Chapter 66: Desquamating and Hyperkeratotic Disorders in the Neonatal Period

INTRODUCTION

In the neonatal period, disorders may sometimes present with hyperkeratosis and desquamation of the skin. The differential diagnosis for hyperkeratosis and desquamation in the neonatal period is broad and includes infectious, genetic, inflammatory, immunodeficiency, and metabolic causes. Rarely, these disorders may also present with erythroderma, or generalized skin erythema affecting at least 90% of the body surface.¹ Scaling is a commonly associated symptom of erythroderma. Although the frequency of hyperkeratotic and desquamating disorders in the newborn period is unknown, the incidence of neonatal erythroderma has been estimated² to be 0.11%.

These skin changes are nonspecific and do not indicate any particular diagnosis; thus, this constellation of findings may prove to be challenging both diagnostically and therapeutically. Clinical clues and diagnostic testing can be of great importance in reaching a diagnosis. Management can be extremely challenging, as often these neonates are quite ill. Both general management principles and treatments aimed at the specific disorder are vital to the care of these babies. Despite advanced care, the mortality rate³ in these patients, particularly those with erythroderma, can approach 15%. Factors contributing to this high mortality rate are large ratio of surface area to body mass with subsequent increased transepidermal fluid loss and increased susceptibility to infection.

INFECTIOUS CAUSES

Staphylococcal Scalded Skin Syndrome

Staphylococcal scalded skin syndrome (SSSS), which has also been called pemphigus neonatorum, is a toxin-mediated blistering condition of the skin that primarily affects infants and young children. Neonatal SSSS and outbreaks in neonatal intensive care units are also known to occur.⁴ The more localized form of the disease is called bullous impetigo; the more widespread counterpart with generalized involvement is called SSSS.

The initiating staphylococcal infection may start with impetigo that is localized, most commonly in the nares, eyes, or umbilicus in neonates. Toxins produced by the Staphylococcus aureus bacteria, exfoliative toxins A and B, are released by the bacteria. These toxins target desmoglein 1, which is a protein vital in epidermal cell-to-cell adhesion.⁵ Infants and young children are most susceptible because of a lack of protective antibodies and immature renal clearance of these toxins. Clinical manifestations are that of initial facial and perioral erythema followed by superficial blisters that may progress rapidly to generalized erythroderma and the appearance of “wrinkled” skin. This is often more noticeable around the mouth and in skin folds.⁴ Affected infants are usually fussy.

Other disorders that may be considered in the differential diagnosis are few, although it may be mistaken for Kawasaki disease, viral exanthema, drug eruption, or toxic epidermal necrolysis. Many of these do not usually occur in the neonatal period.

Often, SSSS is a clinical diagnosis. Any cultures taken from the bullae are expected to be sterile as blisters are directly caused by the toxin and not the bacteria itself. Biopsy can ...