaques. Verrucous to velvety surface | May occur on any part of the perineum | Usually asymptomatic | Clinical HPV serotyping available |
| Molluscum contagiosum | Rare in neonates, increasingly common in toddlers and early childhood | Umbilicated flesh-colored or pink papules, usually several, occasionally large numbers | Often in folds or areas of friction | May have associated molluscum dermatitis | Clinical or biopsy if diagnostic uncertainty |
| Coxsackie viral infection | 1–4 years of age | Small red macules that rapidly evolve into superficial ovoid vesicles on hands and feet. Small papules and superficial erosions seen over buttocks and thighs | Hand, foot, and ‘butt’ (diaper area) exanthem with erosions and vesicles of buccal area, tongue, gingiva and anterior tonsillar pillars | Fever and malaise Rarely, encephalitis, aseptic meningitis, myocarditis Enterovirus 71 causes pulmonary hemorrhage | Clinical Viral culture or PCR CVA6 prevalent in recent outbreaks often with confluent diaper involvement |
| Disease | Usual age | Skin: morphology | Skin: usual distribution | Clinical: other | Method of diagnosis/findings |
|---|---|---|---|---|---|
| Zinc deficiency/ acrodermatitis enteropathica (AE) | True genetic AE occurs within 3 months after weaning; Zn deficiency common in breast-fed premature infants within 1–2 months of age | Crusted, scaling, eczematous to psoriasiform dermatitis. Face and diaper area | Periorificial, perineum, acral and periungual areas | Irritability, diarrhea, sparse hair, recurrent candidal infections especially paronychia, failure to thrive | Clinical Low serum zinc Low alkaline phosphatase |
| Cystic fibrosis | Infancy | Periorificial and truncal dermatitis | Similar to AE | Significant edema, diarrhea, irritability, alopecia, failure to thrive | Clinical Sweat chloride test CFTR mutational analysis |
| Langerhans’ cell histiocytosis | Birth–4 years | Single, few or multiple lesions. Morphology may vary: yellow-brown papules, nodules, vesicles, erosions, ulcerations, atrophy, palpable petechial lesions, purpura, scale or crusting either alone or in combination | Folds of diaper region characteristic, also trunk, scalp and retroauricular regions | Gums, teeth and nails may be involved Bony involvement in 50%; lymphadenopathy 14%; liver or CNS in 10% (diabetes insipidus) | Clinical Confirm with skin biopsy showing infiltrate of CD1A+ cells in epidermis and dermis |
| Pyramidal perianal protrusion | Usually 1–30 months of age | Pyramidal shaped soft tissue ‘tag-like’ protrusion – occasionally has a tongue-like lip | Seen in midline of perineum typically anterior to the anus but can be at other locations. | Often a history of constipation or diarrhea. May be associated with lichen sclerosus (LS) | Clinical Biopsy shows normal skin unless LS changes present (rarely required) |
| Nascent ulcerated infantile hemangioma | Birth to a few days of life | Oval to annular area of superficial to full thickness skin ulceration. Often surrounding telangiectasia or tiny vascular papules | Perianal, perivulvar and buttocks, may occur on lip or perioral region | Associated pain, occasionally secondary infection. Concern for spinal dysraphism/urogenital anomalies with very large lumbosacral lesions | Clinical Hemangioma becomes evident over next few days to weeks. Biopsy: Glut-1 + vessels |
| Lichen sclerosus | Usually in childhood 5–7 years, but may be seen in infancy | White, glistening, atrophic changes in the vulvar area and perianal skin. Associated purpura, and small hemorrhagic vesicles may be seen | Figure-of-eight distribution in perineum. Phimosis in boys; rarely extragenital lesions | Associated pain, itching, dysuria constipation and encopresis may be present | Clinical Biopsy confirms (rarely necessary) |
| Pyoderma gangrenosum | Uncommon in infancy but reported as young as 3 months | Tender papulopustule rapidly evolves into undermined ulcer with violaceous border. Rarely bullous and hemorrhagic | Head and anogenital sites most common in infants and children. Lower extremities in older children | Painful, usually associated with IBD, also seen in immunodeficiency, leukocyte adhesion defect, leukemia, rheumatic disorders | Clinical Biopsy not specific but helpful to exclude other disorders, i.e., infectious ulcers and vasculitis |
| Chronic bullous disease of childhood | Usually in early childhood. Rare in infancy | Annular to polycyclic vesicles and bullae forming rosettes or ‘string of pearls’ | Diaper area, buttocks and inner thighs characteristic with spread to the trunk and scalp and face | May present initially with fever or other constitutional symptoms | Clinical Confirm with biopsy: subepidermal blister with polys and eosinophils Immunofluorescence +linear IgA deposits |
| Bullous pemphigoid | Rare in infants and children but earliest reported case 2 months of age | Urticarial papules and plaques evolve into tense, often hemorrhagic bullae 0.25–2 cm in size. Blisters on normal or inflamed skin | Widespread distribution, often involves perineum, flexures of limbs and face; mucosal involvement may occur in older children | Associated itching and pain | Clinical Confirm with biopsy, subepidermal blister with eosinophils Immunofluorescence, deposits of C 3, and IgG at BMZ |
| Kawasaki disease | Infancy to 5 years | Eruption may be polymorphous; often involves diaper region in young infants, with perineal erythema, small sterile pustules, urticarial lesions, early evidence of desquamation in perineal area | Accentuation in perineal area but can be widespread macular erythema, urticarial, scarlatiniform, or maculopapular lesions | Persistent fever, irritability, conjunctivitis, strawberry tongue, fissured lips, cervical adenopathy, peripheral edema, leukocytosis, thrombocytosis, increased ESR, sterile pyuria, pericardial effusions and myocarditis | Diagnostic clinical criteria Echocardiogram |
| Clear cell papulosis | Infants to toddlers | Small hypopigmented macules, flat-topped papules | Diaper area, abdomen, milk line | Can be familial or sporadic | Biopsy shows large clear cells within the lower epidermis, PAS+ |
The term ‘diaper rash’ refers to any eruption in the area covered by the diaper. There are eruptions that are directly related to the wearing of diapers; those aggravated by wearing diapers; and those that occur in the diaper region, irrespective of whether diapers are worn or not. The majority of severe eruptions which have been a direct consequence of diapering, are more uncommon in countries where disposable diapers are used. Ethnic and cultural differences related to the practice of diapering newborn infants have evolved over hundreds of years, from swaddling in the middle ages to the high-technology, multilayered disposable diapers of the twenty-first century. These latter practices have led to a marked reduction in the frequency of diaper eruptions, particularly irritant diaper dermatitis (IDD).
Care of the diaper area in the newborn
The diaper area in newborns is exposed to urine and feces and it is a combination of both that causes IDD. Normal care of the perineal area should be aimed at gentle removal of the excreta, frequent change of diapers, and use of a mild emollient (petrolatum) to prevent irritation. Infants should be bathed with a mild soap. In preterm infants or those with a tendency to develop irritant diaper dermatitis, a barrier product should be applied to the diaper area with each diaper change. A study integrating these practices into skin care routines for infants in a neonatal intensive care unit has led to significant improvements, with less dryness, redness, and skin surface damage. Feces should be removed from the skin as soon as possible after soiling. Plain water alone or a very mild soap, with gentle use of a moist cotton washcloth, is sufficient to remove the feces and urine before the area is gently dried. Rubbing should be avoided. Fragrance- and alcohol-free baby wipes are another convenient option. Baby wipes are now universally alcohol free and contain 98% water.
The ideal or perfect barrier product has yet to be formulated. Traditionally, both lipophilic and hydrophilic ointments and pastes have been used, often combined with zinc oxide. The more lipophilic products may be highly occlusive, whereas the hydrophilic products are more hydrating but function less effectively as a barrier. Pastes such as zinc oxide paste USP (25% zinc oxide, 25% corn starch, 50% petrolatum) are a more effective barrier, but are more adherent and difficult to remove – caregivers may inadvertently irritate the infant’s skin when trying to remove the residual feces and barrier cream. In general, water-in-oil formulations with a lipid content of 50% provide a better barrier than lighter oil-in-water products. Plain petrolatum is recommended for routine use. Soft zinc paste products such as Ihle’s Paste® (Rougier Pharma Canada) or Triple Paste® (Summers Labs, Collegeville, PA) contain a combination of ingredients such as zinc oxide, cornstarch, petrolatum and lanolin, and are excellent, affordable, nonsensitizing products for both prevention and treatment of IDD. Chapter 5 discusses many of the common ingredients in commercial diaper rash products. Talcum or baby powders and products containing boric acid should not be used because of inherent or potential toxicities associated with their use.
Diaper-related eruptions
Irritant diaper dermatitis
Jacquet gave the first description of diaper dermatitis in 1905. Irritant diaper dermatitis (IDD) does not usually develop during the neonatal period, particularly in the first 3 weeks of life, and eruptions in the diaper area in this age group should be assumed to be due to causes other than irritation until proven otherwise. Onset of IDD is generally between 3 weeks and 2 years of age, with prevalence highest between 9 and 12 months. The condition was previously common, affecting 25% of children seen in a clinic for dermatological diseases, but the incidence has decreased remarkably in Western cultures owing to the advent of disposable diapers. In certain societies, such as China, where diapering has not been a social convention, IDD has been distinctly uncommon until recently, with the adoption of Western diapering practices.
Home laundering of diapers is now uncommon in Western societies: most parents in developed countries diaper their infants with disposable or cloth diapers from a diaper service. Modern superabsorbent disposable diapers have been shown to be more effective than washable cloth diapers in reducing IDD, yet it is estimated that 1–2% of the non-biodegradable waste in North American landfills is composed of disposable diapers.
The evolution of disposable diapers from paper to absorbent cellulose centers, to present-day disposables, which contain both an intricate wicking system that prevents backflow and an absorbent gel matrix that can hold 80 times its weight of fluid, has reduced the prevalence of IDD. The most recent advances in disposable diapers include a slow-release petrolatum surface and a breathable outer sheet.
The most important factor in preventing IDD is the frequency and number of diaper changes. Other factors causing IDD include episodes of diarrhea, antibiotic use, and anatomical problems such as short bowel syndrome. Whereas cloth diapers are less efficient at reducing skin wetness, friction and pH, there is a risk that the expense of superabsorbable diapers may prevent parents from changing the diaper sufficiently often, thus contributing to the development of IDD.
Cutaneous findings
IDD presents as erythema on the convex surfaces of the inner upper thigh, the lower abdomen, and buttock areas, the areas most in contact with the diaper. The creases and the suprapubic area in boys are spared ( Fig. 17.1 ). The eruption may become more severe and inflammatory, with yeast colonization, and enlarging areas of involvement, including the creases. In more severe cases, the erythema may be accompanied by a glistening or glazed appearance and a wrinkled surface.
Jacquet’s erosive dermatitis presents with well-demarcated punched-out ulcers and erosions ( Fig. 17.2A , B 
). It is seen less commonly with the use of disposable diapers, and has usually been associated with infrequent diaper changes and poor removal of chemicals used in home laundering. It may also be seen in infants who have short bowel syndrome or following surgery for Hirschsprung disease, which may result in chronic diarrhea.
Etiology and pathogenesis
At birth, a newborn’s skin undergoes a sudden transition accompanied by drying and cooling of the skin surface as it adapts to its new environment. Visscher has measured the changes in the newborn’s epidermal barrier properties over the first 4 weeks of life, showing increased surface hydration, less transepidermal water movement under occlusion, and a decrease in surface pH. Diapered and non-diapered sites are indistinguishable at birth, but over the first 2 weeks of life diapered areas show consistently increased pH and hydration, thus setting the stage for IDD.
IDD results from the interaction of several factors associated with prolonged contact of the skin with a combination of both urine and feces ( Tables 17.1–17.3 ). The wearing of diapers causes a significant increase in skin wetness and pH. Prolonged wetness leads to maceration of the stratum corneum due to disruption of the intercellular lipid lamellae.
Weakening of the stratum corneum from excess hydration makes the skin more susceptible to damage by friction from the diaper. Fecal lipases and proteases are activated by the increased pH in the urine. In addition, the acidic pH of the skin surface is essential for maintaining a normal cutaneous microflora, which protects against invasion by pathogenic bacteria and yeasts. When diarrhea occurs, the fecal lipases and proteases increase in the diaper, leading to further damage to the stratum corneum. In the etiology of primary IDD, ammonia and Candida play less of a role than previously thought.
Differential diagnosis
Ordinarily the diagnosis is straightforward and uncomplicated. Many of the disorders listed in Box 17.1 present with subtle differences from IDD, particularly psoriasis and allergic contact dermatitis. Atopic dermatitis (AD) classically spares the diaper region, but infants with widespread AD may have involvement of the skin just above the margin of the diaper. Strict attention to the morphology and location of lesions, the absence of pustules or vesicles, and the absence of lesions in the creases should lead the physician to the correct diagnosis.
Treatment and care
Evidence-based practice guidelines for care of diaper dermatitis in hospitalized patients has reduced prevalence in high risk units.
Mild topical steroid therapy (1% hydrocortisone ointment) covered by a barrier product three times daily, will clear the majority of IDD that does not respond to barrier products alone. The use of potent fluorinated topical steroids in the diaper region is not recommended as the natural occlusion of this area will promote increased absorption and may cause atrophy, striae, and adrenal suppression. When the practitioner is faced with a severely inflamed recalcitrant dermatitis in the diaper area, it is safe to use a week-long course of a medium-potency topical steroid to bring the eruption under control. The role of topical immunomodulators in the management of diaper dermatitis is unclear and cannot be recommended until further data are available on their safety and use in infants under 2 years of age.
Erosive perianal eruption
This entity presents with erosions and ulcers in the perianal skin and occurs most commonly between 6 weeks and 3 months of age, but can be seen at other ages. The etiology is almost universally associated with frequent stooling, either in breast-fed babies, children with diarrhea due to malabsorption, or infection in infants with short gut syndrome ( Fig. 17.3A , B 
). This condition may eventuate into pseudoverrucous perianal papules in infants who undergo enterostomal closure, or following pull-through surgery for Hirschsprung disease. In mild cases, frequent diaper changes and use of a barrier product such as zinc oxide or triple paste with a low- to medium-strength topical steroid ointment applied two to three times daily, is helpful. In patients with short gut or other malabsorption syndromes the condition may be chronic, unremitting, and very difficult to treat. Incorporation of potato-derived protease inhibitor into a diaper barrier product has improved control of dermatitis in a small cohort of patients following colon resection for long-segment Hirschsprung disease.
Pseudoverrucous papules
Pseudoverrucous papules (PVP; sometimes referred to as ‘pseudoverrucous papules and nodules’), and granuloma gluteale infantum, the more severe forms of Jacquet’s erosive diaper dermatitis, are probably best viewed as reaction patterns following chronic, unremitting irritation due to feces, urine, or a combination thereof. Pseudoverrucous papules were first described by Goldberg and colleagues in the setting of chronic diaper dermatitis, encopresis or peristomal skin irritation.
Well-documented precipitating factors leading to this condition include chronic diarrhea due to malabsorption, short-gut syndrome, or surgical repair of Hirschsprung disease or imperforate anus; leakage around stomas (either urinary or fecal); and chronic incontinence. Clinical features include dome-shaped papules, typically varying in size from 2 to 10 mm, often with a shiny, smooth, white or red surface ( Fig. 17.4 ). Biopsy specimens reveal reactive acanthosis or psoriasiform spongiotic dermatitis. The lesions regress when the irritating factor is removed. Recognition of this entity is important because pseudoverrucous papules and nodules may mimic other dermatoses, especially condyloma acuminatum, and unnecessary work-up for sexual abuse may be initiated.
Granuloma gluteale infantum
Granuloma gluteale infantum (GGI) was originally described by Tappeiner and Pfleger. It is rarely seen today and there are only 30 cases reported in the literature. Infants present with oval red-brown-purple dermal nodules on the gluteal surface and diaper area ( Fig. 17.5 ). Rarely, lesions may be present in the intertriginous areas, including the neck and axilla. The long axis of the lesions runs parallel to skin lines. In the majority of affected infants there is a history of a preceding eruption in the diaper region treated with fluorinated topical steroids. Similar granulomas in the diaper region have been noted in adults who are incontinent or confined to bed. The etiology of GGI is unclear, but some have hypothesized that it is a skin response to the combined effects of inflammation, maceration, local infection with Candida , and use of fluorinated steroids. The sparing of deep folds suggests that occlusion by the diaper is necessary for its formation.
As for all forms of irritant diaper dermatitis, treatment should be directed at correcting the underlying cause of the chronic urine or fecal leakage whenever possible, as well as frequent use of a barrier product. Lesions generally resolve completely and spontaneously after a period of several months if the source of chronic irritation can be removed.
Senna laxative-induced blistering dermatitis in toddlers
Phenolphthalein was removed from all over-the-counter laxatives in 1999 and replaced with senna, an ornamental plant-derivative containing multiple anthraquinones. In a review of data from six poison centers in 2002, of 111 children less than 5 years of age who accidentally ingested senna-containing laxatives, 33% experienced severe diaper rash. The eruption is seen in infants or toddlers wearing diapers or pull-ups after overnight contact of the skin with large loose stools following accidental ingestion of chocolate squares of senna-containing laxatives. Therapeutic use of senna in a 3-year-old child with Hirschsprung disease and a pull-through procedure produced a similar eruption. This severe irritant contact dermatitis presents with distinct features, including a diamond-shaped lesion along the buttocks, linear borders aligning with the diaper edge, with usual sparing of the perianal area and gluteal cleft. Patients with this entity may be initially misdiagnosed with abusive scald burns ( Fig. 17.6 ).
Granular parakeratosis
Granular parakeratosis is a rare disorder of keratinization characterized by retention hyperkeratosis. Its precise etiology is unknown, but it is generally viewed as a reaction to chronic irritation or possibly as a reaction to certain topical products such as zinc oxide, which are commonly used in the diaper area. It was originally described in the axillary region of adults, but there have recently been several reports in infants 9–22 months of age.
Infants usually present with asymptomatic, geometric yellow-brown, superficial scaling plaques with pronounced underlying erythema in areas of friction and pressure in the diaper region. A second pattern of linear warty papules in the inguinal area has also been described ( Fig. 17.7 ).
The cause of this peculiar entity is obscure, but immunohistochemical and electron microscopic studies suggest that there is a defect in the processing of profilaggrin to filaggrin, which results in failure of the normal degradation of keratohyalin and clumping of keratohyalin filaments during cornification. These abnormal components result in the retention hyperkeratosis seen. Friction, moisture, and occlusion from diapers may trigger defective maturation of the stratum corneum at local sites in susceptible infants.
Treatment is empiric, with variable response to topical steroids, calcineurin inhibitors, calcipotriene cream, keratolytics, and emollients. The majority of cases clear spontaneously after months, but occasionally patients may have lesions for several years.
Infantile seborrheic dermatitis (ISD)
First described by Unna in 1887, ISD (see also Chapter 15 ) is a disease that affects infants usually in the first 2 years, with a distinct inflammatory eruption that primarily involves the scalp, retroauricular area, face, chest, diaper, and intertriginous areas. A precise definition is lacking; some physicians confine the entity to the presence of scalp scaling without inflammation called ‘cradle cap’ that affects the vertex of the scalp, whereas others only use the term if there is inflammation of the scalp and in other seborrheic sites.
Cutaneous features
The eruption usually begins under 6 weeks of age, but may occur up to 1 year or even later. Both sexes are equally affected. The vast majority of infants develop cradle cap alone; this is a collection of asymptomatic, greasy keratin on the vertex of the scalp (retention hyperkeratosis), without inflammation or involvement of other areas. A few patients develop multiple areas of involvement, including erythematous well-demarcated patches in the retroauricular area, eyebrows, along the sides of the nose, and involving the axillae, chest, and diaper area. The most commonly involved areas are the scalp and diaper area ( Fig. 17.8 ). Although there is often a yellow, greasy scale on the erythema, this is not invariably present and is usually absent in the diaper area, where lesions consist of erythematous, well-demarcated patches involving the creases, but sometimes affecting the whole region. Scale is unusual or minimal in the diaper area. If there is invasion by Candida albicans , crusting and scaling may occur.
