Skin lesions

Cancerous skin lesions of workers exposed to pitch dust undoubtedly support the behef that these lesions are caused by polynuclear aromatic hydrocarbons, although it had not been possible to demonstrate their carcinogenic action in animals more closely related to humans, such as monkeys. 

Nystatin is mainly used to treat vaginal and oral infections and localized skin lesions, including Candida intertrigo and Candida nappy dermatitis. It may also be used as prophylaxis during treatment with antibiotics. 

The toxicity of a substance is its capacity to cause injury once inside the body. The main modes of entry into the body by chemicals in industry are inhalation, ingestion and absorption through the skin. Gases, vapours, mists, dusts, fumes and aerosols can be inhaled and they can also affect the skin, eyes and mucous membranes. Ingestion is rare although possible as a result of poor personal hygiene, subconscious hand-to-mouth contact, or accidents. The skin can be affected directly by contact with the chemicals, even when intact, but its permeability to certain substances also offers a route into the body. Chemicals accorded a skin notation in the list of Occupational Exposure Limits (see Table 5.12) are listed in Table 5.2. Exposure may also arise via skin lesions. 

Total frequencies of environmental illness are difficult to measure. When causes can be identified, however, scientists observe that frequencies of occurrence of a particular illness vary directly with the severity and extent of exposure. Particularly frequent in the workplace are skin lesions from many different causes and pulmonary diseases related to the inhalation of various dusts, such as coal dust (black lung), cotton dust (brown lung), asbestos fibers (asbestosis), and silica dust (silicosis). Environmental agents can also cause biological effects without overt clinical illness (for example, chromosome damage from irradiation). 

Exercise also increases skin circulation and perspiration, which both enhance dermal penetration of compounds into the body. Furthermore, skin lesions, such as wounds and dermatitis, can increase the permeability of the skin to chemicals. Also, exposure of the skin to solvents and removal of skin fat increase dermal penetration of a number of compounds. Compounds penetrate the skin more readily in places where the skin is thin, like the face, hands and scrotum. Increased dermal blood flow due to exercise facilitates the penetration of the skin by chemicals. 

Chemical Acne Many chemical compounds induce skin lesions that are similar to acne. Oils, tar, creosote, and several cosmetic products induce chemical acne. These compounds induce keratinization of the sebaceous glands of the skin, obstruction of the glands, and formation of acne. Chloracne is a specific skin lesion that is induced by chemical compounds that are structurally similar to 2,5,7,8-tet-rachloro dibenzo-p-dioxin (TCDD). Chloracne is slow to heal and difficult to... 

Goldberger and Lillie in 1926 found that rats fed certain nutritionally deficient diets developed dermatitis acrodynia, a skin disorder characterized by edema and lesions of the ears, paws, nose, and tail. Szent-Gyorgyi later found that a factor he had isolated prevented these skin lesions in the rat. He proposed the name vitamin Bg for his factor. Pyridoxine, a form of this vitamin found in plants (and the form of Bg sold commercially), was isolated in 1938 by three research groups working independendy. Pyridoxal and pyridoxamine, the forms that predominate in animals, were... 

Retinoids are needed for cellular differentiation and skin growth. Some retinoids even exert a prophylactic effect on preneoplastic and malignant skin lesions. Fenretlnide (54) is somewhat more selective and less toxic than retinyl acetate (vitamin A acetate) for this purpose. It is synthesized by reaction of all trans-retinoic acid (53), via its acid chloride, with g-aminophe-nol to give ester 54 (13). 

Actinic keratoses were the first skin lesions to be treated topically with all-frans-retinoic acid. In various clinical trials, retinoids have been shown to be active in chemoprevention and treatment or prevention skin malignancies [2]. 

C. Skin lesions should clear within 3 days. 

Q Risk for Infection related to the presence of skin lesions Q Impaired Skin Integrity related to the presence of skin lesions... 

Some patients may experience anxiety about die appearance of certain skin lesions or the symptoms of a specific dermatologic disorder. This may cause a negative body imaga The nurse must allow time for die patient to verbalize concerns or ask questions concerning dierapy. The nurse reassures die patient tiiat die lesions are temporary and will diminish or disappear with treatment (if diat is true). 

TABLE 56-1 Terms Used to Describe Skin Lesions... 

Juvenile dermatomyositis (JDM) is perhaps the most uniform, in terms of clinical and histopathological features, of the whole PM/DM disease complex. Presentation may be before 5 years of age with peak incidence between 8 and 12 years. The disease may remit and recur until well into young adult life. The skin lesions include a facial rash in butterfly distribution across nose and cheeks. Erythematous skin changes are seen over extensor surfaces of joints, especially knees, knuckles and elbows. Muscle involvement is generally evident some time later and takes the form of weakness and stiffness, particularly affecting shoulder and pelvic musculature. Proximal muscles are often worse affected than distal muscles and extensors worse than flexors. In the absence of prompt and effective treatment contractures may occur at elbows, ankles, knees, and hips. Subcutaneous calcification and skin ulceration may be found calcification of deeper-lying connective tissue may be apparent on X-ray. 

Muscle biopsy is usually undertaken to confirm the provisional clinical diagnosis. Because the skin lesions normally precede those in muscle, biopsies of muscle taken early may show little abnormality. Inflammatory foci may be scanty or absent and muscle fiber diameters may be normal. However typical biopsies show discrete foci of inflammatory cells, with a predominance of B-lymphocytes (see Figure 18). These cells are situated in perimysial connective tissue rather than in the en-domysium and are often also perivascular in location. Muscle fiber necrosis occurs in JDM but muscle fibers do not appear to be the primary target of the disordered immune process. Rather, it is the micro vasculature of the muscle which appears to degenerate first and muscle necrosis is preceded by capillary necrosis, detectable at the ultrastructural level. 

Dermal exposure of rats to doses of dimethyltin dichloride at 80 mg/kg body weight produced dermal necrosis with the formation of black scars the same dose of dibutyltin dichloride produced little surface damage to the skin together with subcutaneous oedema. Dioctyltin dichloride produced no skin lesions (Barnes Stoner,... 

Case Studies in Environmental Medicine Taking an Exposure History—The importance of taking an exposure history and how to conduct one are described, and an example of a thorough exposure history is provided. Other case studies of interest include Reproductive and Developmental Hazards Skin Lesions and Environmental Exposures Cholinesterase-Inhibiting Pesticide Toxicity and numerous chemical-specific case studies. 

The diagnosis of PIH is often made by history and clinical presentation. It is characterized by macules and patches of varying shades of hyperpigmentation limited to the sites of inflamed skin lesions. Lesions of the preceding inflammatory process may be present at vari-... 

Ocular eye involvement is common and may precede skin lesions. Ocular symptoms include foreign body sensation, burning or stinging, dryness, itching, ocular photosensitivity, teleangectasia, periorbital edema, chalazia (Fig. 17.8)... 

While all species lost body weight following treatment with 2,3,7,8-TCDD, other signs of toxicity were species dependent. Ascites was seen in mice. Anorexia, dehydration, depression, emaciation, intestinal hemorrhage, and alopecia were seen in dogs. Certain rabbits treated intra-peritoneally with 2,3,7,8-TCDD developed skin lesions typical of those associated with acnegens. 

The most important survival and growth factor for mast cells is the KIT Ugand stem cell factor (SCF) [12], The hypothesis of early studies, that SCF might be elevated in skin lesions associated with mastocytosis [13], however, was not confirmed by later studies on SCF levels in skin and blood, at least for adult patients [14],... 

Florian S, Krauth MX, Simonitsch-Klupp I, et al Indolent systemic mastocytosis with elevated serum tryptase, absence of skin lesions, and recurrent severe anaphylactoid episodes. Int Arch Allergy 43 Immunol 2005 136 273-280. 

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