Scaliness, of the skin

Hirsutism Ichthyosis Abnormal, heavy hairiness A disease characterized by dryness, roughness, and scaliness of the skin caused by hypertrophy of the stratum comeum... 

Chapter 8 Ichthyosis — An Inborn Dryness and Scaliness of the Skin Anders Vahlquist 83... 

Advanced deficiency of vitamin A gives rise to dryness and scaliness of the skin, accompanied by a tendency to infection. Characteristic lesions of the human skin caused by vitamin A deficiency usually ixreur in sexually matuie persons between the ages of 16 and 30 and not in infants. These lesions appear llrsl on the anterolateral surface of the thigh and the posterolateral portion of the upper foreamis and later spread to adjacent areas nf the skin. The le.sions consist of pigmented papules, up to 5 mm in diameter, at the. site of the hair fnllicles. 

A deficiency wherein hyperkeratinization of epidermis and other epithelia occurs. The other metabolic defect is that encountered in Refsum s disease, an inherited neurological disorder biochemically characterized by accumulation of phytanic acid due to failure of tissue hydroxylases to initiate its degradation by a-hydroxylation. In this disease dry hyperkeratotic scaliness of the skin appears in variable degrees, reported to be at times sufficiently extreme to mimic ichthyosis. As in the ichthyoses, hyperkeratinization of other epithelia does not occur. 

At about 32 years of age she started developing weakness in the legs which advanced inexorably to involve the arms and rendered her bedridden for the last five months of her life. Her visual acuity progressively deteriorated during her last 6 years and scaliness of the skin became prominent during the last year of her life. She died suddenly 5 weeks after admission with a presumptive diagnosis of bronchopneumonia. 

The most frequent skin disorder, which affects about 2% of the world s population is psoriasis. The thickened, scaly patches can cover much of the skin and become disabling. The inflammation and excessive epidermal growth are usually a T-cell mediated immunologic response to antigenic stimuli.P u v However, there is a hereditary form.31 Other common skin disorders include actinic keratosis induced by light and cancer. 

Clofazimine is effective against Mycobacterium leprae and is used primarily as an adjunct in the treatment of leprosy. During clofazimine therapy, many patients experience problems with red to brownish-black discoloration of the skin. Although this discoloration is reversible, it may take several months to years before skin color returns to normal. Other adverse effects include abdominal pain, nausea, vomiting, and rough, scaly skin. 

Exposure of the skin to C5-C8 liquids causes dermatitis. This is the most common toxicological occupational problem associated with the use of hydrocarbon liquids in the workplace, and is a consequence of the dissolution of the fat portions of the skin. In addition to becoming inflamed, the skin becomes dry and scaly. 

Biotin deficiency and the functional deficiency associated with lack of holo-carboxylase synthetase (Section 11.2.2.1), or biotinidase (Section 11.2.3.1), causes alopecia (hair loss) and a scaly erythematous dermatitis, especially around the body orifices. The dermatitis is similar to that seen in zinc and essential fatty acid deficiency and is commonly associated with Candida albicans infection. Histology of the skin shows an absence of sebaceous glands and atrophy of the hair follicles. The dermatitis is because of impaired metabolism of polyunsaturated fatty acids as a result of low activity of acetyl CoA carboxylase (Section 11.2.1.1). In biotin-deficient experimental animals, provision of supplements of long-chain 6 polyunsaturated fatty acids prevents the development of skin lesions (Mock et al., 1988a, 1988b Mock, 1991). 

Scaly, resembling the skin of a serpent, dyed grey by subterranean vapour. Silver-coloured Pyrites ... 

It is a yellow, oily substance, which occurs in nature in butter fat and fish oils. Lack of Vitamin A in the diet causes a scaly condition of the eyes, and similar abnormality of the skin in general, together with a decreased resistance to infection of the eyes and skin. In addition there occurs a decreased ability to see at night, called night-blindness. There... 

B2 (riboflavin) Treats scaly dermatitis, cracked comers of the mouth, inflammation of the skin and tongue, and dermatologic problems... 

Mycotic infections of the skin have a classic appearance that consists of a central clearing surrounded by an advancing red, scaly, elevated border." Infections of the nail can appear chalky and dull yellow or white and become brittle and crumbly. 

Psoriasis is a chronic, inflammatory and hyperprolifera-tive disease of the skin, scalp, nails, and joints, affecting 1 to 2% of the U.S. population. It is found worldwide its frequency varies from 0 to 3% among different ethnic groups. Most of its variable clinical presentations eventuate into erythematous, scaly plaques with or without nail disease and arthritis. Susceptibility to psoriasis is umnistakably heritable, but the phenotype is controlled by multiple genes as well as enviromnental factors. Trauma, stress, and infections are important determinants of disease onset and severity. At the cellular level, psoriasis is characterized by markedly increased epidermal proliferation and incomplete differentiation elongation, dilatation, and leakiness of the superficial plexus of dermal capillaries and a mixed inflammatory and immune cell infiltrate of the epidermis and papillary dermis. A multitude of plausible pathomechanisms... 

Depressed appetite, dull, listless appearance, excessive tears, scaliness and sloughing of the skin, reduced egg production, egg size and hatchability (McDowell 1992)... 

Dermatitis is an inflammation caused by defatting of the skin or by contact with an irritating or sensitizing substance. Exposure to solvents often removes oils that keep the skin soft and pliable. Without the oil, the skin is dry, scaly, and tends to crack easily. Such skin has poor resistance to bacterial infections and heals slowly when injured. A primary skin irritant causes dermatitis almost immediately by direct action on the skin. After a while, a person may become sensitized to a chemical. A sensitizer may not cause injury immediately, but will produce susceptibility to a second attack or to other substances. Where sensitivity or allergy dermatitis exists and the skin is affected even by small amounts of the chemical, the affected worker should not be allowed in areas where the chemical is used. 

In 1930, linoleic cis, cis-9,12-octadecadienoic) acid was shown to be effective in preventing the development of certain conditions in rats given diets almost devoid of fat. These animals showed a scaly appearance of the skin and suboptimal performance in growth, reproduction and lactation eventually they died as a result of the deficient diet. More recent work has demonstrated a wide range of symptoms in a variety of animals, including some in human beings under certain circumstances (Table 3.3). 

By feeding a diet composed of 16% casein, approximately 4% salts and vitamins and the remainder sucrose. Burr and Burr were able to induce a dietary deficiency syndrome which they later traced to the absence of linoleic acid. The principal deficiency symptoms were a diminished growth rate and a scaly dermatitis seen principally on the feet and tail. An example of a fat deficient rat is shown in Figure 1. Most of the organs of the body are affected by the deficiency and aberrations in structure or function of many tissues have been observed. Reproduction is impaired, the liver becomes fatty., kidney function is impaired, the electrocardiogram is abnormal, and the permeability of the skin toward water is much increased- This leads to evaporative loss of water and of heat from the body accounting for an increased food consumption and a diminished caloric efficiency. 

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