Diaper Dermatitis

Etiology

Diaper dermatitis is an inflammatory reaction of the skin around the diaper area. It results due to a combination of multiple factors such as increased moisture, prolonged contact with urine or feces, and other irritants like detergents.[2]

 The second most common cause of diaper dermatitis is infection. Fungal infection, especially by Candida albicans, is the most common infectious cause. Candida infection can be a primary cause of diaper dermatitis and can also result as a superimposed infection to chronic irritation. Other mycoses that can be associated with diaper dermatitis include dermatophytosis, exacerbation of seborrheic dermatitis by Malassezia, and other pseudomycotic conditions like erythrasma.[3]

 Bacterial infections follow fungal as the second most common cause of infectious diaper dermatitis. Staphylococcus aureus infection can occur in newborns, secondary to colonization from the umbilical cord. Streptococcus pyogenes is also seen as an etiologic agent causing the condition.[4]

Epidemiology

Diaper dermatitis can affect any individual using diapers without any gender preference. Newborns and infants are at an increased risk due to skin immaturity. Peak incidence is around 9 to 12 months of age. Diaper dermatitis occurs in about 50% of infants, and it accounts for about 25% of visits to primary care physicians related to dermatologic complaints in the first year of life.[5]

There are risk factors associated with the development of diaper dermatitis, such as:

• Age: newborn and infant skin are more immature and show increased susceptibility.
• Diet: changes in diet as the infant grows are related to changes in intestinal microbiota and stool pH. Breastfeeding has been proven to be a protective factor.
• Frequency of diaper changes: prolonged contact with irritants such as urine and feces increases the risk of skin inflammation. Newborns and young infants whose diapers are changed more frequently tend to be less affected than older infants.[6]

Pathophysiology

The most important predisposing factor for diaper dermatitis is the increased moist that results from wearing diapers, which leads to increased friction and maceration, which makes the skin more susceptible to damage and penetration by skin microorganisms and other irritants.[7][6]

Changes in skin pH also play an essential role; an increase in pH around the diaper area from the breakdown of urinary urea can, in turn, increase fecal enzyme activity that can further damage the skin.[8][9] The combination of these processes results in colonization and infection from organisms such as Staphylococcus aureus, Streptococcus pyogenes, and Candida albicans.

History and Physical

The presentation may begin with a history of increased frequency of stools or changes in its appearance (loose), followed by the development of erythema around the diaper area about two days after. Physicians must elicit from parents hygiene practices, frequency of diaper changes, type of diapers used, and use of any substance that may be worsening the irritation.

Clinical presentation can be variable. Skin findings include erythema, papules, scaling, and erosions that can be present around the thighs, scrotum, suprapubic area, and buttocks. It usually spares skin creases.[6]

Candida dermatitis presents with erythema and scaly plaques, accompanied by edema. The most characteristic feature is the presence of satellite pustules or papules. Candidal dermatitis can be present in the skin folds.  In severe cases, erosions and ulceration can occur.[3]

Clinical manifestation of S. aureus infection can range from small papules and pustules to large, fragile blisters of bullous impetigo. S. pyogenes presents with fiery-red erythema and maceration that involves the skin folds.[4]

Evaluation

Diaper dermatitis is a clinical diagnosis based on history and physical examination findings. Overall, there is no need to perform any laboratory testing. However, when considering infection by Candida albicans, confirmation of the diagnosis by examination with KOH can be useful, although not necessary. If there is suspicion of bacterial infection, Gram staining can be performed.[3]

Treatment / Management

Management of diaper dermatitis has two main goals: healing of damaged skin and prevention of rash recurrence.

The strategies to achieve these goals include:

• Good hygiene is essential to maintain skin integrity and prevent further breakdown. Reducing the exposure to irritants, like urine and feces, can be achieved with frequent diaper changes and using superabsorbent diapers that help reduce skin over-hydration.
• Bathing and cleaning the diaper area with water and a soap-free cleanser.
• The use of wet wipes has been controversial over the years, mainly due to the concern that the components could cause further irritation to the skin. However, recent studies have shown that baby wipes do not cause any harm to the skin. Furthermore, the newer formulations of wipes that include pH buffers help to balance the alkaline pH of the urine and prevent skin damage due to pH changes. It is important to advise parents that the wipes should be free of soap, essential oils, or other fragrances and harsh detergents that can be irritant to the skin.[10]
• The use of topical emollients is recommended for both prevention and treatment. They can improve the skin barrier function, and they also provide a barrier between the skin and the diaper, urine, and feces, not limiting the contact with the skin and diminishing irritation, but also preventing over-hydration to the skin. For the management of current diaper dermatitis, apply with each diaper change. Examples of emollients available include zinc oxide, petrolatum, cod liver oil, lanolin, among others.[10]
• For cases of diaper dermatitis that do not improve within 2 to 3 days of implementing the measures above, or in moderate to severe cases, a short course of low-potency corticosteroids can be used. Hydrocortisone 0.5% 2 times a day for one week.[3]
• When treating candida diaper dermatitis, topical antifungals should be added to the regimen. Nystatin can be used first, applied with every diaper change, with a generally good response; however, if by 1 to 3 days, there is no improvement of symptoms (also keeping in mind Candida resistance to nystatin), switching to azoles is recommended. Clotrimazole, miconazole, or ketoconazole can be used, applied twice a day for 7 to 10 days. 
• In cases of bacterial infection, topical antibiotics may be necessary. And in cases of severe infections, such as perianal streptococcal dermatitis, oral antibiotics are indicated.[10]

Differential Diagnosis

The differential diagnosis of diaper dermatitis includes any skin condition that can present around the diaper area.

• Seborrheic dermatitis usually presents in the first month of life. Characterized by skin erythema and scaling, that begins in the scalp and distributes to the face. It has the potential to spread to the diaper area, making babies more susceptible to the development of irritant diaper dermatitis.[6]
• Atopic dermatitis usually presents between 3 and 12 months of age. The presentation includes extreme pruritus with dryness and erythema. Lesions typically involve skin flexures. The diaper area is generally spared.[6]
• Allergic contact dermatitis, secondary to reactions to fragrances or preservatives. It usually occurs after the introduction of a new skin product, and it involves any part of the skin where the product was applied.[5]

 Other differential diagnoses that need to be taken into consideration include tinea cruris, scabies, acrodermatitis enteropathica, biotin deficiency, Langerhans cell histiocytosis (Letterer-Siwe disease), congenital syphilis, Kawasaki disease, and HIV infection.[11][12] 

Prognosis

Diaper dermatitis has an excellent prognosis with appropriate diagnosis and with timely adequate management. It is usually a mild, self-limiting disease.

Complications

Complications of irritant diaper dermatitis include superimposed infection either with fungal or bacterial microorganisms. Special consideration must be taken when these infections occur in immunocompromised patients since they are at risk of invasive disease.[13]