Fungi are a group of simple plants that lack flowers, leaves, and chlorophyll and get their nourishment from dead or living organic matter, thus depending on plants, animals, and humans for their existence. Fungal infections that affect humans may be…
Several viral and bacterial illnesses may be accompanied by localized or generalized skin eruptions called exanthems . These eruptions may be the first manifestation of a disorder and often are the reason for parents and patients to pursue medical evaluation.…
Viruses are ultramicroscopic organisms that grow only within living cells. The antigenic material responsible for viral immunologic reactions is present in the outer protein membrane (capsid) of the virus. The nucleoprotein core is composed of either deoxyribonucleic acid (DNA) or…
The normal skin of healthy infants and children is resistant to invasion by most bacteria because the cutaneous surface provides a dry mechanical barrier from which contaminating organisms are constantly removed by desquamation. Under normal conditions the skin is sterile…
Blisters or bullae are round or irregularly shaped lesions of the skin or mucous membranes that result from the accumulation of fluid between the cells of the epidermis and sometimes between the epidermis and dermis. The term bullae refers to…
Classification of vascular lesions Vascular birthmarks, or congenital vascular anomalies, are common lesions that may present in a variety of fashions. There has traditionally been a significant amount of confusion regarding the nomenclature of these lesions, and the term hemangioma…
Although chiefly of cosmetic significance, disorders of pigmentation are among the most conspicuous and thus can have profound psychosocial implications for pediatric patients. The most important pigments in skin are melanin, reduced and oxygenated hemoglobin, and carotene. Melanin is a…
The histiocytoses are a broad group of disorders characterized by an abnormal proliferation of the histiocyte, a type of progenitor cell in the bone marrow ( Box 10.1 ). Some clinically relevant types of histiocytes include the Langerhans cell, the…
Because of the increasing public awareness and incidence of skin cancer, physicians are often consulted regarding tumors of the skin. In children, the vast majority of cutaneous tumors are benign, and their importance lies predominantly in the cosmetic defect they…
Disorders of the sebaceous glands Acne vulgaris Acne vulgaris is the most common skin problem in the United States, affecting nearly 80% to 85% of individuals at some point between 11 and 30 years of age. , Although not a…