Dermatoses Resulting from Physical Factors
This chapter catalogues many examples of how the skin reacts to the external environment from which it protects the body. Exposure to physical factors such as heat, cold, moisture, ultraviolet…
Pruritus and Neurocutaneous Diseases
Pruritus often produces distinctive skin lesions, characterized by angulated borders. Endogenous diseases (in common parlance, an “inside job”) tend to produce lesions that are rounded in character, whereas exogenous caustic…
Cutaneous Signs and Diagnosis
The astute clinician uses the appearance of the eruption and its accompanying symptoms to arrive at an accurate diagnosis. A symptom, such as itch or pain, is something that the…
Structure and Function
The diagnosis of skin disease is based on color, morphology, and distribution of cutaneous lesions. The structure of the skin and associated appendages relates directly to these characteristics. Folliculitis presents…
Dermal and Subcutaneous Tumors
In this chapter proliferations derived from vascular endothelial cells, fibroblasts, myofibroblasts, smooth muscle cells, Schwann cells, and lipocytes are reviewed. Also discussed are several neoplasms of cells invading or aberrantly…
Epidermal Nevi, Neoplasms, and Cysts
Epidermal Nevi Epidermal nevi are hamartomatous growths of the epidermis that are present at birth in about half of patients or develop early in childhood. The term epidermal nevus includes…
Viral Diseases
Viruses are obligatory intracellular parasites. The structural components of a viral particle (virion) consist of a central core of nucleic acid, a protective protein coat (capsid), and (in certain groups…
Genodermatoses and Congenital Anomalies
The genetic basis for common diseases such as atopic dermatitis and psoriasis, in addition to rare diseases, has been partially elucidated. Some genetic disorders are explained by mutations in a…
Parasitic Infestations, Stings, and Bites
The major groups of animals responsible for bites, stings, and parasitic infections in humans belong to the phyla Arthropoda, Chordata, Cnidaria (formerly Coelenterata), Nemathelminthes, Platyhelminthes, Annelida, and Protozoa. This chapter…
Diseases of the Skin Appendages
Diseases of the Hair Normal human hairs can be classified according to cyclic phases of growth. Anagen hairs are growing hairs; catagen hairs are those undergoing transition from the growing…
