Dermatology for the pediatrician: Advances in diagnosis and treatment of common and not-so-common skin conditions
ABSTRACTAdvances have been made in understanding and treating both common and rare dermatologic conditions. Atopic dermatitis benefits from bathing and ceramide moisturizers. Common allergic contact dermatitis may have specific presentations. Tinea capitis is effectively treated with terbinafine. Infantile hemangiomas should be treated early in the disease course and respond well to propranolol; any white sign of ulceration should be noted. Localized alopecia areata responds well to topical clobetasol, avoiding the need for intralesional injections. Topical rapamycin can be used to treat tuberous sclerosis. Further understanding of genetics will help guide pediatricians to the proper diagnosis and treatment of skin conditions.
ALOPECIA AREATA
Intralesional steroids have been the gold standard of treatment for localized alopecia areata. However, for children who cannot tolerate the injections, can topical steroids achieve enough penetrance to reduce lesion duration? A recent study compared twice-daily application of clobetasol propionate 0.05% cream or hydrocortisone 1% cream for 6 weeks on followed by 6 weeks off for 24 weeks in children with alopecia areata affecting at least 10% of scalp surface area. The clobetasol cream was superior in terms of decreasing alopetic surface area compared with hydrocortisone.22 In reference to the efficacy of clobetasol cream, only localized alopecia areata showed this response, and not alopecia totalis or universalis.
RELATIVELY RARE DIAGNOSES
Epidermal nevi
Epidermal nevi size and phenotype have guided treatment decisions when evaluating these lesions. It is believed that epidermal nevi are due to RAS/MAPK mutations, and further examination of genetic causes has become increasingly important. If the genetic mutation is known, clinical signs and genetic testing can be used to monitor children for conditions potentially related to this mosaic disorder, and to properly diagnose and treat the lesions.
Recently, researchers have been able to explain why some children with large epidermal nevi develop hypophosphatemic rickets and others do not. Mutations in HRAS or NRAS can lead to an increase in fibroblast growth factor-23, resulting in this bone abnormality.23
Tuberous sclerosis
Tuberous sclerosis (TS) is remarkable for noncancerous lesions occurring in skin, brain, kidneys, nervous system, heart, lungs, or retina. Skin presentations include patches of light-colored skin, thickened skin, growths under the nails, and facial lesions that resemble acne. Ash leaf or café au lait macules may occur, as well as large plaque angiofibromas.
While oral rapamycin has been used to treat internal tumors related to TS, a low-dose topical formula has been shown effective for treating facial angiofibromas of TS.24 This new therapy is important given the impact of facial anomalies on psychosocial development. In addition, topical rapamycin avoids the need for laser treatment, which is more painful and less effective.
SUMMARY
The understanding of common and rare skin conditions has increased during the past decade. Studies in dermatologic diagnoses and treatment have produced new insights into genetic mutations, including those involved in the development of epidermal nevi. Serendipitous findings, such as the use of propranolol for infantile hemangiomas, have also occurred. These advances have allowed for greater diagnostic accuracy and better treatments. Less invasive treatment strategies also have been developed, including clobetasol cream for localized alopecia areata and topical rapamycin for tuberous sclerosis, and these have led to greater compliance, fewer treatment-related adverse effects, and more efficacious outcomes.
