Section 3: Scabies, Pediculosis, Lyme Disease, Toxin Mediated Diseases and Skin Cancers Flashcards Preview

Dermatology USMLE Step 3 > Section 3: Scabies, Pediculosis, Lyme Disease, Toxin Mediated Diseases and Skin Cancers > Flashcards

Flashcards in Section 3: Scabies, Pediculosis, Lyme Disease, Toxin Mediated Diseases and Skin Cancers Deck (15):
1

Diagnosis of scabies

Rx of scabies

Rx of Norwegian scabies

Scabies is confirmed by scraping out the organism after mineral oil is applied to a burrow.

Treatment is with

  • Permethrin
  • Lindane has equal efficacy but greater toxicity; thus, it is not the best initial therapy.
  • Ivermectin orally.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 8964-8968). Kaplan Publishing. Kindle Edition.

3

Rx of pediculosis

  • Permethrin.
  • Lindane has equal efficacy but greater toxicity; thus, it is not the best initial therapy.
  • Pediculosis can be treated with over-the-counter pyrethrins.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 8977-8979). Kaplan Publishing. Kindle Edition.

4

Rx of Lyme disease

  • Doxicycline
  • Amoxicillin
  • Cefuroxime

5

Toxic Shock Syndrome (TSS)

TSS is caused by Staphylococcus attached to a foreign body. Nasal packing, retained sutures, or any other form of surgical material retained in the body can promote the growth of the type of Staph that produces the toxin.

How is a diagnosis of TSS made

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 8990-8992). Kaplan Publishing. Kindle Edition.

Because there is no single specific test, cases are matters of definition. The definition of a case of toxic shock syndrome is as follows

  • Fever > 102 ° F
  • Systolic blood pressure < 90
  • Desquamative rash
  • Vomiting
  • Involvement of the mucous membranes of the eye, mouth, and genitals
  • Increase in creatinine, CPK, and liver function tests
  • Decrease in the platelet count
  • Can cause central nervous system dysfunction, such as confusion.

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 8994-9002). Kaplan Publishing. Kindle Edition.

6

Rx of TSS

  1. Vigorous fluid resuscitation
  2. Pressors, such as dopamine
  3. Antistaphylococcal medications, such as
    • Oxacillin
    • Nafcillin, or
    • Cefazolin
    • Vancomycin (MRSA)
    • Linezolid (MRSA)

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9003-9013). Kaplan Publishing. Kindle Edition.

7

Staphylococcal Scalded Skin Syndrome (SSSS)

SSSS is mediated by a toxin from Staphylococcus. It presents with loss of the superficial layers of the epidermis in sheets and Nikolsky’s sign. SSSS differs from other conditions as follows: Unlike TSS, SSSS presents with normal blood pressure and no involvement of the liver, kidney, bone marrow, or central nervous system. Unlike TEN, which results from drug toxicity, SSSS iscaused by an infection. In addition, SSSS only splits off the superficial granular layer of skin and is not a full thickness split, such as in TEN.

Unit to manage patients

Rx

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9013-9024). Kaplan Publishing. Kindle Edition.

  • Burn unit
  • Oxacillin/ nafcillin or other antistaphylococcal antibiotics

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9013-9024). Kaplan Publishing. Kindle Edition.

 

8

Rx of anthrax

Ciprofloxacin or doxycycline is the treatment.

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9013-9024). Kaplan Publishing. Kindle Edition.

9

Features of benign lesiosns

Diagnosis

  • They do not grow in size.
  • They have smooth, regular borders
  • Their diameter is usually < 1 cm
  • They are homogenous in color, and the color remains constant

 

Biopsy

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9029-9032). Kaplan Publishing. Kindle Edition.

10

Melanoma

These malignant lesions grow in size, have irregular borders, are uneven in shape, and have inconsistent coloring.

  1. Diagnostic test
  2. Most important prognostic factor
  3. Rx
  4. Role of interferon

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9033-9047). Kaplan Publishing. Kindle Edition.

  1. Biopsy with a full thickness sample
  2. Tumor thickness
  3. Excision
  4. Interferon seems to reduce the recurrence rates of melanoma

 

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9033-9047). Kaplan Publishing. Kindle Edition.

11

 Seborrheic Keratosis

This is a benign condition with hyperpigmented lesions occurring in the elderly with a “stuck on” appearance. They are most common on the face, shoulders, chest, and back.

  1. Rx
  2. Basis for Rx
  3. Relationship with actinic keratosis
  4. Relationship with Seborrheic keratosis

  1. Removed with liquid nitrogen or curettage
  2. Cosmetic purposes. They have no malignant potential
  3. None
  4. None

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9033-9047). Kaplan Publishing. Kindle Edition.

12

Actinic Keratosis

Actinic keratoses are precancerous lesions occurring on sun-exposed areas exposed areas of the body in older persons. They occur more often in those with light skin color. Although they are usually asymptomatic, they can be tender to the touch.

  1. How to prevent progression and recurrences
  2. Rx

  1. Therapy is universally with sunscreen to prevent their progression and recurrence
  2. Lesions should be removed with
    • Cryotherapy
    • Topical 5 fluorouracil (5FU)
    • Imiquimod
    • Topical retinoic acid derivatives
    • Curettage

 

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9047-9058). Kaplan Publishing. Kindle Edition.

 

13

Squamous Cell Carcinoma

Squamous cell carcinoma develops on sun-exposed skin surfaces in elderly patients.

  1. Makes up what percent of all skin cancers?
  2. Most common site?
  3. Major risk factor
  4. True or False: lesion ulceration is common
  5. Percent that metastasize
  6. Diagnostic test
  7. Rx
  8. Alternative Rx

  1. 10– 25 percent are squamous cell
  2. The lip
  3. Tobacco
  4. True
  5. 3 – 7 percent (metastasis is rare)
  6. Biopsy
  7. Surgical removal
  8. Radiation

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9047-9058). Kaplan Publishing. Kindle Edition.

14

Basal cell carcinoma

Has a shiny or “pearly” appearance

  1. Makes up what percent of all skin cancers?
  2. Percent that metastasize
  3. Diagnostic test
  4. Rx
  5. Describe the technique

  1. 65 – 80 percent
  2. < 0.1 percent
  3. Shave or punch biopsy
  4. Surgical removal: Mohs microsurgery has the greatest cure rate
  5. In Mohs microsurgery, instant frozen sections are done to determine when enough tissue has been removed to give a clean margin

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9060-9070). Kaplan Publishing. Kindle Edition.

15

 Kaposi’s Sarcoma:  purplish lesions found on the skin

  1. Commonly seen in which group of patients
  2. Causative organism
  3. Best therapy
  4. If (3) fails, what is the next step

  1. HIV Patients with CD4 counts < 100
  2. Human herpes virus 8
  3. Best therapy is to start antiretroviral therapy and raise the CD4 count
  4. The specific chemotherapy for Kaposi’s sarcoma
    • Liposomal Adriamycin
    • Vinblastine

 

 

 

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 9060-9070). Kaplan Publishing. Kindle Edition.

16

Immunocompromised patients, such as those with HIV, are particularly vulnerable to an extremely exuberant form of scabies with severe crusting known as ---

Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kaplan Medical Usmle Master the Boards Step 3) (Kindle Locations 8961-8963). Kaplan Publishing. Kindle Edition.

Norwegian scabies