Hot topics in pediatric dermatology

Issue: May 2012

Three “hot topics” in pediatric dermatology have received significant attention in the past year. These include: 1) advanced knowledge regarding optimal skin care practices for infants; 2) the utilization of probiotics, wet wrap therapy and skin infections in atopic patients; and 3) the beneficial effects of topical and systemic beta-blocker therapy for infantile hemangiomas.

Sheila Fallon Friedlander

Skin care practices in infants

The pediatric and dermatologic communities have not yet reached consensus on appropriate cleansing practices for infants. A recent review by Blume-Peytavi and colleagues in a 2012 study in Pediatric Dermatology provided an extensive analysis of 14 studies of moderate to high levels of evidence pertaining to skin development and cleansing practices for babies. Infant skin has thinner layers and smaller cells than adult skin. Barrier function differs at different sites. Some areas, such as the forehead, upper leg and abdomen, possess adult transepidermal water loss (TEWL) values as early as day 2, whereas forearm skin does not reach adult levels even at 1 year of life.

Neonates have a higher surface pH, which decreases to adult levels by day 28. Sebum levels initially increase up to day 7 of life, then decline to low levels by 6 months of age. These findings support the belief that neonatal skin undergoes maturational changes and differ at different body sites. Cleansing and care practices should optimally take these differences into consideration.

There have been at least six large, well-designed studies that concluded that bathing routines are not detrimental for infants and are not superior to sponge bathing. Four studies instituted bathing before the cord fell off, and based on these studies, it was concluded that bathing at appropriate temperatures made babies more comfortable and resulted in decreased heat loss. A bathing routine did not adversely affect the skin barrier.

Six articles addressed the effects of washing agents on neonatal skin function and found that the use of syndets (pH 5.5) led to a faster approximation (lower pH) of infant skin to adult acidity. Mild cleansers do not compromise the acid mantle function of the skin, but use of alkaline soaps increased surface pH. The use of synthetic detergents daily did not appear to have negative effects on normal infantile skin.

Regarding bacterial characteristics of infantile skin, it was found that bacterial colonization occurs in the first 2 to 3 days of life in almost all infants. The type and numbers of microbial flora do not vary with the use of conventional soap, detergent bath or plain water. Bacterial and candidal colonization were not affected by skin care regimens, the use of wash gels or creams. Bathing immediately after birth did not appear to affect cord healing based on results of a study that compared washing and immersion bathing.

In summary, these studies confirmed that the structure, function and composition of infant skin varies from that of adults and continues to undergo maturational processes throughout the first year of life. Twice weekly bathing, initiated after the umbilical cord has fallen off, has no deleterious effects as measured by TEWL, skin surface pH and sebum production.

Bathing seems superior to washing. There is also evidence that bathing immediately after birth is safe for full-term infants. Skin surface pH at birth is higher (6.2 to 7.5), but decreases to adult levels (5.4 to 5.9) in the subsequent few weeks. Cleansing with mild liquid baby cleansers or syndets is comparable and may even be superior to the use of plain water alone.

Advances in atopic dermatitis

Probiotics: The latest news regarding atopic dermatitis prevention is promising regarding the use of probiotics to decrease incidence in infants. In 2008, Wickens and colleagues in the Journal of Allergy and Clinical Immunology published the results of a double blind, randomized, placebo-controlled trial that demonstrated a 48% reduction in eczema in those children who received HN001 Lactobacillus rhamnosus probiotics in the first 2 years of life. In contrast, HN019 Bifidobacterium strains showed no protective effect over placebo. Wickens’ most recent study in Clinical & Experimental Allergy followed pregnant women who were at high risk to deliver atopic children. These women received probiotics (HN001 or HN019) or placebo starting at 35 weeks, and their infants the same for the first 2 years of life. These children were followed to age 4 years. The cumulative rates of incident eczema at 4 years were 32.7% for the Lactobacillus group, 40.3% for the Bifidobacterium group, and 49.3% for the placebo group. The HR for HN001 was 0.57 (95% CI, 0.18-0.83). This second study showed that the Lactobacillus probiotic supplementation may have an enduring effect in decreasing the risk for eczema in supplemented children.

Wet wraps: Children with severe atopic dermatitis can prove a therapeutic challenge. The use of systemic treatments such as cyclosporine, azathioprine and methotrexate are sometimes required but avoided when possible due to their adverse risk profiles. Wet wrap treatment (WWT) has been utilized as a means to improve topical therapy efficacy and avoid riskier systemic agent when children fail traditional topical therapy. The treatment entails the application of a double layer of gauze, tubular bandages or even cotton pajamas, in which medication is applied to affected skin. A wet layer of material is then applied to the site, followed by a dry second layer.

Devillers and colleagues in Pediatric Dermatology recently published a practical guideline for the use of this treatment. They caution that this should not be used in children aged younger than 6 months because of concern for systemic absorption. They recommend application of topical steroids only once a day under the layers, and rewetting of the first layer every 2 to 3 hours during the day. Such treatments can be left on the skin for up to 24 hours. Treatments should not be utilized daily for more than 14 days; however, “plain Vaseline or emollient” therapy can be substituted for longer durations. Risk of such therapy includes discomfort, chills and folliculitis of an occlusive or infectious nature. Temporary systemic corticosteroid effect is also possible. In appropriate situations, such therapy can eliminate the need for riskier systemic therapies.

CA-MRSA infections in atopics

Community-associated methicillin-resistant staph infections are a growing concern, as the incidence continues to rise across the nation. Matiz and colleagues investigated the incidence in atopic dermatitis patients and found that it was less common than in non-atopic patients suffering from cutaneous staphylococcal infections. Eleven of 78 isolates (14%) from children with atopic dermatitis were resistant vs. 658 of 1,482 isolates (44%) from the general population. No clindamycin-inducible resistance was found in the atopic group, whereas 1.9% of the general population isolates displayed inducible resistance, according to the findings reported in Pediatric Dermatology. Studies from both Philadelphia and Chicago have confirmed these findings, and it therefore appears that community-associated methicillin resistance may be less of an issue for cutaneous skin infections in atopics. Cephalosporins, thus, can serve as first-line therapy for otherwise healthy children with atopic dermatitis and uncomplicated skin infections in many communities.

Propranolol as first-line therapy for symptomatic infantile hemangiomas: In 2008, Léauté-Labrèze and colleagues published in the New England Journal of Medicine their experiences with propranolol for the treatment of large facial infantile hemangiomas. In the past 3 years, more than 100 publications have documented the effectiveness of this non-selective beta-blocker in the treatment of hemangiomas, which pose a functional or significant cosmetic risk to children.

The drug is quite effective, but adverse effects that include hypoglycemia, sleep disturbance, low blood pressure and wheezing can occur. Most practitioners utilize 2 mg/kg, divided twice or three times a day, with careful attention to blood pressure and glucose intake. Very young infants are usually hospitalized for initiation of therapy, and some practitioners prefer to admit all patients for initial treatment. Most patients require prolonged therapy, and early cessation often leads to recurrence. Approximately 20% of lesions can recur after discontinuation of therapy, even when therapy exceeds 6 to 8 months, according to a study by Bagazgoitia in Pediatric Dermatology. In the past year, further evidence has confirmed the utility and relative safety of this treatment. Hogeling and colleagues conducted a prospective study documenting the efficacy of propranolol vs. placebo for infantile hemangiomas, which was published in Pediatrics. Subsequently, Bertrand and colleagues in Pediatric Dermatology noted the superiority of propranolol over systemic corticosteroids for the treatment of these vascular lesions.

Given the small but real risk of adverse effects of this beta-blocker, investigators have tested the efficacy of a topical beta-blocker, timolol, in the treatment of superficial infantile hemangiomas. Pope and colleagues performed a retrospective, multicenter, cohort study utilizing timolol gel-forming solution and found that all but one of 73 patients improved after treatment with either 0.5% or 0.1% twice daily without occlusion. This treatment is an option for patients with superficial lesions, according to the study in Pediatric Dermatology.

In summary, propranolol is now considered “first-line” therapy for significant problematic infantile hemangiomas. A dosage of 2 mg/kg divided twice or three times daily is administered and prolonged therapy is required. Very young infants are better treated initially in hospital, and all children must be monitored for blood pressure changes early in the course of therapy. Families must be warned about possible risks and rebound. Infants with superficial lesions may benefit from topical timolol therapy, administered twice daily to the lesion.

References:

Bagazgoitia L. Pediatr Dermatol. 2011;28:658-662.

Bertrand J. Pediatr Dermatol. 2011;28:649-654.

Blume-Peytavi U.Pediatr Dermatol. 2012;29:1-14.

Chakkittakandiyil A. Pediatr Dermatol. 2012; 29;28-31.

Devillers AC. Pediatr Dermatol. 2012;29:24-27.

Hogeling M. Pediatrics. 2011;128:e259-266.

Léauté-Labrèze C. N Engl J Med. 2008;358:2649-2651.

Matiz C. Pediatr Dermatol. 2011;28:6-11.

Wickens K. Clin Exp Allergy. 2012;doi:10.1111/j.1365-2222.2012.03975.x.

Wickens K. J Allergy Clin Immunol. 2008;122:788-794.

Sheila Fallon Friedlander, MD, is co-director of the Vascular Lesion and Birthmark Center at Rady Children’s Hospital and Professor of Clinical Pediatrics and Medicine at the University of California at San Diego. Dr. Friedlander is also a member of the Infectious Diseases in Children Editorial Board. Disclosure: Dr. Friedlander reports no relevant financial disclosures.