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pH. The rise in pH increases the activity of fecal proteases and lipases, which can
damage skin.
C. albicans is found on the skin in 40% of infants with active diaper dermatitis
within 72 hours of the appearance of the rash. Because studies show that this
organism is present in less than 10% of infants without diaper dermatitis, it may
be playing a significant role. Sources of C. albicans include the GI tract and
secondary implantation from a mother with candidal vaginitis.

FIGURE 69.12 Distribution of atopic eczema at various ages.


FIGURE 69.13 Infant with irritant/contact diaper dermatitis.

Another consideration is the predisposition of certain individuals to react more
easily and negatively to varying irritants. There are instances of true allergic
contact dermatitis from baby wipes and dyes and fragrances found in diapers.
Allergies to dyes usually occur at the waist band, the area that fits tightly around
the leg, and in the center of the diaper, sparing the folds. If this is a concern, then
switching to dye-free and fragrance-free diapers and using water or soft cloths
with water instead of traditional disposable wipes may help. Generally, infants
with an atopic or seborrheic predisposition are at greater risk for the development
and persistence of diaper dermatitis. Differentiation of the various types of diaper
dermatitis is difficult. Clues from the history and physical examination are
necessary when characterizing the cause of this problem. The different types of
diaper rashes include occlusion dermatitis, atopic dermatitis, seborrheic


dermatitis, candida diaper dermatitis, and mixed dermatitis. Acrodermatitis
enteropathica, which is caused by zinc deficiency, psoriasis, and Langerhans cell
histiocytosis, should also be considered in the differential diagnosis for diaper
dermatitis that is persistent or does not respond to antifungals and antiinflammatory medications.

Treatment is determined by the cause of the dermatitis. In general, optimized
skin care, which includes decreased frequency of washing, use of mild soaps, and
use of barrier emollients, will help with any diaper dermatitis. With occlusive
dermatitis, avoidance of tightly fitting diapers, plastic-covered paper diapers, and
rubber pants is important. When atopic dermatitis is present, the use of topical
steroids is necessary. It is important to avoid fluorinated or other potent steroids
in the diaper area because occlusion by the diaper enhances the steroid effect and
is more likely to produce skin atrophy and striae. Antifungal–steroid
combinations should also be avoided for these same reasons. Therefore, 1% or
2.5% hydrocortisone cream or ointment no more than twice daily over a short
period (5 to 7 days) is recommended. Hydrocortisone (1% or 2.5%) is also
effective for seborrheic diaper dermatitis and can be used intermittently. With
candidal diaper dermatitis, the use of preparations such as econazole, miconazole,
or nystatin twice daily is effective. If thrush is also present, oral nystatin
suspension, 200,000 units (2 mL) four times a day for 7 days, is advisable. This
medication will also be useful if the infant is seeding C. albicans from the GI
tract onto the skin of the diaper area. Secondarily infected dermatitis, such as
bullous impetigo, should be treated with the appropriate systemic antibiotics or in
some cases topical antibiotics.

Atrophic Patches
Aplasia Cutis
Aplasia cutis is a congenital defect that is characterized by localized absence of
epidermis and dermis and, sometimes, subcutaneous fat. It generally occurs on
the scalp (80% near the hair whorl) but can occur on any location of the body.
Right after birth, aplasia cutis can appear as a scar or as a weeping, granulating
oval or circular defect. Small defects are the most common but larger ones
sometimes occur and may extend to the dura or meninges. Some lesions may
present with an almost bullous appearance and when surrounded by dark hair or
thicker hair (hair collar sign) may represent a form of neural tube defect. Patients

with these lesions should undergo an MRI of the brain to look for underlying
connection to the brain. Congenital absence of skin can also be seen with


epidermolysis bullosa. Antithyroid drugs, most notably methimazole, have been
implicated in some cases of aplasia cutis congenita.

Indurated Plaques
Subcutaneous Fat Necrosis
Subcutaneous fat necrosis is a condition seen in usually term infants with the
development of freely mobile nodules and plaques with or without redness. They
usually appear within the first 6 weeks of life and are usually limited to areas of
trauma or ischemia during delivery. These can be asymptomatic or mildly tender.
Risk factors include high birth weight, prolonged labor, neuroprotective cooling,
and other ischemia. The most common locations are the back, buttocks, and
cheeks. Lesions resolve spontaneously in weeks to months. Mild atrophy of the
skin may be noted after resolution. Complications include hyper- or
hypocalcemia, lactic acidosis, high levels of ferritin, and transient
thrombocytopenia; hypercalcemia is the most common. For extensive lesions,
serum calcium, phosphorus, parathyroid hormone, and vitamin D levels should be
monitored and patients should be observed closely for irritability, vomiting,
anorexia, renal failure, or failure to thrive in the first 6 months. Pamidronate and
low-calcium formula are used in severe cases. In most cases, reassurance is all
that is needed.

Vascular Patches/Plaques and Hamartomas
Acute Hemorrhagic Edema of Infancy
Acute hemorrhagic edema of infancy is a distinctive, cutaneous small-vessel
leukocytoclastic vasculitis of young children. Dark purple or pink in color,
somewhat annular patches and plaques, without surface change, occur mostly on

the face and extremities ( Fig. 69.14 ). Infants otherwise look well and are usually
afebrile or at most have a low-grade fever. Visceral involvement is uncommon,
and spontaneous recovery usually occurs within 1 to 3 weeks without sequelae.
The main differential diagnosis is Henoch–Schönlein purpura.