Salient features
·
Frequently, an irritant dermatitis
of the diaper area due to occlusion and prolonged exposure to urine and feces
·
Secondary infection with Candida albicans often occurs
·
May be associated with seborrheic
dermatitis and psoriasis
Epidemiology
Diaper dermatitis develops in at least 50% of
infants, and it is responsible for a considerable percentage of dermatologic
consultations in infants and toddlers. Seborrheic dermatitis is a predisposing
factor.
Pathogenesis
Diaper dermatitis is the
cumulative result of several factors, in particular dampness and exposure to
urine and feces. In the past, ammonia derived from the urea in urine was held
as primarily responsible for diaper dermatitis. More recently, the blame has
been placed on the (alkaline) pH of the urine and the role of fecal bacteria.
Enzymes produced by fecal bacteria, as well as residual pancreatic proteases
and lipase in the stool, act as irritants and these enzymes are also activated
in the alkaline milieu. In addition, ureases are produced by fecal bacteria,
resulting in a further increase of the urinary pH. This explains why diaper
dermatitis is more likely to appear in cow milk-fed than in breast-fed infants:
cow milk formulas are colonized by a greater number of urease-producing
bacteria.
Prolonged use of
diapers, dampness, and the factors detailed above leads to the breakdown of the
horny layer barrier function. An alkaline pH also facilitates the development
of secondary C. albicans infection.
As diaper dermatitis
tends to be most prominent on the inner parts of the thighs, genitalia and
buttocks, friction between the skin and the diaper material likely acts as a
physical factor that leads to further irritation. In addition, chemical
constituents of the diaper and/or topical preparations and baby wipes may lead
to contact sensitization.
Clinical features
Diaper dermatitis is
strictly confined to the diaper area, presenting with mild to pronounced
erythema, erosions, and scaling. In the common form due to irritant contact
dermatitis, genitocrural folds are typically spared. Depending on whether there
is a secondary infection or an underlying dermatosis (e.g. seborrheic
dermatitis, psoriasis), the clinical picture can vary.
Differential diagnosis
While the most common etiologies are
irritant contact dermatitis, cutaneous candidiasis and seborrheic dermatitis,
patients often have a combination with one disorder superimposed on another.
Discrete papules or nodules are seen in scabies, granuloma gluteale infantum
and perianal pseudoverrucous papules, whereas congenital syphilis often
presents with erosions and even ulcerations. *Potential allergens include
sorbitan sesquioleate (an emulsifier in diaper balms), fragrances, disperse
dyes, rubber additives (e.g. mercaptobenzothiazole), and preservatives in baby
wipes (e.g. iodopropynyl butylcarbamate).
Treatment
In the acute phase, mild
corticosteroid preparations are helpful. Topical imidazole creams are added for
secondary infection with Candida spp.
The major goal of long-term management is avoidance of the causative factors.
Frequent changing of highly absorbent disposable diapers is associated with a
lower incidence and severity of diaper dermatitis, and it leads to a more
physiologic pH. Emollients containing white paraffin (Vaseline®) or soft zinc pastes provide both protective and
soothing effects.
