© 2002–2006 Ardor Scribendi, Ltd. All rights reserved.

How to Use This Book

For those who are new to diagnosis histopathologic of inflammatory diseases of the skin, and even for those who are seasoned practitioners, we urge that each chapter in this volume be read sequentially before attempting to apply the algorithmic method predicated on pattern analysis to the nearly 140 disorders, each addressed in a subchapter that appears on the Web, lodged either in Chapter 10 (Inflammatory diseases) or Chapter 11 (Simulators of inflammatory diseases). The nine chapters contained in this book were crafted with the purpose in mind of introducing the subject, comprehensively, that is announced in the title of it. If a student is not conversant with embryologic, histologic, and anatomic aspects of skin, with the differences, conceptual, among inflammation, inflammatory disease, and cells that mediate inflammatory diseases, and with definitions of terms essential in the language of inflammatory disease, as well as with knowledge of biopsy proper for sampling inflammatory diseases of the skin, a solid basis will not have been established for utilizing the method advised by us for reaching, by conventional microscopy, a diagnosis with specificity.

Once a histopathologist is confronted with sections of tissue within which are findings of an inflammatory disease in the skin and/or subcutaneous fat, and then embarks on an effort to diagnose that particular disease with precision according to the method that we advocate, the following procedure, stepwise, is advised:

1. Identify the particular pattern (one of eight, seven pertinent to skin and one to subcutaneous fat) described in detail in Chapter 5.
2. Refer to the algorithm in Chapter 5 that is relevant to the particular pattern.
3. Follow the lead provided by the algorithm to the one disease that seems to be the most likely diagnosis.
4. Look up the specific disease listed alphabetically in Chapters 10 and 11 on Derm101.com or search the term online in the section devoted to Inflammatory Disease. In the subchapters of those two chapters, criteria for diagnosis histopathologic with exactness are provided. Photomicrographs, which appear at the end of the "Comment" section of each subchapter, should be scoured as a routine; the crucial attributes of them also are presented, pictorially and in terse legends, in algorithmic fashion thus: From left to right across a page are three slots of uniform size; the first contains a photomicrograph "shot" at low magnification, beneath which is stated the basic pattern; between the first and second slot is a plus sign (+); the second slot accommodates a photomicrograph taken at high magnification, beneath which is stated the elements that must be added to the basic pattern if a diagnosis with specificity is to be attained; between the second and third slots is an equal sign (=); the third slot encloses the diagnosis, it being framed always in the language of clinical dermatology and it being followed by a statement meant to elucidate the changes in that very section of tissue. In short, the principle that animates this algorithmic method for diagnosis obtains throughout the book, including the legends to photomicrographs in Chapters 10 and 11.
5. Determine whether criteria elaborated on histopathologically and clinically for diagnosis of every disease considered in this work are fulfilled by the particular disease to which the algorithm has led; if not, return to the algorithm and proceed anew in quest of that diagnosis.

We sought in this endeavor to simplify the subject of diagnosis of inflammatory skin diseases utilizing conventional microscopy by placing look-alikes together in the same category, the unifying elements being changes histopathologic. As an example, acrodermatitis enteropathica, necrolytic migratory erythema, pellagra, Hartnup‘s disease, kwashiorkor, and maple syrup disease, although different from one another clinically, are presented together in the same subchapter because they are indistinguishable from one another histopathologically. Those six diseases have in common deficiency of an element essential to health. Not all look-alikes histopathologic, however, have either cause or pathogenesis in common, e.g., bullous impetigo, pemphigus foliaceus, pemphigus erythematosus, fogo selvagem, and staphylococcal scalded skin syndrome.* Those diseases should appear together in the same subchapter and for the same reason, namely, they are indistinguishable from one another at scanning magnification (only bullous impetigo is differentiable at high power by virtue of the presence of bacteria within neutrophils). By grouping diseases together on the basis of findings histopathologic, despite big differences among those diseases in character fundamental, we aim to assist colleagues in organizing their thinking about inflammatory skin diseases in general and in thinking logically in pursuit of diagnosis with specificity.

*Staphylococcal scalded skin syndrome is treated separately for a reason explained in the subchapter devoted to it.

Should a reader seek to inquire about one or more aspects of a particular disease, independent of employing an algorithm for diagnosis of it, there is need only to refer to that malady as it is listed in alphabetical order in Chapter 10 or 11, or by way of the Index that follows Chapter 11 on Derm101.com. All the synonyms for a particular disease can be found at the outset of the subchapter dedicated to it, e.g., all of the designations equivalent for pustular psoriasis, such as acrodermatitis continua, dermatitis repens, impetigo herpetiformis, keratoderma blennorrhagicum, pustular bacterid, and subcorneal pustular dermatosis. Pustular psoriasis, itself, appears in the subchapter given to psoriasis because it represents acceleration inordinately of the psoriatic process. Should a reader wish to gain a global view of inflammatory skin diseases pictorially, the photomicrographs at the end of each category may serve as an atlas.

All the common inflammatory diseases of the skin are addressed in this book. Some diseases, however, are so recondite that we have had no experience with them. Rather than call on the work of other colleagues, no matter how respected, for information about those conditions, we have chosen to avoid consideration of them entirely. In that way, we are able to take responsibility fully for all the statements made in these pages.

Because various neoplastic diseases of the skin, e.g., mycosis fungoides, telangiectasia macularis eruptiva perstans, and histiocytosis X, and even certain aberrations of other kinds, e.g., Darier‘s disease, acroangiodermatitis of Mali, and porokeratosis of Mibelli, may simulate authentic inflammatory diseases of the skin, a clear distinction has been made in that regard in the organization of diseases found on the Web, namely, between true inflammatory diseases in Chapter 10 and noninflammatory simulators of those diseases in Chapter 11. In this way, readers are alerted to possibilities diagnostic beyond inflammatory diseases themselves. It is difficult, however, to decide whether some diseases really are inflammatory truly, e.g., pyogenic granuloma, hypodermatitis sclerodermiformis, nephrogenic fibrosing dermopathy, scleromyxedema, and vitiligo. We have made determinations about each of them in as rational a fashion as possible.

Readers doubtlessly will be frustrated when they are unable to come to a diagnosis with specificity using the method espoused in this book. When that happens, they should take some measure of solace from the fact that we, all too often, have fared no better. Let them be assured, however, that dogged attempts at clinicopathologic correlation introduced in this work for most diseases under consideration (and in "Interactive Quizzes" linked to them) in conjunction with an algorithmic method based on pattern analysis will result in ever-increasing capability for coming to specific, accurate diagnoses histopathologic of inflammatory diseases of the skin and subcutaneous fat.

Frustration also will surface when a particular disease is not discussed in extenso, such as some simulators of inflammatory diseases of the skin, for example, certain leukemias, extramedullary hematopoiesis, angiolymphoid hyperplasia with eosinophilia, lymphoepithelioma-like carcinoma, and, episodically, particular undifferentiated malignant neoplasms metastatic to skin. Such is the beauty of the Web! Soon those diseases, and others that should be addressed in this Arbeit, will appear in Chapter 11!

Last, Chapter 7 in this volume brings the algorithmic method for specific diagnosis of inflammatory skin diseases full circle. In Chapters 5 and 6, observations about distinctive patterns noted at scanning magnification are used to lead histopathologists to specific diagnoses according to a particular algorithmic method. The mode of thought of Chapter 7 is just the reverse, to wit, "nonspecific" findings noted at high magnification serve as the first step in forging an algorithm by which observations made at progressively lower magnifications are added successively, thereby enabling a histopathologist to come, with confidence equally, to diagnosis with specificity. The two systems are complementary; both employ algorithms and both show the way to fulfilling the objective of this enterprise, namely, diagnosis accurately and precisely of cutaneous and subcutaneous inflammatory diseases.

© 2002–2006 Ardor Scribendi, Ltd. All rights reserved.