Chapter 111. Diaper Rash and Perianal Dermatitis

A 2-month-old baby girl was brought to the office with a severe diaper rash that was not getting better with Desitin. Upon examination, the physician noted a white coating on the tongue and buccal mucosa. The diaper area was red with skin erosions and satellite lesions (Figure 111-1). The whole picture is consistent with candidiasis of the mouth (thrush) and the diaper region. The child was treated with oral nystatin suspension and topical clotrimazole cream in the diaper area with good results.

Diaper rash is a general term used to describe any type of red or inflammatory skin rash that is located in the diaper area.

Diaper dermatitis, napkin dermatitis.

• Diaper dermatitis is the most common dermatitis of infancy.
• Variability in prevalence of 4% to 35% among children in their first 2 years of life in different studies.1
• Diaper rash is thought to be present in 25% of children presenting for outpatient visits.2
• No differences in prevalence between genders or among ethnic groups.
• One study showed an incidence of 19.4% in children ages 3 to 6 months.1
• Higher incidence among formula-fed compared with breastfed infants.1
• Condition typically begins around age 3 weeks, peaks at age 9 to 12 months, and then decreases with age until it resolves completely with toilet training.
• Individual episodes last from 1 day to 2 weeks.
• Aggravating factors include poor skin care, diarrhea, recent antibiotic use, and urinary tract abnormalities.
• Perianal streptococcal dermatitis occurs in children between 6 months and 10 years of age (Figures 111-2 and 111-3).

• Primary diaper dermatitis—An acute skin inflammation in the diaper area with a multifactorial etiology.3 The main cause is irritation of thin skin as a result of prolonged contact with moisture including feces and urine. The multiple factors involved are:

  1. Occlusion/lack of exposure to air.

  2. Friction and mechanical trauma.

  3. Local irritants—Fecal proteases and lipases.

  4. Increased pH.

  5. Maceration of the stratum corneum with loss of the protective barrier function of skin.

• Irritant diaper dermatitis (IDD) is a combination of intertrigo (wet skin damaged from chafing) and miliaria (heat rash) when eccrine glands become obstructed from excessive hydration. It is a noninfectious, nonallergic, often asymptomatic contact dermatitis that typically lasts for less than 3 days after a change in diaper practices.
• Candidal diaper dermatitis—Within 3 days, 45% to 75% of diaper rashes are colonized with Candida albicans of fecal origin.
• Bacterial diaper dermatitis may be a secondary infection caused by Staphylococcus aureus or Streptococcus pyogenes. Other common bacterial isolates include Escherichia coli, Peptostreptococcus, and Bacteroides. Usually occurs during the warm summer months.
• Perianal streptococcal dermatitis is caused by group A β-hemolytic streptococci (Figures 111-2 and 111-3).

• Diarrhea.
• Formula-fed infants.
• Recent antibiotic use.
• Urinary tract abnormalities.
• Poor skin care.

Clinical Features

• IDD begins with shiny erythema with or without scale and poorly demarcated margins on the convex skin surfaces in areas covered by diapers. Moderate cases can have papules, plaques, vesicles, and small superficial erosions that can progress to well-demarcated ulcerated nodules typically with sparing of skin folds (Figure 111-4).
• Pustules or papules beyond the rash border (called “satellite lesions”), involvement of the skin folds, and white scaling all indicate a fungal infection with Candida (Figure 111-5).
• Secondary bacterial infections can have redness, honey-colored crusting, swelling, red streaking, and/or purulent discharge. With impetigo in the diaper area, bullae are not usually intact but instead present as superficial erosions.
• Perianal streptococcal dermatitis is a bright red, sharply demarcated rash sometimes associated with blood-streaked stools (Figure 111-2).

Typical Distribution

Diaper dermatitis is primarily found on the buttocks, the genitalia, the mons pubis and lower abdomen, and the medial thighs. Be sure to evaluate for rashes outside of the diaper area as well. If Candida is suspected, the oropharynx should be inspected for signs of thrush, such as adherent white plaques on the mucosa.

Laboratory Studies

Clinical diagnosis is based primarily on the physical examination. Rarely indicated tests that are occasionally used in more complicated cases include potassium hydroxide preparation for fungal elements, mineral oil preparation for scabies, complete blood count with differential, zinc level, or skin biopsy (Figure 111-6). A rapid strep test can be used to diagnose perianal streptococcal dermatitis (Figures 111-2 and 111-3).

There are two distinctive severe variants of IDD. Jacquet's diaper dermatitis (dermatitis syphiloides posterosiva or erosive variant) is a term used to describe severe, slow-healing, noduloerosive lesions with heaped-up borders seen in children with persistent diarrhea.4 Granuloma gluteale infantum is a rare and poorly understood primary diaper dermatitis that presents with granulomatous nodules that can have large, raised, purple erosions with rolled margins. It resolves spontaneously over the course of a few months once the causative agent is discovered and removed, often with residual scarring and hyperpigmentation.5

Perianal pseudoverrucous papules are shiny, smooth, red, moist, flat-topped lesions that are commonly confused with the genital warts that occur in the context of Hirschsprung disease.

Secondary diaper dermatitis is an eruption in the diaper area with a defined etiology. Atopic dermatitis, seborrheic dermatitis, and psoriasis are examples of rashes that can appear anywhere on the body and can be exaggerated in the groin as a result of wearing diapers. Family history of atopy or psoriasis and rash in other locations besides the groin can be helpful.

Congenital syphilis, scabies, HIV, Langerhans cell histiocytosis, and acrodermatitis enteropathica are examples of rashes in the diaper area unrelated to the diaper. Allergic contact dermatitis as a result of an allergen in the diaper itself is possible but rare.

Suspect acrodermatitis enteropathica caused by zinc deficiency when the diaper dermatitis is severe and accompanied by perioral dermatitis (Figure 111-6). The serum zinc level will be low and zinc supplementation will be needed.

Treatment

• Parental behavior change to keep the skin as exposed and dry as possible. SOR B Frequent diaper changes (as soon as they are wet or soiled and at least every 3 to 4 hours); use disposable diapers. SOR B Frequent gentle cleaning of the affected area with lukewarm tap water instead of commercial wipes containing alcohol and pat dry. A squeeze bottle with lukewarm water can be used to avoid rubbing the delicate skin.
• Superabsorbent diapers that pull moisture away from the skin are helpful.1 SOR B
• Apply barrier preparations, including zinc oxide paste, petroleum jelly, Vitamin A & D ointment, or Burow solution, to affected area after each diaper change.1 SOR B Pastes are better than ointments, which, in turn, are better than creams or lotions. Avoid products with fragrances or preservatives to minimize allergic potential. Apply thickly like “icing on a cake.” These barrier preparations should be used on top of other indicated therapies.
• For moderate to severe inflammation, consider a nonfluorinated, low-potency topical steroid such as 1% hydrocortisone ointment (up to 3 times daily) to the affected area until the dermatitis is gone. To avoid skin erosions, atrophy, and striae, it is best to not go beyond 2 weeks of therapy with any topical steroid on a baby's bottom.
• For Candida, use topical nonprescription antifungal creams such as clotrimazole, miconazole after every diaper change until the rash resolves. SOR B For concomitant oral thrush, treat with oral nystatin swish and swallow 4 times daily.
• Avoid combination antifungal-steroid agents that contain steroids stronger than hydrocortisone (e.g., Lotrisone). Potent topical steroids can cause striae and skin erosions, hypothalamus-pituitary-adrenal axis suppression, and Cushing syndrome.1
• For mild bacterial infections, use topical antibiotic ointments such as bacitracin or mupirocin after every diaper change until the rash resolves. SOR B
• For more severe bacterial infections, consider a broad-spectrum oral antibiotic such as amoxicillin-clavulanate. Perianal bacterial dermatitis has been reported to be predominantly caused by S. aureus.6 Oral cephalexin is a good choice because it covers S. aureus and group A β-hemolytic streptococcus. If methicillin- resistant S. aureus (MRSA) is suspected, consider trimethoprim- sulfamethoxazole. SOR B
• Ciclopirox 0.77% topical suspension (Loprox), a broad-spectrum agent with antifungal, antibacterial, and antiinflammatory properties, was used safely and effectively in 1 trial of 44 children to treat diaper dermatitis caused by Candida.1 SOR B
• Recommend dye-free diapers for allergic contact dermatitis. SOR B

• Keep the diaper region as dry and clean as possible.
• Promote the use of barrier preparations daily to maintain skin integrity.
• There is no evidence to suggest that topical vitamin A prevents diaper dermatitis.7 SOR B
• Disposable diapers—Although many individual trials show benefits, a 2006 Cochrane Review found that there is not enough evidence from good quality, randomized, controlled trials to support or refute the use and type of disposable diapers for the prevention of diaper dermatitis in infants.8 SOR B

Diaper dermatitis has an excellent prognosis when treated as above.

No follow-up needed unless the rash worsens or persists. The exception is severe bacterial infection where follow-up is recommended because recurrences are common.

Prevention and early treatment are the best strategies. Keep the child's diaper area as clean, cool, and dry as possible with frequent diaper changes. Do not use creams that contain boric acid, camphor, phenol, methyl salicylate, compound of benzoin, or talcum powder or cornstarch. Reassure parents that, although this common condition is sometimes distressing for parents and uncomfortable for children, it is rarely dangerous.

Patient Resources

• FamilyDoctor.org. Diaper Rash—http://familydoctor.org/familydoctor/en/diseases-conditions/diaper-rash.html.
• WebMD. Diaper Rash-Topic Overview—http://children.webmd.com/tc/diaper-rash-topic-overview.

Provider Resources

• Medscape. Diaper Rash—http://emedicine.medscape.com/article/801222.