The recent interest in the pharmacology of the skin and the treatment of its diseases has come about for two reasons. The first is a realisation that many aspects of pharmacology can be studied as easily in human skin as in animal models, where they may be more relevant to human physiology and disease. Examples of this are the action of various vasoactive agents and the isolation of mediators of inflammation after UV irradiation and antigen-induced dermatitis. The second reason is the fortuitous realisation that a pharmacological approach to the treatment of skin disease need not always await the full elucidation of aetiology and mechanism. For example, whilst the argument continued un­ resolved as to whether the pilo-sebaceous infection which constitutes acne was due to a blocked duct or to a simple increase in sebum production, 13-cis retinoic acid, was found quite by chance totally to ablate the disease; again, whilst cyclosporin, fresh from its triumphs in organ transplantation, has been found able to suppress the rash of psoriasis, it has resuscitated the debate on aetiology. We are therefore entering a new era in which the pharmacology and clinical pharmacology of skin are being studied as a fascinating new way of exploring questions of human physiology and pharmacology as well as for the development and study of new drugs, use of which will improve disease control and at the same time help to define pathological mechanisms.

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Section A: Methods.- 1 Methods for the Study of Proliferative Rates in Epidermis.- A. Introduction.- B. Impractical Methods.- I. The Fraction Labelled Mitoses Method.- II. The Continuous Labelling Method.- C. Methods Suitable for Short-term Study.- I. Incorporation of Tritiated Thymidine into DNA.- II. Proliferative Indices.- III. The Measurement of Rate Parameters in Epidermis.- D. Conclusion.- References.- 2 Tissue and Fluids: Sampling Techniques.- A. Tissue Sampling.- I. Surgical.- II. Epidermal Samples.- III. Separation of Epidermis from Dermis In Vitro.- 1. Physical Separation.- 2. Enzymic Techniques.- 3. Miscellaneous Agents.- IV. Stratum Corneum Sampling.- V. Corneocyte Sampling.- B. Sampling of Secretions.- I. Sebum.- II. Eccrine Sweat.- III. Apocrine Sweat.- IV. Tissue Fluid.- References.- 3 Measurement of Sweating and Sweat Gland Function.- A. Introduction.- B. Total Body Sweat Loss.- C. Local and Regional Sweat Responses.- I. Qualitative Methods.- II. Quantitative Methods.- D. Induction of Sweating.- I. The Isolated Sweat Gland.- II. Apocrine Sweating.- E. Localisation of Abnormalities Within the Sweat Gland.- References.- 4 Measurement of Human Sebaceous Gland Function.- A. Introduction.- I. Histological Methods.- II. Functional Methods.- B. Measurement of Sebum Excretion Date.- I. Gravimetric Technique.- 1. Materials.- 2. Collection of Sebum.- 3. Extraction and Weighing Lipid.- C. Photometric Technique.- D. Sebum Production Rate.- E. Factors Affecting the Measurement of Sebum Excretion Rate.- F. Measurement of Surface Lipid Composition.- References.- 5 Methods for Assessing the Effect of Drugs on Hair and Nails.- A. Hair Loss.- B. In Vivo Assessment of Hair Growth.- I. Hair Cycle Status.- II. Cell Kinetics.- III. Linear Growth.- IV. Hirsutism and Scalp Hair Density.- V. Elemental Analysis.- C. In Vitro Methods for Detecting the Effect of Drugs.- D. Nail Growth.- E. Penetration of Topical Agents.- F. Radiation Penetration.- G. Wood's Light.- References.- 6 Measurement of Drug Action in the Skin: Sensation.- A. Introduction.- B. Methods for Studying Cutaneous Sensation.- I. Types of Measurement.- 1. Intensive.- 2. Time-Dependent and Spatial Measures.- II. Stimulation Techniques.- 1. Mechanical Stimulation.- 2. Thermal Stimulation.- 3. Chemical Stimulation.- III. Experimental Design.- 1. Design of Experiments on Cutaneous Sensation in Laboratory Animals.- 2. Design of Experiments on Cutaneous Sensation in Humans.- C. Effects of Drugs on Cutaneous Sensation.- I. Drugs that produce Sensation.- 1. Pain-producing Agents.- 2. Substances Producing Itch and Other Non-painful Sensations.- II. Drugs that Modify Sensation.- 1. Local Anaesthetics.- 2. Opioid Analgesics.- 3. Anti-inflammatory Agents.- 4. Adrenaline, Acetylcholine, Capsaicin, Gonadal Hormones.- 5. Anti-pruritic Agents.- D. Final Comments.- References.- 7 The Measurement of Itch.- A. Introduction.- B. Subjective Methods.- I. Threshold.- II. Degree.- C. Objective Methods.- I. Nocturnal Bed Movement.- II. Limb Meters.- III. Relationship of Itch and Scratch.- IV. Short-term Measurement of Itch as Scratch.- References.- 8 Measurement of Skin Thickness, Wealing, Irritant, Immune and Ultraviolet Inflammatory Response in Skin.- A. Measurement of Skin Thickness.- I. The Harpenden Skin Fold Caliper.- II. X-ray.- III. Ultrasound.- IV. Use of Skin Thickness for Lesion Measurement and Response to Treatment.- V. Corticosteroid Atrophy of Skin.- B. Measurement of Different Types of Inflammation and Their Response to Therapy.- I. Measurement of Ultraviolet Erythema.- 1. Minimal Erythema Dose.- 2. Quantification of Erythema.- a) Visual Grading.- b) Colour Comparison Charts.- c) Red-Coloured Optical Filters.- d) Reflectance Spectrophotometry.- II. Weal Reactions.- 1. Dermographic Wealing.- III. Irritant Inflammation.- 1. Transepidermal Water loss.- IV. Immune Reactions.- 1. The Immediate (Type I) Response.- 2. The Delayed (Type IV) Response.- References.- 9 Measurement of Drug Action in Skin: Dermal Connective Tissue.- A. Introduction: Selection of Procedures and Biological Models.- B. Physical Parameters.- C. Morphology.- D. Cell Kinetics.- E. Quantitative Measurements.- I. Collagen.- II. Elastin.- III. Proteoglycans and Glycoproteins.- F. Qualitative Measurements.- I. Collagen.- II. Elastin.- III. Proteoglycans and Glycoproteins.- G. Estimation of Turnover Rate.- I. Collagen.- II. Elastin.- III. Proteoglycans and Glycoproteins.- H. Measurement of Defined Biochemical Parameters.- I. Messenger RNA.- II. Intracellular Post-translational Enzymes.- III. Extracellular Processing Enzymes.- IV. Degradation, Enzymes and Products.- References.- 10 Microbiological Sampling Techniques.- A. Introduction.- B. Surface Distribution.- C. Swabbing Methods.- D. Washing Methods.- E. Follicular Sampling.- F. Miscellaneous Techniques.- G. Comment.- References.- 11 Clinical Trial Methods.- A. The Beginnings.- B. Clinical Trial Principles Applied to Dermatology.- C. The Subjects.- D. Trial Design.- I. Concurrent Comparisons.- 1. Independent Groups.- 2. Related Groups.- a) Cross-over Plans.- b) Matched Pairs.- c) Repeated Measurements.- d) Factorial Plans.- II. Historical Comparisons.- E. Power and Statistical Analysis.- F. Allocation to Treatment.- G. "Intention to Treat".- H. Blindness.- J. Measurements.- I. Measurement Scales.- II. Types of Measurement.- K. The Protocol.- L. The Reasons for Performing Therapeutic Trials.- M. Applying the Results of Trials in Practice.- References.- Section B: Absorption, Metabolism and Toxicity.- 12 The Properties of Skin as a Diffusion Barrier and Route for Absorption.- A. The Location and Nature of the Percutaneous Absorption Barrier.- B. Methods of Measuring Percutaneous Absorption.- I. In Vivo Techniques.- II. In Vitro Techniques.- C. In Vivo - In Vitro Comparisons.- D. Mathematical Derivation of Absorption Parameters.- E. Species Comparisons: Relevance of Animal Data to Humans.- F. Metabolism.- G. Control and Prediction of Absorption.- References.- 13 Skin as a Mode for Systemic Drug Administration.- A. Introduction.- B. Therapeutic Objectives of Transdermal Delivery.- C. Design of a Rate-Controlled Scopolamine System.- D. Controlled Systemic Absorption of Nitroglycerin.- E. New Advances in Transdermal Drug Delivery.- I. Catapres - TTS.- II. Estraderm.- F. The Future.- References.- 14 Drug Metabolism in the Skin.- A. Introduction.- B. Drug Metabolism in General.- C. Drug-Metabolizing Enzymes in Skin.- I. General Remarks.- II. Drug Oxi…