Vascular tumours of the skin, skin infections, cutaneous mycoses

Question 1

Angiosarcoma definition

Answer 1

Rare blood vessel malignancy typically occurring in the head, neck, and breast areas
Usually in older adults, on sun-exposed areas
Very aggressive and difficult to resect due to delay in diagnosis

Question 2

Associations of angiosarcoma

Answer 2

Associated with radiation therapy and chronic postmastectomy lymphedema

Question 3

Stewart-Treves syndrome definition

Answer 3

Cutaneous angiosarcoma developing after chronic lymphedema

Question 4

What is hepatic angiosarcoma associated with

Answer 4

Vinyl chloride and arsenic exposures

Question 5

Bacillary angiomatosis definition

Answer 5

Benign capillary skin papules found in patients with AIDS
Caused by Bartonella infections
Frequently mistaken for Kaposi sarcoma, but has neutrophilic infiltrate

Question 6

Cherry hemangioma definition

Answer 6

Benign capillary hemangioma commonly appearing in middle-aged adults
Does not regress
Frequency increased with age

Question 7

Glomus tumour definition

Answer 7

Benign, painful, red-blue tumour, commonly under fingernails
Arises from modified smooth muscle cells of the thermoregulatory glomus body

Question 8

Kaposi sarcoma definition

Answer 8

Endothelial malignancy most commonly affecting the skin, mouth, GI tract, respiratory tract

Question 9

Epidemiology of Kaposi sarcoma

Answer 9

Classically seen in older Eastern European males, patients with AIDS, and organ transplant patients

Question 10

Associations & type of infiltrate in Kaposi

Answer 10

Associated with HHV-8 and HIV
Lymphocytic infiltrates, unlike bacillary angiomatosis

Question 11

Pyogenic granuloma definition & association

Answer 11

Polypoid lobulated capillary hemangioma that can ulcerate and bleed
Associated with trauma and pregnancy

Question 12

Strawberry (infantile) hemangioma definition

Answer 12

Benign capillary hemangioma of infancy
Appears in first few weeks of life (1/200 births); grows rapidly and regresses spontaneously by 5–8 years old

Question 13

Define Impetigo and the organisms involved

Answer 13

Skin infection involving superficial epidermis
Usually from S aureus or S pyogenes
Highly contagious

Question 14

Clinical findings in impetigo and define bullous impetigo

Answer 14

Honey-coloured crusting.
Bullous impetigo has bullae and is usually caused by S aureus

Question 15

Define Erysipelas & presentation

Answer 15

Infection involving upper dermis and superficial lymphatics, usually from S pyogenes
Presents with well-defined, raised demarcation between infected and normal skin

Question 16

Define cellulitis

Answer 16

Acute, painful, spreading infection of deeper dermis and subcutaneous tissues
Usually from S pyogenes or S aureus
Often starts with a break in skin from trauma or another infection

Question 17

define abscess

Answer 17

Collection of pus from a walled-off infection within deeper layers of skin
Offending organism is almost always S aureus

Question 18

define necrotizing fasciitis

Answer 18

Deeper tissue injury, usually from anaerobic bacteria or S pyogenes
Pain may be out of proportion to exam findings

Question 19

what does necrotizing fasciitis result in

Answer 19

Crepitus from methane and carbon dioxide production
“Flesh-eating bacteria”
Causes bullae & skin necrosis = violaceous colour of bullae, surrounding skin (Surgical emergency)

Question 20

Staphylococcal scalded skin syndrome

Answer 20

Exotoxin destroys keratinocyte attachments in stratum granulosum only (vs toxic epidermal necrolysis, which destroys epidermal-dermal junction)
Commonly seen in newborns and children/adults with renal insufficiency

Question 21

Clinical findings of staph scalded skin syndrome

Answer 21

Characterized by fever and generalized erythematous rash with sloughing of the upper layers of the epidermis that heals completely
⊕ Nikolsky sign (separation of epidermis upon manual stroking of skin)

Question 22

Define herpes infection and where they occur

Answer 22

Herpes virus infections (HSV-1 and HSV-2) of skin can occur anywhere from mucosal surfaces to normal skin
These include herpes labialis, herpes genitalis, herpetic whitlow (finger)

Question 23

Molluscum contagiosum

Answer 23

Umbilicated papules caused by a poxvirus
While frequently seen in children, it may be sexually transmitted in adults

Question 24

Varicella zoster

Answer 24

Causes varicella (chickenpox) and zoster (shingles)

Question 25

Varicella presentation

Answer 25

Varicella presents with multiple crops of lesions in various stages from vesicles to crusts

Question 26

Zoster presentation

Answer 26

Zoster is a reactivation of the virus in dermatomal distribution (unless it is disseminated)

Question 27

Hairy leukoplakia

Answer 27

Irregular, white, painless plaques on lateral tongue that cannot be scraped off
EBV mediated
Occurs in patients living with HIV, organ transplant recipients
Contrast with thrush (scrapable) and leukoplakia (precancerous)

Question 28

Define Tinea (dermatophytes)

Answer 28

Clinical name for dermatophyte (cutaneous fungal) infections
Dermatophytes include Microsporum, Trichophyton, and Epidermophyton
Associated with pruritus

Question 29

Dx of tinea

Answer 29

Branching septate hyphae visible on KOH preparation with blue fungal stain

Question 30

Tinea capitis

Answer 30

Occurs on head, scalp
Associated with lymphadenopathy, alopecia, scaling

Question 31

Tinea corporis

Answer 31

Occurs on body (usually torso)
Characterized by enlarging erythematous, scaly rings (“ringworm”) with central clearing
Can be acquired from contact with infected pets or farm animals

Question 32

Tinea cruris

Answer 32

Occurs in inguinal area (“jock itch”)
Often does not show the central clearing seen in tinea
corporis

Question 33

Tinea pedis

Answer 33

Three varieties (“athlete’s foot”): Interdigital most common Moccasin distribution
Vesicular type

Question 34

Tinea unguium

Answer 34

Onychomycosis; occurs on nails

Question 35

Tinea (pityriasis) versicolor organism and pathogenesis

Answer 35

Caused by Malassezia spp. (Pityrosporum spp.), a yeastlike fungus (not a dermatophyte despite being called tinea)
Degradation of lipids produces acids that inhibit tyrosinase (involved in melanin synthesis) = hyper/hypopigmentation, and/or pink patches can also occur from inflammatory response
Less pruritic than dermatophytes

Question 36

When does tinea versicolor commonly occur and how does it appear on microscopy

Answer 36

Can occur any time of year, but more common in summer (hot, humid weather)
“Spaghetti and meatballs” appearance on microscopy

Question 37

Tx of tinea versicolor

Answer 37

Selenium sulfide, topical and/or oral antifungal medications