Medical phototherapy in childhood skin diseases.
Phototherapy is used for the medical care of cutaneous conditions that do not respond to topical or systemic medical agents, and for conditions that require broad exposure to UV as a stabilizing agent for disease. Numerous wavelengths and delivery devices of ultraviolet light are used in childhood. This article is a brief overview of the medical usage of phototherapy in childhood. In the neonatal nursery blue light (459-460 nm) is used to reduce bilirubin levels and prevent kernicterus. While psoralens and UVA (PUVA) has been demonstrated to be efficacious in a variety of pediatric skin conditions, narrowband UVB therapy (311 nm) has largely replaced psoralens and UVA as initial choice in full-body phototherapy for children. The latter is easier to deliver, with less resultant erythema than systemic psoralens and UVA which requires strict use of 24 hour protective eyewear. Narrowband UVB is therefore preferred for stabilization and clearance of a variety of inflammatory and autoimmune conditions especially atopic dermatitis, psoriasis and vitiligo. Conditions with lymphocytic infiltration, including mycosis fungoides, alopecia areata and pityriasis lichenoides can improve with Narrowband UVB as well. Alternatively, localized delivery of Narrowband UVB can be performed using the excimer laser (308 nm), which has been described for the therapy of vitiligo and alopecia areata in childhood. Some diseases with dermal infiltration including morphea and mastocytosis may do better with Psoralens and UVA or UVA1. Delivery of psoralens can also be performed topically for said conditions and in the setting of alopecia areata, thereby limiting UVA exposure, while retaining efficacy. Phototherapy can be a helpful adjunct in pediatric skin disease, but is limited by compliance issues. Parents can act as partners in the safe and effective delivery of phototherapy by standing outside the booth or inside with the child to ensure lack of movement and to aid in maintenance of eyewear. Choice of type of phototherapy and close monitoring, with parental partnership, is the key to successful treatment.