Amyloidosis Amyloid is a material deposited in the skin and other organs that is eosinophilic, homogeneous, and hyaline in appearance. It represents beta-pleated sheet forms of various host-synthesized molecules processed into this configuration by host cells. Amyloidosis can be classified…
Collagen Many types of collagen have been identified in tissues of vertebrates ( Table 25.1 ). Collagens help form the support structure and scaffolding for many parts of the body, including tissues, blood vessels, and bones. Fibrillar collagens (types I,…
The skin interacts with the endocrine system in many ways. Some of these are discussed in this chapter. Leventhal JS, et al: Skin manifestations of endocrine and neuroendocrine tumors. Semin Oncol 2016; 43: 335. Quatrano NA, et al: Dermatologic manifestations of endocrine…
An inflammatory disorder that is primarily localized in the subcutaneous fat is termed a panniculitis. This group of disorders may be challenging for both the clinician and the dermatopathologist. Clinically, in all forms of panniculitis, lesions present as subcutaneous nodules.…
A nutritional disease is caused either by insufficiency or, less often, by excess of one or more dietary essentials. Nutritional deficiencies are particularly common in developing countries but can also occur due to fad diets or restrictive eating practices in…
In noninherited chronic blistering (vesicular or bullous) dermatoses, the cause of blistering is usually an autoimmune reaction, and the location where antibodies bind determines the clinical, histologic, and immunofluorescent pattern. A thorough understanding of the basement membrane zone (BMZ) structure…
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 reviews parasitic diseases and the major causes of bites and…
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 of viruses only) an outermost membrane or envelope. The capsid…
Syphilis Syphilis, also known as lues, is a contagious, sexually transmitted disease caused by the spirochete Treponema pallidum subspecies pallidum. The only known host is the human. The spirochete enters through the skin or mucous membranes, where the primary manifestations…
Epidemiology The World Health Organization (WHO) has committed itself to eliminating Hansen disease as a public health problem, but the disease remains endemic in certain regions, with 95% of cases reported from 16 countries. Brazil, India, and Indonesia account for…