Similar to the patient who presents with multiple trauma, a child with a life-threatening dermal exposure can pose a dramatic challenge. Health care providers must not solely concentrate on the exposure and neglect the fundamentals of resuscitation. Furthermore, unlike in the case of the trauma patient, health care providers must follow hazardous materials (HAZMAT) procedures and policies for their own protection (Chapter 8) (1). The primary objective in decontamination is to rapidly remove the offending toxin, because, typically, the longer the contact, the greater the absorption. Fortunately, with nearly all dermal exposures, the aphorism “the solution to the pollution is dilution” is valid.

The skin is an extremely effective barrier to potentially toxic compounds. The ability of the skin to act as a barrier depends on the relative maturity and thickness of the epidermis, dermis, subcutaneous fat, and appendices (Fig. 128.1A) (2,3,4).

The epidermis is composed of four layers, which form a tough, water-insoluble covering. The rate-limiting step in the penetration of the skin for most substances is diffusion through the outermost layer (stratum corneum) (5). Because the dermis is more permeable than the epidermis, any disruption of the epidermis may lead to greater tissue injury and absorption. The thickness of the stratum corneum varies with age and location on the body (Fig. 128.1B). The preterm infant does not have a fully formed stratum corneum and is more susceptible to dermal absorption (2,3,5). Plantin et al. noted that dermal permeability is increased in premature infants but falls steadily until approximately the age of 10 days (6). The newborn infant has an average dermal thickness of 1.2 mm, compared with an average thickness of 2.1 mm in an adult (2). Epidermal and dermal thickness also differs in various areas of the body. Rates of absorption correlate proportionately with these variations (7). Vanrooij et al. showed that absorption of polyaromatic hydrocarbons was 69% greater in the groin compared to the palm. (Fig. 128.2) (8).

The dermis and subcutaneous fat, the two deeper layers of the skin, mainly act as a fibrous envelope and as an insulator. These layers and the deeper layers of the epidermis are rich in enzymes and can modify chemicals that penetrate the stratum corneum. The skin is capable of phase I oxidative, phase II conjugation, reduction, and hydrolytic reactions (8,9,10). Sweat gland ducts and hair follicle orifices may enable toxins to penetrate the skin. Their concentration also varies with age and anatomical site. The adult forehead has approximately 900 follicles per square centimeter, compared with none on the palms and soles.

The pediatric patient is more susceptible than the adult patient to suffering injury from dermal exposures, not only because of the differences in the structure of the skin but also because of the higher proportion of body surface area to body weight (11). Wester et al. showed that the neonate exhibits roughly three times greater absorption rates than the adult for an equal amount of exposure (12). Because infants have much less keratin in their skin, they are more susceptible to vesicants and caustics than are adults (13,14). Table 128.1 summarizes important factors that may enhance toxin absorption.

The goals of decontamination are to prevent both absorption and systemic toxicity. No absolute contraindications exist for dermal decontamination. Life-saving procedures, however, should not be delayed by the need for skin decontamination.