Neonatal skin The skin of the infant differs from that of an adult in that it is thinner (40% to 60%), is less hairy, and has a weaker attachment between the epidermis and dermis. In addition, the body surface area–to–weight ratio of an infant is up to five times that of an adult. The infant is therefore at a significantly increased risk for skin injury, percutaneous…
Accurate diagnosis of cutaneous disease in infants and children is a systematic process that requires careful inspection, evaluation, and some knowledge of dermatologic terminology and morphology to develop a prioritized differential diagnosis. The manifestations of skin disorders in infants and young children often vary from those of the same diseases in older children and adults. The diagnosis may be obscured, for example, by different reaction patterns…
Addison's Disease Addison's disease (chronic primary adrenocortical insufficiency) occurs when the adrenal gland has lost most of its functional capacity. Addison's disease can be caused by many different disease states that inhibit the functioning of the adrenal gland. The adrenal gland has a massive reserve capacity, and clinical manifestations of chronic adrenal insufficiency are not seen until the bilateral glands have lost at least 90% of…
Beriberi Beriberi is a nutritional deficiency state that is caused directly by a lack of thiamine (vitamin B 1 ) in one's diet or by a lack of proper absorption of the vitamin. A rare form of acquired thiamine deficiency occurs after the ingestion of thiaminase, an enzyme that cleaves thiamine into a nonfunctional state. These cases are exceedingly rare and are considered to occur after…
Alopecia Areata Alopecia areata is an autoimmune disease that causes discrete circular or oval areas of nonscarring alopecia. This form of alopecia has several clinical variants, including alopecia totalis, alopecia universalis, and an ophiasis pattern. Therapy is often difficult. The disease can have profound psychological impact, especially in young patients. It is critical to address this issue, because the effects on the patient's psychological well-being are…
Actinomycosis Many species of the bacterial genus Actinomyces are able to cause disease in humans. The infection tends to run a chronic course that leads to suppurative granulomatous abscesses in the skin. The diagnosis may be suspected if there is clinical evidence of painful draining of suppurative material and histological evidence of granuloma formation. The exact diagnosis is based on tissue culture or culture of the…
Basement Membrane Zone, Hemidesmosome, and Desmosome Basement Membrane Zone The basement membrane zone (BMZ) of the epidermis is a beautiful and complex structure and a marvel of biological engineering. The zone acts to attach the overlying epidermis to the underlying stromal tissue, in this case the papillary dermis, which is made predominantly of collagen bundles. A plethora of unique and specialized proteins play critical roles in…
Acanthosis Nigricans Acanthosis nigricans is a commonly encountered skin dermatosis that can be seen in various clinical scenarios. It is overwhelmingly associated with obesity but can occur secondary to medications, endocrine disorders such as the HAIR-AN syndrome ( h yper a ndrogenism, i nsulin r esistance, and a canthosis n igricans), diabetes, and internal malignancies. This last type is clinically distinctive and manifests in a unique…
Adnexal Carcinoma Adnexal carcinomas are a diverse group of malignant skin tumors that are derived from the various components of the skin appendageal structures. These tumors are extremely rare and comprise well less than 1% of all skin cancers diagnosed annually. They are difficult to diagnosis clinically because they can all mimic the more common types of skin cancer, particularly basal cell carcinoma and squamous cell…
Acrochordon Acrochordons are better known by their common name of skin tag or fibroepithelial polyp. They are found universally throughout humankind. Probably every adult has at least one skin tag located somewhere across the surface of his or her skin. Except for a few loose associations with certain syndromes, skin tags have no clinical importance and are often ignored. Clinical Findings: Skin tags can be found…
Introduction Bacterial skin infections in neonates and infants can present differently from those in older children, based on several factors: (1) the nature of the pathogen; (2) the developmental stage of the infant when infection is acquired: early (first or second trimester) versus late (third trimester) in gestation and early (first few days) versus late (2–8 weeks) postnatal life; and (3) the manner in which inoculation…
Embryology of the Skin The human skin develops from two special embryonic tissues, the ectoderm and the mesoderm. Epidermal tissue is derived from the embryonic ectoderm. The dermis and subcutaneous tissue are derived from the embryonic mesoderm. The developmental interactions between mesoderm and ectoderm ultimately determine the nature of human skin. Interestingly, neural tissue and epidermal tissue are both derived from the ectoderm. It is believed…
Inherited blistering diseases Epidermolysis bullosa Epidermolysis bullosa (EB) is a family of rare, inherited disorders characterized by fragility of the skin and sometimes the mucosa in response to minor mechanical trauma. EB is caused by mutations in at least 14 genes that encode proteins of the basement membrane zone (BMZ) of the skin ( Fig. 11.1 ). BMZ proteins are structural molecules involved in the adhesion…
Introduction Vesiculopustular and bullous disorders are common in the neonatal period and the first years of life. Accurate and prompt diagnosis is essential because some conditions that present with blisters and pustules are truly life-threatening. In contrast, many others are innocuous and self-limited; misdiagnosis of a more serious condition can lead to iatrogenic complications, unnecessary expense, and parental anguish. The causes of blisters and pustules in…
Introduction Developmental abnormalities of the skin are a diverse group of anomalies representing errors in morphogenesis. By definition, they are present at birth, although some are not evident in the neonatal period, but most present during infancy. They vary in severity from the inconsequential to the serious and, in some instances, represent a marker for significant extracutaneous anomalies. Supernumerary mammary tissue Accessory mammary tissue (supernumerary nipples,…
Introduction A variety of untoward events may befall the developing infant while in utero or postpartum. Some of these perinatal problems are inherent in the birth process. Others are related to technologic advances that have become standard obstetric and nursery practice. Although these diagnostic and therapeutic procedures have reduced morbidity and mortality, some also pose a significant risk for iatrogenic complications. Sequelae of iatrogenic complications can…
Introduction Transient benign cutaneous lesions in the newborn are important to recognize. Not only can parents be reassured, but costly, unnecessary and erroneous evaluations and treatment of presumed serious diseases can be prevented. This chapter discusses the most common transient benign conditions seen in neonates. Table 7.1 summarizes 15 studies of the incidences of transient benign cutaneous lesions. In some instances, racial and ethnic background may…
Introduction Diagnostic and therapeutic procedures are a standard part of the evaluation and management of dermatologic conditions in neonates and infants. Performing procedures on younger children can be technically challenging, and requires knowledge of differences in approach and other special considerations due to the child's young age. This chapter discusses the most common of these diagnostic and therapeutic procedures. Diagnostic procedures Bacterial culture Bacterial culture is…
Introduction The skin of the neonate has a defective skin barrier relative to an older child. The neonate is extremely vulnerable to damage by environmental agents such as harsh detergents, some topical oils and other irritant chemicals. These agents can interact with genetic tendencies such as FLG gene variants and lead to the development of compromised barrier function, and may contribute to the development of atopic…
Introduction The premature infant assumes the challenge of postnatal life, despite the immaturity of essential functions. Skin functions are primarily protective, and immaturity of the skin contributes to the vulnerability of the preterm infant. The main function of the skin is to provide a permeability barrier that both protects the aqueous interior of the infant from desiccation in the xeric atmosphere and prevents massive influx of…