Diaper dermatitis, also called diaper rash, encompasses several different dermatoses that can occur on the skin underneath the diaper in infants.

Primary irritant diaper dermatitis, the most common form of diaper rash, and its management is presented below; other causes of diaper rash are presented in Table 2.1.

Diaper dermatitis is the result of overhydration of the skin due to urine and sweat produced by the occlusive diaper that leads to increased permeability of the skin to irritants.

Irritant triggers include friction, or rubbing of skin on skin, soaps, antibacterial and cleansing substances found in baby wipes and topical diaper ointments, urine, and proteolytic enzymes in stool.

Urine increases the skin's pH which intensifies the activities of fecal proteases and lipases.

When friction is the primary cause of the dermatitis, the term “chafing dermatitis” or “frictional dermatitis” is used.

Irritant diaper dermatitis may also be exaggerated by the presence of atopic dermatitis, seborrheic dermatitis, or a secondary infection by Candida albicans.

Diaper dermatitis presents as erythematous, shiny, moist patches on the convex surfaces of the buttocks, the vulva, perineal area, proximal thighs, and lower abdomen.

Eczematous plaques on the labia appear shiny and wrinkly (Fig. 2.17).

Lesions typically spare the body folds (intertriginous creases) because such areas do not come into direct contact with the diaper.

With neglect, erosions or ulcerations may develop.

The diagnosis is made clinically.

When irritant diaper dermatitis is not improving with adequate treatment, it is important to consider other less common causes of diaper dermatitis. The clinical features, diagnosis, and treatment of these are presented in Table 2.1.

The most common form of diaper rash is a primary irritant contact dermatitis, a type of eczematous dermatitis triggered by urine, feces, moisture, and occlusion (also discussed in Chapter 4: Eczema in Infants and Children).

It can first present as early as the first few weeks of life, has a peak incidence at 9 to 12 months, but can occur any time when diapers are worn.

Avoid wipes when an eczematous eruption is present as the skin barrier is compromised.

Wash the affected area with a nonsoap cleanser (Cetaphil cleanser) or gentle soap and a soft, moistened paper towel or soft cloth.

If the eruption is mild, use a low-potency steroid such as hydrocortisone 2.5% cream or ointment twice daily to affected areas and apply a generous coating of a petrolatum (Aquaphor or Vaseline) or a zinc oxide-based ointment (Balmex, Triple paste, or A&D ointment) over the topical steroid to the affected areas of skin at each diaper change.

Stronger topical steroids such as desonide 0.05% (class 6), hydrocortisone valerate 0.02% cream (class 5), or ointment (class 4) may be used for brief periods when necessary.

Potent topical steroids, particularly fluorinated preparations such as those contained in Lotrisone, are to be avoided in the diaper area.

If there is no improvement after several days and the presence of C. albicans is suspected, a topical antifungal preparation such as Triple Paste AF or Vusion ointment (0.25% miconazole combined with 15% zinc oxide) should be used.

Keep skin of diaper area clean and dry.

Change diapers promptly after voiding or soiling.

Minimize friction—dry the skin by patting (not rubbing). Remember friction is one of the causes of irritant diaper dermatitis.

Absorb moisture—use of disposable diapers with super absorbent gelling materials holds moisture in and keeps it away from the skin.

Use gentle, soap-free cleansers such as Cetaphil nonsoap gentle cleanser.

Apply a skin protectant/barrier cream to the skin at each diaper change. Recommended creams: Aquaphor, Triple paste, or Desitin.