Dermatological disease! Flashcards
A 50yo patient is concerned about a plaque her husband noticed on her back. It is flat/brownish, sharply demarcated, and appears “stuck on” with a grainy appearing surface, almost like a raisin.
What is the most likely cause? POM?
Sebborheic Keratosis (benign) POM: shave biopsy, excision, curretage
What is solar lentigo?
hyperpigmented round macules on sun damaged skin
Benign (not prelamlignant) though larger ones ca be difficult to distinguish from malignant melanoma
What is an epidermal cyst? POM? What is the smaller version of this called?
vSlowly growing round firm yellow or flesh-coloured intradermal or subcutaneous tumour
POM: incision to remove
Smaller version: millium
In which population are milliums MC?
Newborns (self-limiting)
Can also arise sponteously following trauma)
What is a keratocanthoma? POM?
Rapidly growing, firm, dome-shaped nodule 1-2cm with central keratin filled crater
Located on sun-exposed skin of elderly
Grows to full-size in 2-4mo, then regresses
POM: excision/cauterization
Image: What is a keratocanthoma? POM?
What is the name for the benign soft yellow papules 2-5mm usually found on the face? What malignant condition are they commonly mistaken for?
Sebaceous hyperplasia
BCC
A patient is worried because the hyper-pigmented papillomatous birth mark on their stomach has slowly become more prominant with age. It is well-demarcated and linearly arranged. What is the most likely cause? POM?
Epiderma nevus (benign) POM: laser, electrodessication, or cryotherapy
There are 2 types of benign melanocytic lesions which are characterized by multple small macules. What are the 2 types and how can you tell the difference between them?
- Simple lentigo: do not darken or miltiply with sun exposure, more scattered
- Ephelis (freckles): darken & multiple with sun exposure, concentrated on sun-exposed surfaces
MC locations for mongolian spot/nevus ito/ota
Lumbosacral region (mongolian spot)
Face (nevus of ota)
Shoulder (nevus of ito)
True or false: mongolian spots can change significantly throughout childhood
True - usually present at birth and disappears within 5 years, second peak in appearance in adolescence
Cafe-au-lait spots are associated with which condition?
Neurofibromatosis (if >6 spots >1.5cm)
Which benign melanocyte lesion appears in the 2nd decade in males and can enlarge in the 4th decade?
Becker’s melanosis/nevus
What are the 7 types of melanocyte nevi? At what ages are they seen?
- Congenital: present at birth
- Junctional (1.5-4y): flat, well-circumsribed nests of nevus cells at the interface of the epidermis and dermis
- Compound (5-40y): nevus cells migrate to dermis, lesion becomes elevated
- Dermal (10-50yo): nevus loses all connection with overlying epidermis, becomes flesh coloured
- Dysplastic nevus (8-80yo): starts flat-irregular elevation and outline, expands
- Blue nevus (1.5-40yo): common in persons of asian descent
- Halo navus (2-30yo): may remain same or mole may disappear
Patients with Turner syndrome have an increased incidence of which type of nevus?
Halo
What is the medical term for the port wine stain birth mark MC seen at the nape of the neck?
Nevus flammeus
What is the name for the soft, round, compressible dark blue papule commonly seen on the face, lips, and ears of >65yo?
Venous lake
What is a senile hamangioma?
AKA cherry angioma
idiopathic, usually on trunk beginning in early adulthood and increasing in number with age-frequency
Bright red dome shaped papules 1-5mm
How can you tell the difference between capillary hemangioma (strawberry mark) and nevus flammeus (port wine stain)?
Hemangioma will blanch when pressed
Which benign vascular skin lesion may require surgical intervention?
Cavernous hemangioma (AKA Bag of worms) Caused by proliferation of thick-walled blood vessels
Which 3 benign vascular lesions require excision?
Pyogenic granuloma (photo)
Angiokeratoma
Lymphangioma
What are the 3 benign tumours of fibrous tissue? What is their etiology?
- Dermatofibroma: trauma (splinter, insect bite, cyst)
- Keloid: trauma
- Acrochordon: AKA skin tag - idiopathic
What are the MC complications of chicken pox in children? In adults?
Children: encephalitis
Adults: pneumonia
Tc for herpes zoster
Compress
Corticosteroids
IV acyclovir
Opthalmological consult
What is molluscum contagiosum? How is it transmitted? Treatment?
Asymptomatic, shiny whitish pearly umbilicated papules caused by DNA Pox virus
Transmission: Direct contact
Tx: curretage/liquid nitrogen
How is tinea capitis diagnosed?
Wood’s Lamp: filtered by Wood’s glass containing 9% nickel oxide that transmits rays of a wavelength >365nm which in a darkened room causes hairs to fluoresce bright green
Which infection is associated with poor hygeine with shaving?
Tinea barbae
S&S Tinea corporis
- Red to pink annular patches and plaques
- Raised scaly borders that tend to clear centally
MC in farm children with infected animals
What is the medical term for “jock itch”? What causes it?
Tinea cruris
Caused by wearing tight-fitting clothes for extended periods, sharing clothing with others
Contagious infection transmitted by contaminated towels, hotel bedroom sheets, or autoinoculation from hands or feet
2 MC causative organism of tinea pedis/manis/cruris
T. Rubrum
T mentagrophytes
What is the skin lesion associated with HIV infection? Prognosis?
Kaposi’s sarcoma
Mean survival rate 15-24mo
MC presentation of psoriasis
Scaly plaques on extensor surfaces, BL, symmetric
Nails may also exhibit pitting
Risk factors for psoriasis aggravation
Age: 16-22, 57-60 (bimodal) Female Family hx (one parent = 30% chance, 2 parents = 50-70%) IBD Local Trauma Infection HIV Drugs Psychogenic/emotiona factors Smoking/alcohol Endocrine (puberty, menopause)
Your 18yo female patient reports that she noticed a salmon-coloured macule which has enlarged over the past few days and has formed a collar of fine scale. It is ithcy but otherwise doesn’t bother her.
What is this condition? Prognosis?
Pityriasis Rosea: idiopathic condition thought to be caused by a virus
Prognosis: self-resolving within 6wks, but first will form a christmas tree pattern on torso
What is Lichen Planus?
Itchy, papular eruption characterized by purple colour, polygonal shape, and fine scale.
MC on flexor surfaces of upper extremities, genetalia, and mucous membranes (tongue, buccal mucosa)
Self-resolving in 8-12mo
What are the 2 types of premalignant epithelial tumours?
- Solar (actinic) keratosis
2. SCC in situ
Biggest risk factor for actinic keratosis
Sun exposure - 60% of individuals older than 40 who are predisposed have at least one actinic keratosis
S&S of Actinic Keratosis
Erythematous, slightly elevated or wart-ike papules/plaques covered by adherent scale
Black/black in colour and can be single or multiple
S&S squamous cell carcinoma in situ (AKA Bowen disease)
Solitary, sharply marginated, slightly elevated erythematous plaque with surface scaling/crusting
3 MC malignant epithelial tumours
Basal cell carcinoma (MC)
Squamous cell carcinoma (2nd MC)
Malignant melanoma
S&S Basal cell carcinoma
Cherry danish (skin coloured papule/plaque with rolled translucent outer border and depressed, eroded centre)
3 Variants of BCC
- Superficial: scaly plaque slowly enlarging wiht thread-like telangiectasia, usually on trunk
- Sclerosing: flesh-coloured shiny papule/plaque with appendages that can extend beyind the lesion margins
- Pigmented: Flecks/stipples of pigment
S&S SCC
Begins as scaly red papule which eventually ulcerates and invades underlying tissue
True or false: SCC that arise from sun exposure rarely metastasize
True! Only 1%. Other causes have higher rate (up to 25%)
Risk factors for malignant melanoma
Dysplastic nevi Family hx Blonde/redhead Multiple melanocytic nevi (>100) Hx blistering sunburns
MC age to get malignant melanoma?
30-40yo (66%)
ABCDEs of melanoma
asymmetry, border (irregular), color (variable), diameter (>6mm), evolution
Types of malignant melanoma
- Superficial spreading melaoma (MC) - usu extremities and back
- Lentigo maligna melanoma - elderly, but least likely to go vertical
- Nodular melanoma - UV exposed areas. Only vertical phase usu at presentation
- Acral lentiginous melanoma - AA, Asia, no relaton to sun. Palms, soles, beneath nails. POOR PROGNOSIS.
Impetigo is caused by which 2 organisms?
Beta-hemolytic strep
Staph aureus
True or false: impetigo is contagious
True! Spread through contact with clothing, bed linens, close contact
MC cause of folliculitis
Staph aureus
What is paronychia?
infection of the nail bed (disruption between seal of proximal nail fold and nail plate)
What is erysipelas? MC causative organism?
infection of the skin and subcutaneous tissues
requires immediate antibiotic therapy
MC: B-hemolytic strep
S&S cellulitis
Red linear streaks (lymphangitis) may extend proximally up affected limb
Fever, elevated WBC, regional lymphadenopathy
Poorly demarcated, erythematous, tender, warm edematous
