Recent and rapid advances in genetics have had an impact on our understanding of skin diseases. The Human Genome Project has now mapped all human genes, of which there are about 35 000. Whilst the original Mendelian concept of single…
Inflammatory responses are central to biological homeostasis. Inflammation is mediated by molecular signalling between resident skin cells and specialized immunological cells which results in specific cellular interactions, or by release of soluble mediators. In the skin, strong inflammatory reactions are…
Keratins The important molecules synthesized by the skin include keratin, melanin, collagen and glycosaminoglycans (GAGs). Keratins are high-molecular-weight polypeptide chains produced by keratinocytes ( Fig. 4.1 ). They are the major constituents of the stratum corneum, hair and nails. The…
The skin is a metabolically active organ with vital functions ( Box 3.1 ), including the protection and homeostasis of the body. Box 3.1 Functions of skin Presents barrier to physical agents Protects against mechanical injury Antimicrobial peptides have a…
Hair Hairs are found over the entire surface of the skin, with the exception of the glabrous skin of the palms, soles, glans penis and vulval introitus. The density of follicles is greatest on the face. Embryologically, the hair follicle…
Key features ▪ The skin is one of the most common targets for adverse drug reactions ▪ To determine the cause of the eruption, a logical approach based on clinical characteristics, chronologic factors, and a literature search is required ▪…
Introduction The skin is one of the largest organs in the body, having a surface area of 1.8 m 2 and making up about 16% of body weight. It has many functions, the most important of which is as a…
Erythema Multiforme Synonym ▪ Erythema multiforme minor – erythema multiforme von Hebra Key features ▪ A self-limited but potentially recurrent disease ▪ Abrupt onset of papular “target” lesions, with the vast majority of lesions appearing within 24 hours ▪ Two…
Introduction Erythema represents a change in the color of the skin that is due to the dilation of blood vessels, especially those in the papillary and reticular dermis. The color, which is blanchable, can vary from pink to dark red…
Synonyms ▪ Wheals – hives, nettle rash ▪ Angioedema – Quincke edema, angioneurotic edema Key features ▪ Urticaria is characterized by transient skin or mucosal swellings due to plasma leakage. Superficial dermal swellings are wheals, and deep swellings of the…