Dermatology dermatology
Medical Knowledge Self-Assessment Program
Dermatology All New Content, Including 72 Multiple-Choice Questions
150591010
10 AMA PRA Category 1 Credits™ available until July 31, 2015.
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Table of Contents
Approach to the Patient with Dermatologic Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Herpes Zoster . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Warts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Molluscum Contagiosum . . . . . . . . . . . . . . . . . . 31
Therapeutic Principles in Dermatology Topical Corticosteroids . . . . . . . . . . . . . . . . . . . . . . . . . 2 Treatment of Dermatologic Conditions in Pregnancy . . 4
Common Rashes Eczematous Dermatoses . . . . . . . . . . . . . . . . . . . . . . . . 5 Contact Dermatitis . . . . . . . . . . . . . . . . . . . . . . . . 5 Hand Dermatitis . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Xerotic Eczema . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Nummular Dermatitis . . . . . . . . . . . . . . . . . . . . . . 7 Stasis Dermatitis . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Atopic Dermatitis . . . . . . . . . . . . . . . . . . . . . . . . . 8 Papulosquamous Dermatoses . . . . . . . . . . . . . . . . . . . 10 Psoriasis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Lichen Planus . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Pityriasis Rosea . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Seborrheic Dermatitis . . . . . . . . . . . . . . . . . . . . . 14 Drug Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Pigmented Purpuric Dermatoses. . . . . . . . . . . . . . . . . 16 Miliaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Acantholytic Dermatosis (Grover Disease) . . . . . . . . . 17
Acneiform Eruptions Acne. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Rosacea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Hidradenitis Suppurativa. . . . . . . . . . . . . . . . . . . . . . . 22
Common Skin and Nail Infections Bacterial Skin Infections . . . . . . . . . . . . . . . . . . . . . . . 22 Folliculitis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Abscesses/Furuncles/Carbuncles . . . . . . . . . . . . 23 Impetigo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Cellulitis and Erysipelas . . . . . . . . . . . . . . . . . . . . 24 Erythrasma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Keratolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Superficial Fungal Infections . . . . . . . . . . . . . . . . . . . . 26 Tinea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Candidiasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Viral Skin Infections . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Herpes Simplex Virus . . . . . . . . . . . . . . . . . . . . . 27
Stings and Bites Scabies Infestation . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Lice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Bedbugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Spider Bites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Cuts, Scrapes, and Burns Cuts and Scrapes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Burns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Common Neoplasms Basal Cell Carcinoma . . . . . . . . . . . . . . . . . . . . . . . . . 34 Actinic Keratoses and Squamous Cell Carcinoma In Situ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Squamous Cell Carcinoma . . . . . . . . . . . . . . . . . . . . . 36 Keratoacanthoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Malignant Melanoma . . . . . . . . . . . . . . . . . . . . . . . . . 37 Seborrheic Keratoses. . . . . . . . . . . . . . . . . . . . . . . . . . 39 Melanocytic Nevi . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Dysplastic Nevi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Halo Nevi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Sebaceous Hyperplasia . . . . . . . . . . . . . . . . . . . . . . . . 40 Neurofibromas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Acrochordons (Skin Tags). . . . . . . . . . . . . . . . . . . . . . 40 Cherry Hemangiomas . . . . . . . . . . . . . . . . . . . . . . . . 41 Dermatofibromas . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Solar Lentigines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Hypertrophic Scars and Keloids . . . . . . . . . . . . . . . . . 41 Pyogenic Granulomas . . . . . . . . . . . . . . . . . . . . . . . . . 41 Epidermal Inclusion Cysts. . . . . . . . . . . . . . . . . . . . . . 41 Lipomas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Pruritus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Urticaria Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Clinical Manifestations and Diagnosis . . . . . . . . . . . . . 44 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
ix
Recognizing and Diagnosing Autoimmune Bullous Diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Disease Associations . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Scarring Alopecias. . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Traction Alopecia. . . . . . . . . . . . . . . . . . . . . . . . . 66 Central Centrifugal Cicatricial Alopecia . . . . . . . . 66 Lichen Planopilaris. . . . . . . . . . . . . . . . . . . . . . . . 67 Lupus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Cutaneous Manifestations of Internal Disease
Nail Disorders
Rheumatology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Lupus Erythematosus . . . . . . . . . . . . . . . . . . . . . 48 Dermatomyositis . . . . . . . . . . . . . . . . . . . . . . . . . 50 Livedo Reticularis . . . . . . . . . . . . . . . . . . . . . . . . 51 Purpura and Cutaneous Vasculitis . . . . . . . . . . . . 51 Rheumatoid Arthritis. . . . . . . . . . . . . . . . . . . . . . 53 Nephrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Pruritus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Calciphylaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Nephrogenic Systemic Fibrosis . . . . . . . . . . . . . . 54 Cutaneous Malignancies Following Kidney Transplantation . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Pulmonology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Sarcoidosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Erythema Nodosum . . . . . . . . . . . . . . . . . . . . . . 55 Gastroenterology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Inflammatory Bowel Disease . . . . . . . . . . . . . . . . 56 End-Stage Liver Disease . . . . . . . . . . . . . . . . . . . 57 Hematology/Oncology . . . . . . . . . . . . . . . . . . . . . . . 58 Sweet Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . 58 Endocrinology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Diabetes Mellitus. . . . . . . . . . . . . . . . . . . . . . . . . 60 Thyroid Disease. . . . . . . . . . . . . . . . . . . . . . . . . . 61 Infectious Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 HIV Infection . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Psoriatic Nail Changes . . . . . . . . . . . . . . . . . . . . . . . . 67 Lichen Planus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Melanonychia and Subungual Melanoma . . . . . . . . . . 68 Beau Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Median Nail Dystrophy . . . . . . . . . . . . . . . . . . . . . . . 69 Onychomycosis . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Onychogryphosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Autoimmune Bullous Diseases
Disorders of Mucous Membranes Oral Melanotic Macule . . . . . . . . . . . . . . . . . . . . . . . . 70 Lichen Planus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Aphthous Ulcers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Leukoplakia and Erythroplakia . . . . . . . . . . . . . . . . . . 71 Actinic Cheilitis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Black Hairy Tongue . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Squamous Cell Carcinoma . . . . . . . . . . . . . . . . . . . . . 72 Oral Candidiasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Foot and Leg Ulcers Venous Stasis Ulcers . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Arterial Ulcers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Neuropathic Ulcers. . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Skin in Aging Populations Common Clinical Problems in Older Skin . . . . . . . . . 74 Care of Aged Skin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Dermatologic Urgencies and Emergencies Erythema Multiforme, Stevens-Johnson Syndrome, and Toxic Epidermal Necrolysis . . . . . . . . . . . . . . . . . 61 Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Erythroderma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Hair Disorders Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Nonscarring Alopecias . . . . . . . . . . . . . . . . . . . . . . . . 66 Metabolic Imbalance and Medications . . . . . . . . . 66 Androgenetic Alopecia. . . . . . . . . . . . . . . . . . . . . 66 Alopecia Areata . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Telogen Effluvium. . . . . . . . . . . . . . . . . . . . . . . . 66 x
Dermatologic Diseases of Skin of Color Postinflammatory Hypo- or Hyperpigmentation. . . . . 76 Common Lesions in Skin of Color . . . . . . . . . . . . . . . 76 Keloids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Pseudofollicular Barbae . . . . . . . . . . . . . . . . . . . . 77 Acne Keloidalis Nuchae . . . . . . . . . . . . . . . . . . . . 77 Dermatosis Papulosa Nigra . . . . . . . . . . . . . . . . . 77 Skin Cancers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Vitiligo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Self-Assessment Test . . . . . . . . . . . . . . . . . . . . . . 81 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Dermatology
Approach to the Patient with Dermatologic Disease A complete skin examination takes on average 1 to 2 minutes to perform. Unfortunately, many physicians, perhaps because of lack of training or because of the lack of belief in its utility, routinely fail to check the skin during the course of a general medical examination. Space limitations prohibit inclusion of the essential techniques of performing a skin examination in this syllabus; however, readers are encouraged to learn more in the cited review (see Bibliography). The importance of examining the skin cannot be underestimated; not only can important dermatologic diagnoses be made, but the skin often reveals important clues to underlying medical conditions such as hematologic, rheumatologic, or other systemic illnesses. Most dermatologists believe that performing a complete skin examination may be a lifesaving procedure by allowing early detection of potentially lethal melanomas and other skin cancers. Unfortunately, data supporting this belief are lacking, and the U.S. Preventive Services Task Force has not found sufficient evidence to recommend routine skin screening of asymptomatic patients by internists. A prudent approach may be to perform complete screening skin examinations only on patients who are at high risk for developing skin cancers (Table 1). Another option is to screen only the high-risk areas of the body, such as sun-exposed areas in patients with sun damage as well as the backs of men and lower extremities of women, which statistically are sites of highest incidence for melanoma. Although most skin cancers, including melanoma, originate on sun-exposed skin, they can develop anywhere on the body, including the scalp, mucous membranes, and genitals. TA B L E 1 . Skin Cancer Risk Factors That Warrant Regular Skin Cancer Screening
History of multiple blistering sunburns Red or light hair; light-colored eyes Multiple atypical nevi History of melanoma History of nonmelanoma skin cancers Family history of skin cancers or melanoma Immunosuppression History of phototherapy
A complete skin examination requires examination of all these sites in addition to the more exposed areas of skin. A comprehensive skin examination may also be important when establishing the diagnosis and extent of many other skin diseases. For example, patients who present with the characteristic purple papules of lichen planus on the wrist may also have involvement of the scalp, oral mucosa, and genitals. Patients may not mention these symptoms because of embarrassment or because they have not considered a relationship between these symptoms and their initial problem. Although most skin conditions lack urgency, some need urgent or emergent intervention. Skin conditions that necessitate emergent dermatologic consultation include: • Widespread erythema or erythroderma (from drug reaction, toxin-producing bacterial infection, psoriasis) • Peeling, sloughing, or painful skin • Skin conditions with acute onset of mucosal erosion (mouth, eyes, genitals). More chronic involvement of these areas, such as that from lichen planus or pemphigus, needs prompt, but not necessarily emergent, evaluation. • Widespread blisters or pustules, especially when rapidly progressing • Retiform purpura (often indicates intravascular thrombosis or vasculitis) or skin necrosis (from thrombosis or intravascular infection, such as endocarditis or deep fungal infection) • Palpable purpura, particularly in patients with systemic illness or fever (vasculitis, sepsis) • Skin lesions of uncertain cause in any systemically ill patient, particularly if there is underlying immunosuppression, if there is a history of travel, or if the patient is taking systemic medications Worrisome pigmented lesions or other possibly malignant skin lesions require prompt, but not necessarily emergent, evaluation. Special consideration should be given to organ transplant recipients, who are at high risk for developing aggressive squamous cell carcinomas and other skin cancers, as well as infections, including deep fungal infections. Any rapidly growing nodule or plaque in a transplant recipient, particularly those in sun-exposed skin, should be evaluated promptly, ideally within a few days. Purpuric or necrotic skin lesions in transplant recipients are worrisome for systemic infection, particularly angioinvasive fungal infections, and should be seen emergently.
1
Therapeutic Principles in Dermatology
KEY POINTS
• Patients who present with erythroderma, skin pain, sloughing skin, mucosal erosions, widespread blisters or pustules, or retiform or palpable purpura should receive emergent referral to a dermatologist. • Transplant recipients with any rapidly growing nodule or lesion should be evaluated promptly.
Therapeutic Principles in Dermatology Treating dermatologic diseases is, at times, as much an art as a science. Choosing the best medications, whether topical or systemic, requires many considerations, including cost, patient preference, and other factors that will affect compliance. Many dermatologic diseases are rare, and good, randomized, placebo-controlled trials may never be available from which to determine best practices. As such, anecdotal data guide many treatment decisions, and many pharmacologic therapies are used off-label to treat dermatologic diseases, some of which have no FDA-approved treatments.
Topical Corticosteroids Topical corticosteroids are used to treat various dermatoses. The ideal corticosteroid is strong enough to treat the problem effectively without causing unnecessary or potentially
TA B L E 2 .
avoidable side effects. The ideal topical medication is also prescribed in a preparation that is appropriate for the location on which it is being used. Topical corticosteroids vary significantly in potency (Table 2). Clobetasol propionate, an ultrapotent corticosteroid, is approximately 1000 times stronger than over-thecounter hydrocortisone. Ultrapotent corticosteroids are appropriate for short-term use on many areas of the skin but should generally be avoided on the face, in intertriginous skin folds (groin and axilla), and on atrophic skin where absorption may be enhanced. Use of lower-potency corticosteroids is recommended in these areas. Absorption may also be enhanced from open skin or from mucous membranes; however, use of ultrapotent corticosteroids is now considered standard of care for treating certain vulvar diseases including lichen sclerosus. Most topical corticosteroids are available in a wide variety of preparations, including creams, ointments, gels, foams, and lotions. A few corticosteroids are embedded in occlusive tape or in peanut oil. The skin condition being treated, the body parts affected, and patient preference should all be considered when choosing an appropriate preparation. Creams are the most cosmetically elegant preparation, as they are easy to apply, absorb well, and usually leave no greasy residue. Creams are useful for treating most dermatoses on many areas of the body. One disadvantage of creams is that they often contain alcohol, and they may sting if applied to open areas of skin or mucous membranes. They also contain preservatives, which occasionally cause allergic contact dermatitis. Finally,
Potencies of Selected Commonly Prescribed Topical Corticosteroids
Class
Drug
Class 1: Superpotent
Clobetasol propionate 0.05% Betamethasone dipropionate ointment 0.05% Halobetasol propionate 0.05%
Class 2: High Potency
Betamethasone dipropionate cream 0.05% Fluocinonide 0.05% Desoximetasone 0.25%
Class 3: High Potency
Betamethasone valerate ointment 0.1% Triamcinolone acetonide ointment 0.1% Triamcinolone acetonide cream 0.5% Fluticasone propionate ointment 0.05%
Class 4: Medium Potency
Triamcinolone acetonide cream 0.1% Hydrocortisone valerate ointment 0.2% Fluocinolone acetonide ointment 0.025% Fluticasone propionate cream 0.05%
Class 5: Medium Potency
Betamethasone valerate cream 0.1% Hydrocortisone valerate cream 0.2% Triamcinolone acetonide lotion 0.1% Fluocinolone acetonide cream 0.025%
Class 6: Low Potency
Betamethasone valerate lotion 0.05% Desonide cream 0.05% Fluocinolone acetonide cream 0.01% Fluocinolone acetonide solution 0.05%
Class 7: Low Potency
Hydrocortisone 0.5-1.0%
2
This self-assessment test contains one-best-answer multiple-choice questions. Please read these directions carefully before answering the questions. Answers, critiques, and bibliographies immediately follow these multiple-choice questions. The American College of Physicians is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. The American College of Physicians designates MKSAP 16 Dermatology for a maximum of 10 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Earn “Same-Day” CME Credits Online For the first time, print subscribers can enter their answers online to earn CME credits in 24 hours or less. You can submit your answers using online answer sheets that are provided at mksap.acponline.org, where a record of your MKSAP 16 credits will be available. To earn CME credits, you need to answer all of the questions in a test and earn a score of at least 50% correct (number of correct answers divided by the total number of questions). Take any of the following approaches: ➢ Use the printed answer sheet at the back of this book to record your answers. Go to mksap.acponline.org, access the appropriate online answer sheet, transcribe your answers, and submit your test for same-day CME credits. There is no additional fee for this service. ➢ Go to mksap.acponline.org, access the appropriate online answer sheet, directly enter your answers, and submit your test for same-day CME credits. There is no additional fee for this service. ➢ Pay a $10 processing fee per answer sheet and submit the printed answer sheet at the back of this book by mail or fax, as instructed on the answer sheet. Make sure you calculate your score and fax the answer sheet to 215-351-2799 or mail the answer sheet to Member and Customer Service, American College of Physicians, 190 N. Independence Mall West, Philadelphia, PA 19106-1572, using the courtesy envelope provided in your MKSAP 16 slipcase. You will need your 10-digit order number and 8-digit ACP ID number, which are printed on your packing slip. Please allow 4 to 6 weeks for your score report to be emailed back to you. Be sure to include your email address for a response. If you do not have a 10-digit order number and 8-digit ACP ID number or if you need help creating a username and password to access the MKSAP 16 online answer sheets, go to mksap.acponline.org or email custserv@ acponline.org. CME credit is available from the publication date of July 31, 2012, until July 31, 2015. You may submit your answer sheets at any time during this period.
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Self-Assessment Test
Dermatology Self-Assessment Test
Each of the numbered items is followed by lettered answers. Select the ONE lettered answer that is BEST in each case.
Item 1 A 49-year-old woman is evaluated for a several-day history of pruritic lesions on the abdomen. She first noticed them when she returned from a business trip to a large northeastern city. She didn’t see any bugs in the hotel. Her husband is not itching and has no visible lesions, although he shared the same room and bed. She reports no new medications or exposures to other persons with similar rashes. Medical history is unremarkable, and she takes no medications. Skin findings on physical examination are shown.
is 84/min. BMI is 31. Skin on the lower legs feels somewhat thickened. Sensation in both feet is normal. Toes are warm to the touch. Ankle-brachial index measurement of the left leg is 0.9. Skin findings are shown (see bottom of previous column). Laboratory studies show a normal complete blood count. Which of the following is the most appropriate treatment? (A) (B) (C) (D)
Arterial revascularization Contact casting Intravenous vancomycin Unna boot compression
Item 3 A 30-year-old man presents with concern about nail changes. He underwent induction chemotherapy for acute myeloid leukemia approximately 1 month ago and has done well in the interim. He is currently afebrile, has no systemic complaints, and his vital signs are normal. His kidney and liver chemistry studies are normal. Nail findings are shown. Which of the following is the most appropriate treatment? (A) (B) (C) (D)
Oral doxycycline Oral ivermectin Topical permethrin cream Topical triamcinolone acetonide cream
Item 2 A 54-year-old woman is evaluated for an enlarging, painful ulcer on the left medial leg of 3 to 4 months’ duration. The ulcer has been unresponsive to several courses of oral cephalexin. Medical history is remarkable for a remote history of a deep venous thrombosis in the left leg. On physical examination, temperature is 37.0 °C (98.6 °F), blood pressure is 124/86 mm Hg, and pulse rate
Which of the following is the most likely diagnosis? (A) (B) (C) (D)
Beau lines Lichen planus Median nail dystrophy Psoriasis
Item 4 A 46-year-old woman is evaluated for a 4-day history of an intensely pruritic rash on her face and neck. She started using a new facial moisturizer about 1 week before the onset of the rash. She has stopped using the moisturizer, but the rash has persisted. She has treated the rash with calamine lotion without improvement. Medical history is otherwise unremarkable, and she takes no medications. On physical examination, she has poorly defined, red, weepy, eczematous-appearing patches on the cheeks and 83
Self-Assessment Test
Directions
Item 1
Answer:
D
Educational Objective: Treat bedbug bites. This patient has bedbug bites, which can be very itchy, and topical triamcinolone acetonide may help alleviate some of the pruritus. Oral antihistamines may also be beneficial. Left alone, bedbug bites will heal spontaneously in a matter of days. Bedbug bites can be recognized by their characteristic grouping in a somewhat linear pattern; they often leave a series of bites close together on the skin. A small punctum or bite mark may be visible in the center of the bump. Bedbug infestations are a significant and growing problem, particularly in large cities where infestations have been found in many public places including hotels, theatres, offices, and even department stores. Travelers may be bitten while visiting infested locations and may unwittingly bring the bedbugs home with them in their luggage. There is variation in the response that different individuals have to the bites, so it is possible for different persons sharing the same room to have reactions ranging from no visible marks to larger, urticarial wheals. Bedbugs do not actively infest the skin, so treatment with pediculicides such as topical permethrin and oral ivermectin is not indicated. Bites can become secondarily infected if scratched, but bites lacking surrounding cellulitis do not require treatment with antibiotics, such as doxycycline. Bedbugs have not, to date, been convincingly shown to be a vector of communicable disease. KEY POINT
• Topical corticosteroids and oral antihistamines may provide symptomatic relief of bedbug bites. Bibliography Goddard J, deShazo R. Bed bugs (Cimex lectularius) and clinical consequences of their bites. JAMA. 2009;301(13):1358-1366. [PMID: 19336711]
Item 2
Answer:
D
Educational Objective: Manage venous stasis ulcers with compression dressings. This patient has a venous stasis ulcer, and Unna boots provide compression to facilitate healing by minimizing vascular hypertension and pedal edema. Unna boots are multilayered compression bandages that traditionally consist of an inner layer of nonelastic zinc oxide bandage covered by an elastic, self-adherent wrap. The dressing is applied from the foot to just below the knee in a manner that creates a pressure gradient, with higher pressures at the ankle and lower foot and
progressively less pressure as the bandage progresses up the leg. Venous stasis ulcers commonly arise in patients with chronic venous hypertension, and a history of a deep venous thrombosis or other trauma in the affected limb is not uncommon. Venous stasis ulcers classically develop around the medial malleolus. The surrounding skin is frequently thickened with evidence of chronic hemosiderin deposition. Venous stasis ulcers may be associated with venous stasis dermatitis, which causes affected skin to become red, warm, and possibly tender and mimics cellulitis. Commercially available multi-component compression dressings have been shown to be more effective than single component compression dressings. A variety of wound dressings may be used to cover the ulcers under the compression dressing. None have been shown to produce superior results. Arterial revascularization is inappropriate treatment for this patient. Arterial insufficiency ulcers also commonly arise on the lower extremities, but they often develop over bony prominences or on the posterior calf. These ulcers may appear “punched-out” and are often very painful. The affected limb may be cool to touch, with poor capillary refill. Distal pulses may not be palpable. An ankle-brachial index of less than 0.9 is consistent with peripheral artery disease. Contact casting is used to redistribute pressure on the plantar feet of patients with neuropathic ulcers. It provides no benefit in the treatment of venous stasis ulcers. Distinguishing venous stasis dermatitis from cellulitis can be difficult, but the presence of chronic erythema in both lower legs, the absence of fever or leukocytosis, and the lack of response to appropriate antibiotic therapy strongly suggest that this is not an infectious process. As such, treatment with intravenous vancomycin is not indicated. KEY POINT
• Compression therapy to minimize vascular hypertension and edema is an essential component of the treatment of venous stasis ulcers. Bibliography van Gent WB, Wilschut ED, Wittens C. Management of venous ulcer disease. BMJ. 2010;341:c6045. [PMID: 21075818]
Item 3
Answer:
A
Educational Objective: Diagnose Beau lines. This patient has Beau lines, which are transverse linear depressions that occur in the setting of severe systemic stress or illness, such as chemotherapy or sepsis. They are caused by a temporary disruption of nail production in the 105
Answers and Critiques
Answers and Critiques