Dermatology

Question 1

small violet papules with fine white streaking
can be located on ventral wrists or genitalia

Pruritic

Answer 1

Lichen planus

-5 P’s = Pruritic, polygonal, purple papules, plaques

Question 2

Scaly spot on sun exposed skin that stings
macule with thick scale on erythematous base

identify what this is and what it can develop into

Answer 2

Actinic Keratosis

can develop into Squamous Cell Carcinoma

Question 3

identify:
starts as large oval patch then progresses to several smaller lesions

rash is mildly pruritic and nontender, small erythematous plaques

Answer 3

Pityriasis Rosea - begins with “herald” patch

-leaves “christmas tree” like appearance

Question 4

Identify dz and underlying problem:
young pt “sunburns too easily” - minimal sun causes skin to be red and scaly
skin = thin and hyperpigmented, nevi that are enlarging rapidly

Answer 4

Xeroderma pigmentosum
–NUCLEOTIDE EXCISION repair
DNA damage from UV sunlight

Question 5

Pt present with rash
pruritis red bumps on cheek. Multiple erythematous pustules on right cheek that range from 2-3 mm each, denies tenderness

identify dz and cause

Answer 5

Folliculitis - infection of hair follicles

most common cause = S. aureus

Question 6

Pt with hx of alot of sun exposure presents with nevus that measures 9mm in diameter. lesion is asymmetric and has a variety of red and brown coloration. dx of malignant melanoma with a thickness of .70mm is made. what is the most likely histologic subtype?

Answer 6

superficial spreading - period of long radial growth prior to radial growth begins

Question 7

What is the mechanism of an infant born with very pale skin, white hair, pink-colored irises?

Answer 7

Oculocutaneous albinism - inherited abnormality of melanin syntehsis

–caused by decrease in the activity level of the tyrosinase enzyme

Question 8

24 yr old presents w rash
rash on chest began 4 weeks ago.
Pruritis, growing slowly in size - erythematous-tan patch with peripheral scaling

Answer 8

Tinea corporis - annular, pruritic rash with peripheral scaling that gradually expands

Question 9

sudden outbreak of pruritic rash on palms and sole. skin shows “target” lesions with dark/blistered center, dark red ring around center, ring of erythema at the periphery

what is this lesion call what is the most common cause?

Answer 9

Erythema multiforme

–most common cause = HSV

Question 10

identify dx
26 year old female present with non-tender/pruritic white flaking. Skin shows white, scaly patches on a non-erythematous base on the scalp. Bilateral external ear canals and axillae are also affect with erythema and overlying scaly patches, no evidence of bleeding

Answer 10

Seborrheic dermatitis
–recurrent, found on scalp during adolescence and early adulthood.

• white, scaly, flaking on scalp
• skin lesions are erythematous w overlying scaling in areas of sebaceous glands

Question 11

identify:

raised bumps in webs of fingers and toes. pt exposure to homeless shelters, low hygiene

Answer 11

Scabies - rash from reaction caused by deposition of eggs and feces

Question 12

Identify PRECURSOR lesion:
Farmer w enlarging ulcerating lesion. Bx shows atypical keratinocytes that are slightly enlarged w abundant amounts of cytoplasm with keratinization

Answer 12

Actinic Keratosis

–Bx shows Squamous cell Ca

Question 13

What type of skin cancer has the best prognosis?

Answer 13

Basal cell carcinoma - almost never metastasizes

Question 14

What med should be used to treat fungal growth under toenails (onychomycosis)?

what is mechanism

Answer 14

Terbinafine (lamisil)
—inhibits squalene epoxidase - inhibits squalene into lanosterol

–itraconazole can be used but not as effective