Irritant diaper dermatitis
(IDD, also called a diaper/nappy rash) is a generic term applied to
skin rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cr ...
in the
diaper nappy
A diaper /ˈdaɪpə(r)/ (American and Canadian English) or a nappy (Australian English, British English, and Hiberno-English) is a type of underwear that allows the wearer to urinate or defecate without using a toilet, by absorbing or contai ...
area that are caused by various skin disorders and/or irritants.
Generic irritant diaper/nappy dermatitis is characterized by joined patches of
erythema
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not asso ...
and scaling mainly seen on the
convex
Convex or convexity may refer to:
Science and technology
* Convex lens, in optics
Mathematics
* Convex set, containing the whole line segment that joins points
** Convex polygon, a polygon which encloses a convex set of points
** Convex polytop ...
surfaces, with the
skin fold
Skin folds or skinfolds are areas of skin that are naturally folded. Many skin folds are distinct, heritable anatomical features, and may be used for identification of animal species, while others are non-specific and may be produced either by ind ...
s spared.
Diaper/nappy
dermatitis
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...
with secondary
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
l or
fungal
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
involvement tends to spread to
concave
Concave or concavity may refer to:
Science and technology
* Concave lens
* Concave mirror
Mathematics
* Concave function, the negative of a convex function
* Concave polygon, a polygon which is not convex
* Concave set
* The concavity of a ...
surfaces (i.e. skin folds), as well as convex surfaces, and often exhibits a central red, beefy
erythema
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not asso ...
with satellite
pustules
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...
around the border.
It is usually considered a form of
irritant contact dermatitis
Irritant contact dermatitis is a form of contact dermatitis that can be divided into forms caused by chemical irritants and those caused by physical irritants.
Chemical
Chemical irritant contact dermatitis is either acute or chronic, which is u ...
. The word "diaper" is in the name not because the diaper/nappy itself causes the rash but rather because the rash is associated with diaper use, being caused by the materials trapped by the diaper (usually
feces).
Allergic contact dermatitis
Allergic contact dermatitis (ACD) is a form of contact dermatitis that is the manifestation of an allergic response caused by contact with a substance; the other type being irritant contact dermatitis (ICD).
Although less common than ICD, ACD is ...
has also been suggested, but there is little evidence for this cause.
In adults with incontinence (
fecal
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
,
urinary
The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, co ...
, or both), the rash is sometimes called incontinence-associated dermatitis (IAD).
The term
diaper candidiasis
Candidiasis is a Fungal infection in animals, fungal infection due to any type of ''Candida (genus), Candida'' (a type of yeast). When it Oral candidiasis, affects the mouth, in some countries it is commonly called thrush. Signs and symptoms in ...
is used when a fungal origin is identified. The distinction is critical because the treatment (
antifungals
An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryp ...
) is completely different.
Causes
Irritant diaper dermatitis develops when skin is exposed to prolonged wetness, increased skin
pH caused by the combination, and subsequent reactions, of
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellular ...
and
feces, and resulting breakdown of the
stratum corneum, or outermost layer of the skin.
This may be due to
diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
, frequent stools, tight diapers, overexposure to
ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
, or
allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
s. In adults, the stratum corneum is composed of 25 to 30 layers of flattened dead
keratinocytes
Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells.
Basal cells in the basal layer (''stratum basale'') of the skin are sometimes referre ...
, which are continuously shed and replaced from below. These dead cells are interlaid with
lipids
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...
secreted by the
stratum granulosum
The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis lying above the stratum spinosum and below the stratum corneum ( stratum lucidum on the soles and palms).James, William; Berger, Timothy; Elston, Dirk (2005) '' ...
just underneath, which help to make this layer of the skin a waterproof barrier. The stratum corneum's function is to reduce water loss, repel water, protect deeper layers of the skin from injury, and to repel
microbial invasion of the skin. In infants, this layer of the skin is much thinner and more easily disrupted.
Urine
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
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
alone is only a mild skin irritant, when
urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid.
Urea serves an important ...
breaks down in the presence of fecal
urease
Ureases (), functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous bacteria, fungi, algae, plants, and some invertebrates, as well as in soils, as a soil enzyme. They are nickel-contai ...
it increases pH because ammonia is released, which in turn promotes the activity of
fecal
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
enzymes such as
protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...
and
lipase.
These fecal enzymes increase the skin's hydration and permeability to
bile salts
Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts.
Primary b ...
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
A cloth diaper (American English) or a cloth nappy or real nappy or a reusable nappy (Australian English and British English) is a reusable diaper made from natural fibers, man-made materials, or a combination of both. They are often made ...
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)." 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.
Diet
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. 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.
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
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...
, which affect the
intestinal microflora. Also, there is an increased incidence of diaper rash in infants who have had
diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
in the previous 48 hours, which may be because fecal enzymes such as
lipase and
protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...
are more active in feces which have passed rapidly through the
gastrointestinal tract.
Secondary infections
The significance of
secondary infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...
in IDD remains controversial. There seems to be no link between presence or absence of IDD and microbial counts.
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.
A wide variety of infections has been reported, including ''
Staphylococcus aureus,
Streptococcus pyogenes
''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus '' Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They ...
,'' ''
Proteus mirabilis
''Proteus mirabilis'' is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus'' infections in humans. It is widely distributed in soil and ...
'',
enterococci
''Enterococcus'' is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical charac ...
and ''
Pseudomonas aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aerug ...
'', but it appears that ''
Candida'' is the most common opportunistic invader in diaper areas.
Diagnosis
The diagnosis of IDD is made clinically, by observing the limitation of an erythematous eruption to the convex surfaces of the genital area and buttocks. If the diaper dermatitis occurs for greater than 3 days it may be colonized with ''
Candida albicans
''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...
'', giving it the beefy red, sharply marginated, appearance of
diaper candidiasis
Candidiasis is a Fungal infection in animals, fungal infection due to any type of ''Candida (genus), Candida'' (a type of yeast). When it Oral candidiasis, affects the mouth, in some countries it is commonly called thrush. Signs and symptoms in ...
.
Differential diagnosis
Other rashes that occur in the diaper area include
seborrhoeic dermatitis
Seborrhoeic dermatitis, sometimes inaccurately referred to as seborrhoea, is a long-term skin disorder. Symptoms include red, scaly, greasy, itchy, and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the ...
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
The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back.
Structure
The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic:
* S: The ski ...
(
cradle cap
Cradle cap or cradle hat causes crusty or oily scaly patches on a baby's scalp. The condition is not painful or itchy, but it can cause thick white or yellow scales that are not easy to remove. Cradle cap most commonly begins sometime in the fir ...
) but can also appear in the inguinal folds.
*Atopic dermatitis, or
eczema
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...
, is associated with
allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
, often
hereditary. This class of rashes may appear anywhere on the body and is characterized by intense
itch
Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasant ...
iness.
Treatments
Possible treatments include minimizing diaper use, barrier creams, mild topical cortisones, and antifungal agents. A variety of other inflammatory and infectious processes can occur in the diaper area and an awareness of these secondary types of diaper dermatitis aids in the accurate diagnosis and treatment of patients.
Overall, there is sparse evidence of sufficient quality to be certain of the effectiveness of the various treatments. Washcloths with cleansing, moisturising and protective properties may be better than soap and water, and skin cleansers may also be better than soap and water, but the certainty of evidence with regard other treatments is very low.
Diaper changing
The most effective treatment, although not the most practical one, is to discontinue use of diapers, allowing the affected skin to air out. Another option is simply to increase the frequency of diaper changing.
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.
Diaper type
Some sources claim that diaper rash is more common with cloth diapers.
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. However, there may not be enough data from good-quality, randomized controlled trials to support or refute disposable diaper use thus far. Furthermore, the effect of non-biodegradable diapers on the environment is a concerning matter for public policy.
Creams, ointments
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
Polydimethylsiloxane (PDMS), also known as dimethylpolysiloxane or dimethicone, belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, as i ...
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
Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement ...
-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.
A 2005 meta-analysis found no evidence to support the use of topical vitamin A to treat the condition.
Dangers of using powders
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.
Antifungals
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
Hydrocortisone is the name for the hormone cortisol when supplied as a medication. Uses include conditions such as adrenocortical insufficiency, adrenogenital syndrome, high blood calcium, thyroiditis, rheumatoid arthritis, dermatitis, asthm ...
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.
References
External links
{{Diseases of the skin and subcutaneous tissue
Diapers
Babycare
Eczema