Poisoning with Nicotine Patches

To evaluate potential adverse effects from inadvertent exposure, three marketed TD nicotine products Nicoderm (drug reservoir and rate-controlling membrane) Nico-tinell (nicotine solution dispersed in cotton gauze between layers of adhesive) and Niconil (nicotine in gel matrix), were administered topically and orally to dogs (133). Topical nicotine doses were 1-2 mg kg 24 h-1 for all products, with plasma con centrations 43 ng mL, or less. Of 12 topical exposures (with Nicotinell and Niconil) 2...

Viral Infections

Herpes simplex type I commonly causes herpetic lesions on the face and oropharynx whereas herpes simplex type 2 affects the genitalia. Following a primary infection, the virus may become latent within nerve ganglia and recurrent episodes may occur periodically. In children, primary herpes simplex type 1 infection presents as an acute gingivostomatitis with vesicles (which may subsequently ulcerate) scattered on the lips and buccal mucosa. The infection is accompanied by malaise, headache, and...

Acne A Introduction

Acne is one of the most common and distressing of skin diseases commonly present during adolescence and usually (but not always) resolves in early adult life. Seventy percent of the population develop acne, but only a relatively small proportion seek medical attention. Several variants of acne are recognized, including infantile acne, which occurs on the face during the first few months and usually settles spontaneously, and occupational acne, resulting from exposure to oil, coal tar,...

References

Nevill AM. (1994) The need to scale for differences in body size and mass and explanation of Klieber's 0.75 mass exponent. Am Physiol Soc pp 2870-2873. 2. Lavker RM, Sun T. (1982) Heterogeneity in epidermal basal keratinocytes morphological and functional correlations. Science 215 1239-1241. 3. Borradori L, Sonnenberg A. (1999) Structure and function of hemidesmosomes more than simple adhesion complexes. J Invest Dermatol 112 411-418. 4. Sawamura D, Li K, Chu M-L, Uitto J. (1991) Human bullous...

Smoking Cessation

Data on efficacy, safety, and pharmacoeconomics of transdermal (TD) nicotine therapy for smoking cessation up to 1994 were reviewed (86). TD nicotine more than doubled success rates of smoking cessation in motivated subjects smoking 10-15, or more, cigarettes a day. Application site reactions (erythema or burning < 16 , transient itch < 50 ) caused discontinuation in 10 , or fewer of subjects. Sleep disturbance due to nocturnal nicotine absorption occurred in less than 13 of subjects....

Hair Follicles and Sweat Ducts

Hair Ostium

Possible routes of penetration through hair follicles could involve the hair fiber itself, through the outer root sheath of the hair into the viable cells of the follicle, or through the air-filled canal and into the sebaceous gland. In addition, the release of sebum by the sebaceous glands may provide a lipoidal pathway that may influence absorption by this route (228). The route for the sweat duct may involve diffusion through either the lumen or walls to below the epidermis and through the...

Infection Of The Skin

This disease is caused by Pityrosporum orbiculare, a gram-positive yeast-like microorganism that is usually a skin commensal. In some individuals, the organism can become pathogenic. Pityrosporum versicolor often affects young adults, causing brown scaly macules on the trunk and sometimes on the limbs. Carboxylic acids released by the organisms inhibit melanogenesis and thus the affected areas may appear relatively pale following exposure to sunlight. The infection may be demonstrated by...

Species Variation in Skin Structure

Most species in which skin permeability has been investigated are mammals, and their skin is macroscopically separated into three layers, the stratum corneum, the viable epidermis, and the dermis. The most important considerations in terms of barrier function are differences in the sebum, SC, and follicles. Small laboratory animals, such as rats, mice, and rabbits, lack sweat glands, but have more hair follicles than human skin. For example, guinea pig skin contains about 4,000-5,000 follicles...

Seborrheic Eczema

In infants, seborrheic eczema may present as greasy adherent scale on the scalp (cradle cap). Seborrheic eczema in adults principally affects the greasier areas of the body, including the scalp, eyebrows, eyelids, nasal-labial areas, and chin. In young men, it may also affect the presternal area and upper back and, in the elderly, may involve the flexures and may become generalized. Individuals who are immunosup-pressed (including those with human immunodeficiency virus HIV) are more prone to...

References Of Mussen

Requests for proposals for enforceable consent agreements dermal absorption rate testing of eighty OHSA chemicals solicitation of interested parties text of protocol. April 3, 61 65 1996. 2. Walker JD, Whittaker C, McDougal JN. Role of the TSCA interagency testing committee in meeting the U.S. government data needs designating chemicals for percutaneous absorption rate testing. In Marzulli FN, Maibach HI, eds. Dermatotoxicology, 5th ed. Washington, DC Taylor amp Francis, pp...

Info

Effect of hydration upon the fluidity of intercellular membranes of stratum corneum an EPR study. Biochim Biophys Acta 1237 6-15, 1995. Alonso A, Meirelles NC, Yushmanov VE, Tabak M. Water increases the fluidity of intercellular membranes of stratum corneum correlation with water permeability, elastic, and electrical resistance properties. J Invest Dermatol 106 1058-63, 1996. Wiedmann TS. Influence of hydration on epidermal tissue. J Pharm Sci 77 1037-1041,...

Transappendageal Transport

The role of appendages in skin transport has been controversial and remains so. The earliest evidence to support the existence of the transfollicular route of transdermal Figure 32 A Correlation between in vivo and in vitro transdermal drug flux each datapoint represents a different drug, dashed line indicates perfect correlation between in vivo and in vitro transdermal drug flux B fraction of total concentration of topically applied methylsalicylate determined in microdialysate or in vitro...

Solar Keratoses

Solar actinic keratoses present as scaling hyperkeratotic plaques or papules on skin exposed to light. They are most commonly seen on elderly subjects with fair skin who have had high levels of ultraviolet exposure over many years. They may be associated with other signs of photodamage such as yellowing, coarsening, and wrinkling of the skin. Individuals with large numbers of solar keratoses are at increased risk of developing nonmelanoma skin cancer. Histologically, the lesions show epidermal...

Introduction

Enzyme Regulation Stomach

The skin is the largest organ of the body, accounting for more than 10 of body mass, and the one that enables the body to interact most intimately with its environment. Figure 1 shows a diagrammatic illustration of the skin. In essence, the skin consists of four layers the stratum corneum nonviable epidermis , the remaining layers of the epidermis viable epidermis , dermis, and subcutaneous tissues. There are also several associated appendages hair follicles, sweat ducts, apocrine glands, and...

Treatment of Scalp Psoriasis

Scalp psoriasis, similar to psoriasis elsewhere, will respond to a similar range of topical therapy although the presence of hair makes treatment more difficult. Application is messy. For thick plaques on the scalp topical therapies include oil of cade, ung. cocois,'' and combinations of coal tar and salicylic acid such as 6 coal tar and 3 salicylic acid , all of which are effective at removing scale and settling inflammation. These preparations may be applied to the scalp and left on overnight...

Atopic Eczema Dermatitis

The etiology of atopic eczema is unknown. Patients have increased levels of serum IgE and some have precipitating antibodies to environmental allergens, including foods and inhaled materials. Many patients will have a positive response to intracutaneous challenge with pollen, house dust mite, cat fur, and fish antigens. However, the significance of these positive reactions is unclear. Patients with atopic eczema have reduced numbers of circulating T-suppressor cells which are responsible for...

Biochemical Abnormalities

There are a large number of diseases that can affect epidermal barrier function, and it is beyond the scope of this chapter to consider any of these in great depth. Some of the diseases affect the formation of the corneocyte ''broken brick syndrome'' whereas other affect the intercellular lipid ''weak mortar syndrome'' . For instance, Nemes and Steinhardt 66 refer to more than ten different diseases involving genes that encode keratin intermediate filaments, including Unna-Thost disease and...

Chemical Damage

When the stratum corneum is perturbed, several localized biochemical events occur that result in rapid reconstitution of barrier function 64,129-137 . Thus, in extreme cases of stratum corneum damage, such as acetone-induced delipidation 129-131 or tape-stripping 137 , there appears to be a biphasic pattern of recovery a rapid phase of repair, followed by a slower phase of normalization. The initial rapid phase of barrier recovery involves the expeditious secretion of preformed lamellar bodies...