Common Skin Lesions

Question 1

Dermatofibroma

Answer 1

presentations; dimple sign (Fitzpatrick’s sign)- lateral compression causes dimpling of the lesion
pathophys: benign, due to fibroblast proliferation in the dermis

Question 2

Skin tags

Answer 2

• acrochordons
• fibroepithelial polyps
• soft fibromas
• pedunculated lipofibromas
• cutaneous papillomas

Question 3

Seborrheic keratosis

Answer 3

• class “stuck on” appearance
• Sudden appearance can be associated with gastric adenocarcinoma
• Pathophys;rapid increase of keratinocytes and melanocytes

Question 4

Actinic Keratosis

-Premalignant

Answer 4

• sand-paper like lesion
• scaley erythematous papule
• area of sun-damaged skin
• Pathophys: UVB radiation damage to keratinocyte from repeated sun exposure
• risk of transformation of AK to SCC
• rare in darker skin as melanin is protective

Question 5

Keratoacanthoma

-Malignant

Answer 5

• rapidly growing, dome-shaped, skin-coloured nodule with central keratin-filled crater
• remember volcano
• pathophys: epithelial neoplasm with atypical keratinocytes in epidermis, low grade variant of SCC
• Mgm: Surgical excision or saucerization (shave biopsy)

Question 6

DDx of Hyperpigmented Macules

Answer 6

• purpura (solra, ASA, anti-coagulants, steroids, hemosiderin stain)
• post-inflammatory
• melasma
• melanoma
• fixed drug eruption

Question 7

Hemangioma

Includes: cavernous hemangioma, capillary/infantile hemangioma, spider hemangioma

Answer 7

• red or blue SC mass, blanches with oressure, feels like a “bag of worms” when palpated.
• pathophys: benign vascular tumour

Question 8

*Acne Vulgaris/Common Acne

Answer 8

type 1: comedonal, sparse, no scarring
type 2: comedonal, papular, moderate +/-little scaring
type 3: comedonal, papular, and pustular, with scarring
type 4: nodulocystic acne, risk of severe scarring

Question 9

*Mgm of Acne Vulgaris/Common Acne

Answer 9

Mild Topical OTC: benzoyl peroxide (BPO), Salicylic acid
Mild Topical Rx: antimicrobial (Clindamycin), retinoid
Moderate: Tetracycline/Minocycline*/Doxycycline
Severe: Isotretinoin

Question 10

*Isotretinoin & Pregnancy

Answer 10

• associated w/ spontaneous abortion and major birth defects such as facial dysmorphism and cognitive impairment
• R/O pregnancy before starting
• Ideally pt should use 2 forms of contraception while on it