Much to consider when treating diaper dermatitis

September 2006

This month’s Pharmacology Consult column will review the treatment of a common disorder affecting infants and young children, diaper dermatitis.

Diaper dermatitis (DD), an acute inflammatory skin reaction of the diaper area, is the most common skin disorder to affect infants. Data from the National Ambulatory Medical Care Survey between 1990 and 1997 reveal that 600,000 to 1 million visits occurred each year to ambulatory physicians for infants and children with DD. This prevalence rate translates to a 25% risk for an infant or child to be diagnosed with DD. Ninety-five percent of these children were diagnosed and treated by primary care physicians (75% by pediatricians and 20% by family physicians). However, DD occurs much more frequently, as less than 10% of episodes are referred for treatment.

Several factors are responsible for the development of DD. A key factor is occlusion of the skin under the diaper. Increased hydration and maceration of the stratum corneum, the most superficial layer of the skin, occurs. Chafing and friction, a rise in skin pH (toward more alkaline, due to ammonia) and digestive stool enzymes (lipase, trypsin) also contribute to the development of DD. These changes increase the likelihood of infection with fungal or bacterial pathogens. In healthy infants without DD, Candida albicans is rarely found in the diaper area. However, in infants with DD for three days or longer, 80% will harbor C. albicans. The diaper area may also become secondarily infected with bacterial pathogens, with Staphylococcus aureus, Streptococcus, E. coli, Peptostreptococcus and Bacteroides, the most common.

Skin protectants

The treatment of DD includes non-drug therapy and pharmacotherapy. Non-drug therapy includes frequent diaper changes and appropriate washing and drying of the diaper area. Skin protectants are the mainstay pharmacotherapeutic agents used in the treatment of DD. Ingredients in these products protect the skin from further irritation and promote healing of damaged skin.

The FDA identified a number of ingredients effective in the treatment of DD. A variety of over-the-counter (OTC) products are available to consumers that contain these ingredients, usually with more than one effective ingredient included. Some products additionally contain other ingredients, which have not been proven to be effective (eg, aloe, castor oil, goldenseal, Peruvian balsam, vitamins A and D, vitamin E, with hazel). Products containing boric acid should not be used, as topical application of boric acid has been associated with significant systemic absorption and toxicity. The addition of vitamins to some products (eg, A and D ointment) provides no beneficial effect, despite the potential appeal to caregivers of including vitamins in the product. These products all contain other ingredients such as zinc oxide or petrolatum; these are the ingredients that provide the product’s therapeutic effect.

Caregivers can choose from many OTC products to treat their child’s DD. These products vary considerably in price. For example, one product has a retail price of $30 and contains 13% zinc oxide as the only active ingredient. Another product, selling for $8, includes only petrolatum as the active ingredient. By comparison, generic petrolatum can be purchased for two or three dollars. These products can be made more appealing to caregivers by including colorful packaging and product names. Among the least costly products are generic petrolatum (ie, generic Vaseline) and zinc oxide paste, which are both excellent protectants.

Zinc oxide paste contains zinc oxide, cornstarch, and petrolatum and is available in generic formulations; thus, it is an inexpensive, effective product to use. A disadvantage of zinc oxide paste is its thick consistency, which can be difficult to remove from skin as well as clothing, bedding or carpet. Mineral oil can aid in the removal of zinc oxide from skin. Some products contain zinc oxide formulations (ie, creamy ointments) that are easier to apply and remove.

Talc and cornstarch powders, while effective ingredients, must be used cautiously, as inhalation of the powder by the infant may result in respiratory distress. Products containing talc or cornstarch should be handled and applied away from the infant’s face, avoiding aerosolization as much as possible. Despite some clinician’s fears, controlled studies have shown that cornstarch does not promote yeast infection or fermentation to alcohol.

Antifungal agents

When DD is secondarily infected with fungal pathogens, treatment with a topical antifungal agent is beneficial. Because the FDA does not advise caregivers to treat fungal DD without the supervision of a physician, OTC topical antifungal products cannot claim that they are indicated for the treatment of DD. However, clinicians commonly use antifungal products. The National Ambulatory Medical Care Survey from 1990-1997 found that nystatin and clotrimazole were the most commonly prescribed drugs to infants and children with DD, prescribed in 43% of the cases.

Other topical antifungal products are available, both OTC and by prescription, and they are all likely to be effective therapy when fungal pathogens are present. A new antifungal combination product available by prescription only was recently introduced. The product, Vusion (Barrier Therapeutics), contains miconazole, zinc oxide and white petrolatum. Vusion is labeled for use in infants aged 4 weeks and older with candidiasis DD. The combination may make this product convenient, but it is more expensive when compared with separate use of the individual ingredients.

Topical corticosteroids

The use of a topical corticosteroid may be necessary in moderate-severe cases of DD when significant inflammation occurs. Although topical corticosteroids may be effective therapy, the misuse of topical corticosteroids is frequently discussed in published literature. Relevant information includes the potential for systemic absorption of topically applied corticosteroids. The ratio of body surface area to body weight is significantly higher for infants, and the diaper area represents a relatively large surface area.

Factors contributing to enhanced drug absorption from topical administration are present in DD, including the application of a drug to occluded skin (occlusion enhances drug penetration through the skin by increasing skin hydration) and the presence of non-intact skin (drug absorption is enhanced when the stratum corneum is not intact). Thus, the potential for significant systemic absorption of a topically applied corticosteroid exists. Because of this, only low potency corticosteroid agents are recommended for the treatment for DD. Pharmacologic potency for topical corticosteroids is classified into seven categories: Groups 1 and 2 are considered high potency (eg, betamethasone dipropionate); Groups 3 and 5 are considered mid-potency (eg, triamcinolone acetonide, betamethasone valerate, or mometasone furoate,); and Groups 6 and 7 are considered low potency (eg, hydrocortisone).

There is some evidence that clinicians may not always be cognizant of the different potency of topical corticosteroid agents, nor of their potential for significant adverse effects. Railan and colleagues surveyed 106 pediatricians in attendance at the AAP 1999 National Conference to examine the appropriateness of pediatricians’ use of clotrimazole-betamethasone diproprionate, C-BMV (Lotrisone). Twenty-three percent of those surveyed prescribe C-BMV for patients with DD. Only 18% correctly identified C-BMV as a high-potency topical corticosteroid. Data from the National Ambulatory Medical Care Survey (1990-1997) reveal that C-BMV was the fifth leading agent used in the treatment of DD and was prescribed in 6.2% of visits.

Adverse effects that may result from topical application of corticosteroids include skin atrophy, striae, or hypothalamus-pituitary-adrenal (HPA) axis suppression. Case reports of skin atrophy and striae have been published. These effects are more likely with prolonged (greater than 2 weeks) use and application of higher potency corticosteroids. Results of published studies evaluating adrenal function with use of topical corticosteroids have been mixed. Some studies found no evidence of adrenal suppression with use of low or higher potency corticosteroids in infants or children with various skin disorders. However, several studies have detected laboratory evidence of adrenal suppression in infants with atopic dermatitis receiving hydrocortisone (a low potency corticosteroid). It is not clear how laboratory evidence of adrenal suppression translates to adverse clinical effects, and documented cases of clinically significant adrenal suppression from topical corticosteroid use in DD or other skin disorders are very limited. However, because of the unique characteristics of DD, the potential for these adverse effects to occur from topical corticosteroid use is important to consider.

Conclusions

Diaper dermatitis is a very common disorder affecting infants and young children. A variety of OTC drug products are available to caregivers to choose from. There are 12 ingredients determined by the FDA to be safe and effective and these products vary by these active ingredients and dosage form. Prices vary considerably, from just several dollars to $30. Zinc oxide and petrolatum may be the ingredients most commonly included in OTC products, both of which are excellent skin protectants and available as generic, inexpensive formulations. Zinc oxide paste can be difficult to apply and remove because of its sticky consistency, but “creamy” formulations are available and can be easier to use.

Unique features of DD allow the potential for clinically important local and systemic adverse effects to occur from topically applied corticosteroids. Because of this, it is recommended that when use of a topical corticosteroid is necessary, only a low potency corticosteroid agent such as hydrocortisone should be used. Topical corticosteroid use should be limited to less than two weeks. Published evidence has documented that some physicians are not familiar with topical corticosteroid potency and that potent topical corticosteroids are commonly prescribed. One product prescribed by some pediatricians, clotrimazole-betamethasone dipropionate, is not labeled for this use and should not be used in the treatment of DD.

For more information:

• Edward A. Bell, PharmD, BCPS, is a Professor of Pharmacy Practice at Drake University College of Pharmacy and a Clinical Specialist at Blank Children’s Hospital, Des Moines, Iowa.
• Ward DB. Characterization of diaper dermatitis in the United States. Archives of Pediatrics and Adolescent Medicine 2000;154:943-946.
• Railan D. Pediatricians who prescribe clotrimazole-betamethasone diproprionate (Lotrisone) often utilize it in inappropriate settings regardless of the knowledge of the drug’s potency. Dermatology Online J. 2002;8:3-9.
• Levin C. Topical corticosteroid-induced adrenocortical insufficiency. Amer J Derm. 2003;3:141-147.
• Raimer S. The safe use of topical corticosteroids in children. Pediatric Annals 2001;30:225-229.
• Mancini AJ. Skin. Pediatrics 2004;113:1114-1119.
• Gupta AK. Management of diaper dermatitis. International J Derm. 2004;43:830-834.
• Padron VA. Diaper dermatitis and prickly heat. Handbook of Nonprescription Drugs, 15th ed, 2006. American Pharmacy Association, Washington DC:765-779.