Irritant diaper dermatitis

Cloth diaper

Although wetness alone has the effect of macerating the skin, softening the stratum corneum, and greatly increasing susceptibility to friction injury, urine has an additional impact on skin integrity because of its effect on skin pH. While studies show that ammonia alone is only a mild skin irritant, when urea breaks down in the presence of fecal urease it increases pH because ammonia is released, which in turn promotes the activity of fecal enzymes such as protease and lipase.[6] These fecal enzymes increase the skin's hydration and permeability to bile salts which also act as skin irritants.

There is no detectable difference in rates of diaper rash in conventional disposable diaper wearers and reusable cloth diaper wearers. "Babies wearing superabsorbent disposable diapers with a central gelling material have fewer episodes of diaper dermatitis compared with their counterparts wearing cloth diapers. However, keep in mind that superabsorbent diapers contain dyes that were suspected to cause allergic contact dermatitis (ACD)."[9] Whether wearing cloth or disposable diapers they should be changed frequently to prevent diaper rash, even if they don't feel wet. To reduce the incidence of diaper rash, disposable diapers have been engineered to pull moisture away from the baby's skin using synthetic non-biodegradable gel. Today, cloth diapers use newly available superabsorbent microfiber cloth placed in a pocket with a layer of light permeable material that contacts the skin. This design serves to pull moisture away from the skin in to the microfiber cloth. This technology is used in most major pocket cloth diapers brands today.

The interaction between fecal enzyme activity and IDD explains the observation that infant diet and diaper rash are linked because fecal enzymes are in turn affected by diet. Breast-fed babies, for example, have a lower incidence of diaper rash, possibly because their stools have higher pH and lower enzymatic activity.[10] Diaper rash is also most likely to be diagnosed in infants 8–12 months old, perhaps in response to an increase in eating solid foods and dietary changes around that age that affect fecal composition. Any time an infant’s diet undergoes a significant change (i.e. from breast milk to formula or from milk to solids) there appears to be an increased likelihood of diaper rash.[11]

The link between feces and IDD is also apparent in the observation that infants are more susceptible to developing diaper rash after treating with antibiotics, which affect the intestinal microflora.[12][13] Also, there is an increased incidence of diaper rash in infants who have suffered from diarrhea in the previous 48 hours, which may be because fecal enzymes such as lipase and protease are more active in feces which have passed rapidly through the gastrointestinal tract.[14]

The significance of secondary infection in IDD remains controversial. There seems to be no link between presence or absence of IDD and microbial counts.[6] Although apparently healthy infants sometimes culture positive for Candida and other organisms without exhibiting any symptoms, there does seem to be a positive correlation between the severity of the diaper rash noted and the likelihood of secondary involvement.[15] A wide variety of infections has been reported, including Staphylococcus aureus, Streptococcus pyogenes, Proteus mirabilis, enterococci and Pseudomonas aeruginosa, but it appears that Candida is the most common opportunistic invader in diaper areas.[15][16][17][18]

Other rashes that occur in the diaper area include seborrhoeic dermatitis and atopic dermatitis. Both Seborrheic and Atopic dermatitis require individualized treatment; they are not the subject of this article.

• Seborrheic dermatitis, typified by oily, thick yellowish scales, is most commonly seen on the scalp (cradle cap) but can also appear in the inguinal folds.
• Atopic dermatitis, or eczema, is associated with allergic reaction, often hereditary. This class of rashes may appear anywhere on the body and is characterized by intense itchiness.

The most effective treatment, although not the most practical one, is to discontinue use of diapers, allowing the affected skin to air out.[22] Another option is simply to increase the frequency of diaper changing.[19] Thorough drying of the skin before diapering is a good preventive measure because it is the excess moisture, either from urine and feces or from sweating, that sets the conditions for a diaper rash to occur.[23]

Some sources claim that diaper rash is more common with cloth diapers.[6] Others claim the material of the diaper is relevant insofar as it can wick and keep moisture away from the baby's skin, and preventing secondary Candida infection.[24] However, there may not be enough data from good-quality, randomized controlled trials to support or refute disposable diaper use thus far.[25] Furthermore, the effect of non-biodegradable diapers on the environment is a concerning matter for public policy.[26]

Another approach is to block moisture from reaching the skin, and commonly recommended remedies using this approach include oil-based protectants or barrier cream, various over-the-counter "diaper creams", petroleum jelly, dimethicone and other oils. Such sealants sometimes accomplish the opposite if the skin is not thoroughly dry, in which case they serve to seal the moisture inside the skin rather than outside.

Zinc oxide-based ointments such as Pinxav can be quite effective, especially in prevention, because they have both a drying and an astringent effect on the skin, being mildly antiseptic without causing irritation.[20]

A 2005 meta-analysis found no evidence to support the use of topical vitamin A to treat napkin dermatitis (diaper rash).[27]

Various moisture-absorbing powders, such as talcum or starch, reduce moisture but may introduce other complications. Airborne powders of any sort can irritate lung tissue, and powders made from starchy plants (corn, arrowroot) provide food for fungi and are not recommended by the American Academy of Dermatology.[28]

In persistent or especially bad rashes, an antifungal cream often has to be used. In cases that the rash is more of an irritation, a mild topical corticosteroid preparation, e.g. hydrocortisone cream, is used. As it is often difficult to tell a fungal infection apart from a mere skin irritation, many physicians prefer an corticosteroid-and-antifungal combination cream such as hydrocortisone/miconazole.