Handbook of Dermatology

A Practical Manual

Margaret W. Mann, Daniel L. Popkin, Margaret W. Mann, Daniel L. Popkin

• Publisher: Wiley-Blackwell
• Year: 2019
• Print ISBN: 9781118408544
• eBook ISBN: 9781118408520
• Edition: 2
• Topic: Medicine
• Subtopic: Dermatology

The Handbook of Dermatology consolidates the essential information required for best-practice patient care into one pocket-sized volume. This indispensable reference guide enables practicing and prospective dermatologists to easily look up information on a wide range of dermatological diseases and quickly access the algorithms, protocols, guidelines, and staging and scoring systems that are vital to both clinical practice and exam success. Written and edited by former residents and attending physicians, the Handbook contains up-to-date information on general dermatology, surgery, and therapeutics.

Part 1
General Dermatology

COMMON WORK‐UPS, SIGNS, AND MANAGEMENT

Dermatologic Differential Algorithm

Courtesy of Dr. Neel Patel

1. Is it a rash or growth?
2. If it is a rash, is it mainly epidermal, dermal, subcutaneous, or a combination?
3. If the rash is epidermal or a combination, try to define the characteristics of the rash. Is it mainly papulosquamous? Papulopustular? Blistering?
   After defining the characteristics, then think about causes of that type of rash: CITES MVA PITA:
   Congenital, Infections, Tumor, Endocrinologic, Solar related, Metabolic, Vascular, Allergic, Psychiatric, Latrogenic, Trauma, Autoimmune. When generating the differential, take the history and location of the rash into account.
4. If the rash is dermal or subcutaneous, then think of cells and substances that infiltrate and associated diseases (histiocytes, lymphocytes, mast cells, neutrophils, metastatic tumors, mucin, amyloid, immunoglobulin, etc.).
5. If the lesion is a growth, is it benign or malignant in appearance? Think of cells in the skin and their associated diseases (keratinocytes, fibroblasts, neurons, adipocytes, melanocytes, histiocytes, pericytes, endothelial cells, smooth muscle cells, follicular cells, sebocytes, eccrine cells, apocrine cells, etc.).

Direct Immunofluorescence (Dif)

Diseases	Where to biopsy
LE, MCTD, PCT, LP, vasculitis	Erythematous border of active lesion/involved skin (avoid old lesions, facial lesions, and ulcers)
Pemphigus group, pemphigoid group, linear IgA	Erythematous perilesional skin (avoid bullae, ulcers, and erosions)
DH	Normal‐looking perilesional skin (0.5–1 cm away)
Lupus band	Uninvolved, non‐photoexposed skin (buttock)

Source: http://www.mayoclinic.org/dermatology‐rst/immunofaqs.html

False positive/negative DIFs:

False negative in BP: (i) low yield of biopsy on distal extremity (esp. legs) (controversial) and (ii) predominantly IgG4 subclass of auto‐antibody (poorly recognized on DIF)

False positive in LE: chronically sun‐exposed skin of young adults

To increase DIF yield: transport in saline (reduces dermal background) – cannot do DIF on formalin‐fixed specimen

Workup Quick Reference Orders (guided by clinical presentation)

Acanthosis nigricans

CBC/CMP, lipid panel, HgA1C, TSH, CEA, L...

Table of contents

• Cover
• Table of Contents
• Preface
• Acknowledgments
• Part 1: General Dermatology
• Part 2: Surgical and Cosmetic Dermatology
• Part 3: Drugs and Therapies
• Index
• Supplementary Images
• End User License Agreement